Bump to 1.92.0

A tiny release, but there's new features so it's technically a minor
bump.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -12,4 +12,5 @@ labels: bug
 ## Useful information to include:
  - Minecraft version
  - CC: Tweaked version
+ - Logs: These will be located in the `logs/` directory of your Minecraft instance. Please upload them as a gist or directly into this editor.
  - Detailed reproduction steps: sometimes I can spot a bug pretty easily, but often it's much more obscure. The more information I have to help reproduce it, the quicker it'll get fixed.

.github/workflows/main-ci.yml

@@ -10,10 +10,10 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - name: Set up JDK 1.8
+    - name: Set up Java 8
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 8
 
     - name: Cache gradle dependencies
       uses: actions/cache@v1
@@ -32,12 +32,11 @@ jobs:
         name: CC-Tweaked
         path: build/libs
 
-  lint-lua:
-    name: Lint Lua
-    runs-on: ubuntu-latest
+    - name: Upload Coverage
+      run: bash <(curl -s https://codecov.io/bash)
 
-    steps:
-    - uses: actions/checkout@v1
+    - name: Generate Java documentation stubs
+      run: ./gradlew luaJavadoc --no-daemon
 
     - name: Lint Lua code
       run: |

.github/workflows/make-doc.yml

@@ -2,7 +2,9 @@ name: Build documentation
 
 on:
   push:
-    branches: [ master ]
+    branches:
+    - master
+    - mc-1.15.x
     tags:
   release:
     types: [ published ]
@@ -15,6 +17,25 @@ jobs:
     steps:
     - uses: actions/checkout@v1
 
+    - name: Set up Java 8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 8
+
+    - name: Cache gradle dependencies
+      uses: actions/cache@v1
+      with:
+        path: ~/.gradle/caches
+        key: ${{ runner.os }}-gradle-${{ hashFiles('gradle.properties') }}
+        restore-keys: |
+          ${{ runner.os }}-gradle-
+
+    - name: Build with Gradle
+      run: ./gradlew compileJava --no-daemon || ./gradlew compileJava --no-daemon
+
+    - name: Generate Java documentation stubs
+      run: ./gradlew luaJavadoc --no-daemon
+
     - name: Build documentation
       run: |
         test -d bin || mkdir bin

.gitignore

@@ -4,6 +4,7 @@
 /build
 /out
 /doc/**/*.html
+/doc/javadoc/
 /doc/index.json
 
 # Runtime directories

CONTRIBUTING.md

@@ -10,7 +10,7 @@ do use the issue templates - they provide a useful hint on what information to p
 
 ## Developing
 In order to develop CC: Tweaked, you'll need to download the source code and then run it. This is a pretty simple
-process.
+process. When building on Windows, Use `gradlew.bat` instead of `./gradlew`.
 
  - **Clone the repository:** `git clone https://github.com/SquidDev-CC/CC-Tweaked.git && cd CC-Tweaked`
  - **Setup Forge:** `./gradlew build`
@@ -29,8 +29,13 @@ are run whenever you submit a PR, it's often useful to run this before committin
  - **[illuaminate]:** Checks Lua code for semantic and styleistic issues. See [the usage section][illuaminate-usage] for
    how to download and run it.
 
+## Translations
+Translations are managed through [Weblate], an online interface for managing language strings. This is synced
+automatically with GitHub, so please don't submit PRs adding/changing translations!
+
 [new-issue]: https://github.com/SquidDev-CC/CC-Tweaked/issues/new/choose "Create a new issue"
 [community]: README.md#Community "Get in touch with the community."
 [checkstyle]: https://checkstyle.org/
 [illuaminate]: https://github.com/SquidDev/illuaminate/
 [illuaminate-usage]: https://github.com/SquidDev/illuaminate/blob/master/README.md#usage
+[weblate]: https://i18n.tweaked.cc/projects/cc-tweaked/minecraft/

README.md

@@ -1,4 +1,4 @@
-# ![CC: Tweaked](logo.png)
+# ![CC: Tweaked](doc/logo.png)
 [![Current build status](https://github.com/SquidDev-CC/CC-Tweaked/workflows/Build/badge.svg)](https://github.com/SquidDev-CC/CC-Tweaked/actions "Current build status") [![Download CC: Tweaked on CurseForge](http://cf.way2muchnoise.eu/title/cc-tweaked.svg)](https://minecraft.curseforge.com/projects/cc-tweaked "Download CC: Tweaked on CurseForge")
 
 CC: Tweaked is a fork of [ComputerCraft](https://github.com/dan200/ComputerCraft), adding programmable computers,
@@ -50,12 +50,12 @@ I'd generally recommend you don't contact me directly (email, DM, etc...) unless
 report exploits). You'll get a far quicker response if you ask the whole community!
 
 ## Using
-If you want to depend on CC: Tweaked, we have a maven repo. However, you should be wary that some functionality is only
-exposed by CC:T's API and not vanilla ComputerCraft. If you wish to support all variations of ComputerCraft, I recommend
-using [cc.crzd.me's maven](https://cc.crzd.me/maven/) instead.
+CC: Tweaked is hosted on my maven repo, and so is relatively simple to depend on. You may wish to add a soft (or hard)
+dependency in your `mods.toml` file, with the appropriate version bounds, to ensure that API functionality you depend
+on is present.
 
 ```groovy
-dependencies {
+repositories {
   maven { url 'https://squiddev.cc/maven/' }
 }
 

build.gradle

@@ -9,7 +9,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.google.code.gson:gson:2.8.1'
-        classpath 'net.minecraftforge.gradle:ForgeGradle:3.0.169'
+        classpath 'net.minecraftforge.gradle:ForgeGradle:3.0.179'
         classpath 'net.sf.proguard:proguard-gradle:6.1.0beta2'
         classpath 'org.ajoberstar.grgit:grgit-gradle:3.0.0'
     }
@@ -17,6 +17,7 @@ buildscript {
 
 plugins {
     id "checkstyle"
+    id "jacoco"
     id "com.github.hierynomus.license" version "0.15.0"
     id "com.matthewprenger.cursegradle" version "1.3.0"
     id "com.github.breadmoirai.github-release" version "2.2.4"
@@ -32,6 +33,8 @@ version = mod_version
 group = "org.squiddev"
 archivesBaseName = "cc-tweaked-${mc_version}"
 
+sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8'
+
 minecraft {
     runs {
         client {
@@ -48,7 +51,7 @@ minecraft {
 
         server {
             workingDirectory project.file("run/server-${mc_version}")
-            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'
+            property 'forge.logging.markers', 'REGISTRIES,REGISTRYDUMP'
             property 'forge.logging.console.level', 'debug'
 
             mods {
@@ -60,7 +63,7 @@ minecraft {
 
         data {
             workingDirectory project.file('run')
-            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'
+            property 'forge.logging.markers', 'REGISTRIES,REGISTRYDUMP'
             property 'forge.logging.console.level', 'debug'
 
             args '--mod', 'computercraft', '--all', '--output', file('src/generated/resources/'), '--existing', file('src/main/resources/')
@@ -77,11 +80,14 @@ minecraft {
     accessTransformer file('src/main/resources/META-INF/accesstransformer.cfg')
 }
 
-sourceSets.main.resources {
-    srcDir 'src/generated/resources'
+sourceSets {
+    main.resources {
+        srcDir 'src/generated/resources'
+    }
 }
 
 repositories {
+    mavenCentral()
     maven {
         name "SquidDev"
         url "https://squiddev.cc/maven"
@@ -92,6 +98,7 @@ configurations {
     shade
     compile.extendsFrom shade
     deployerJars
+    cctJavadoc
 }
 
 dependencies {
@@ -104,12 +111,18 @@ dependencies {
 
     runtimeOnly fg.deobf("mezz.jei:jei-1.15.2:6.0.0.3")
 
+    compileOnly 'com.google.auto.service:auto-service:1.0-rc7'
+    annotationProcessor 'com.google.auto.service:auto-service:1.0-rc7'
+
     shade 'org.squiddev:Cobalt:0.5.1-SNAPSHOT'
 
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.4.2'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.4.2'
+    testImplementation 'org.hamcrest:hamcrest:2.2'
 
     deployerJars "org.apache.maven.wagon:wagon-ssh:3.0.0"
+
+    cctJavadoc 'cc.tweaked:cct-javadoc:1.1.0'
 }
 
 // Compile tasks
@@ -118,6 +131,24 @@ javadoc {
     include "dan200/computercraft/api/**/*.java"
 }
 
+task luaJavadoc(type: Javadoc) {
+    description "Generates documentation for Java-side Lua functions."
+    group "documentation"
+
+    source = sourceSets.main.allJava
+    destinationDir = file("doc/javadoc")
+    classpath = sourceSets.main.compileClasspath
+
+    options.docletpath = configurations.cctJavadoc.files as List
+    options.doclet = "cc.tweaked.javadoc.LuaDoclet"
+
+    // Attempt to run under Java 11 (any Java >= 9 will work though).
+    if(System.getProperty("java.version").startsWith("1.")
+        && (System.getenv("JAVA_HOME_11_X64") != null || project.hasProperty("java11Home"))) {
+        executable = "${System.getenv("JAVA_HOME_11_X64") ?: project.property("java11Home")}/bin/javadoc"
+    }
+}
+
 jar {
     dependsOn javadoc
 
@@ -144,8 +175,6 @@ jar {
     }
 }
 
-
-
 import java.nio.charset.StandardCharsets
 import java.nio.file.*
 import java.util.zip.*
@@ -200,8 +229,6 @@ task proguardMove(dependsOn: proguard) {
     }
 }
 
-
-
 processResources {
     inputs.property "version", mod_version
     inputs.property "mcversion", mc_version
@@ -288,6 +315,15 @@ test {
     }
 }
 
+jacocoTestReport {
+    reports {
+        xml.enabled true
+        html.enabled true
+    }
+}
+
+check.dependsOn jacocoTestReport
+
 license {
     mapping("java", "SLASHSTAR_STYLE")
     strictCheck true
@@ -373,7 +409,7 @@ curseforge {
     apiKey = project.hasProperty('curseForgeApiKey') ? project.curseForgeApiKey : ''
     project {
         id = '282001'
-        releaseType = 'alpha'
+        releaseType = 'release'
         changelog = "Release notes can be found on the GitHub repository (https://github.com/SquidDev-CC/CC-Tweaked/releases/tag/v${mc_version}-${mod_version})."
 
         relations {
@@ -451,7 +487,7 @@ githubRelease {
             .takeWhile { it != 'Type "help changelog" to see the full version history.' }
             .join("\n").trim()
     }
-    prerelease true
+    prerelease false
 }
 
 def uploadTasks = ["uploadArchives", "curseforge", "githubRelease"]

config/checkstyle/checkstyle.xml

@@ -114,11 +114,11 @@
         </module>
         <module name="ParameterName" />
         <module name="StaticVariableName">
-            <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
             <property name="applyToPrivate" value="false" />
         </module>
         <module name="StaticVariableName">
-            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z_]+)?$" />
             <property name="applyToPrivate" value="true" />
         </module>
         <module name="TypeName" />

config/checkstyle/suppressions.xml

@@ -9,4 +9,7 @@
 
     <!-- Do not check for missing package Javadoc. -->
     <suppress checks="JavadocStyle" files=".*[\\/]package-info.java" />
+
+    <!-- The commands API is documented in Lua. -->
+    <suppress checks="SummaryJavadocCheck" files=".*[\\/]CommandAPI.java" />
 </suppressions>

doc/stub/commands.lua

@@ -1,6 +0,0 @@
-function exec(command) end
-function execAsync(commad) end
-function list() end
-function getBlockPosition() end
-function getBlockInfos(min_x, min_y, min_z, max_x, max_y, max_z) end
-function getBlockInfo(x, y, z) end

doc/stub/fs.lua

@@ -2,41 +2,33 @@
 --
 -- @module fs
 
-function list(path) end
-function combine(base, child) end
-function getName(path) end
-function getSize(path) end
-function exists(path) end
-function isDir(path) end
-function isReadOnly(path) end
-function makeDir(path) end
-function move(from, to) end
-function copy(from, to) end
-function delete(path) end
-function open(path, mode) end
-function getDrive(path) end
-function getFreeSpace(path) end
-function find(pattern) end
-function getDir(path) end
-
---- A file handle which can be read from.
+--- Returns true if a path is mounted to the parent filesystem.
 --
--- @type ReadHandle
--- @see fs.open
-local ReadHandle = {}
-function ReadHandle.read(count) end
-function ReadHandle.readAll() end
-function ReadHandle.readLine(with_trailing) end
-function ReadHandle.seek(whence, offset) end
-function ReadHandle.close() end
-
---- A file handle which can be written to.
+-- The root filesystem "/" is considered a mount, along with disk folders and
+-- the rom folder. Other programs (such as network shares) can exstend this to
+-- make other mount types by correctly assigning their return value for getDrive.
 --
--- @type WriteHandle
--- @see fs.open
-local WriteHandle = {}
-function WriteHandle.write(text) end
-function WriteHandle.writeLine(text) end
-function WriteHandle.flush(text) end
-function WriteHandle.seek(whence, offset) end
-function WriteHandle.close() end
+-- @tparam string path The path to check.
+-- @treturn boolean If the path is mounted, rather than a normal file/folder.
+-- @throws If the path does not exist.
+-- @see getDrive
+function isDriveRoot(path) end
+
+--[[- Provides completion for a file or directory name, suitable for use with
+@{read}.
+
+When a directory is a possible candidate for completion, two entries are
+included - one with a trailing slash (indicating that entries within this
+directory exist) and one without it (meaning this entry is an immediate
+completion candidate). `include_dirs` can be set to @{false} to only include
+those with a trailing slash.
+
+@tparam string path The path to complete.
+@tparam string location The location where paths are resolved from.
+@tparam[opt] boolean include_files When @{false}, only directories will be
+included in the returned list.
+@tparam[opt] boolean include_dirs When @{false}, "raw" directories will not be
+included in the returned list.
+@treturn { string... } A list of possible completion candidates.
+]]
+function complete(path, location, include_files, include_dirs) end

doc/stub/http.lua

@@ -93,47 +93,6 @@ function get(...) end
 -- @treturn Response|nil The failing http response, if available.
 function post(...) end
 
---- A http response. This acts very much like a @{fs.ReadHandle|file}, though
--- provides some http specific methods.
---
--- #### `http_success` event
--- #### `http_failure` event
---
--- @type Response
--- @see http.request On how to make a http request.
-local Response = {}
-
---- Returns the response code and response message returned by the server
---
--- @treturn number The response code (i.e. 200)
--- @treturn string The response message (i.e. "OK")
-function Response.getResponseCode() end
-
---- Get a table containing the response's headers, in a format similar to that
--- required by @{http.request}. If multiple headers are sent with the same
--- name, they will be combined with a comma.
---
--- @treturn { [string]=string } The response's headers.
--- Make a request to [example.computercraft.cc](https://example.computercraft.cc),
--- and print the returned headers.
--- ```lua
--- local request = http.get("https://example.computercraft.cc")
--- print(textutils.serialize(request.getResponseHeaders()))
--- -- => {
--- --   [ "Content-Type" ] = "text/plain; charset=utf8",
--- --   [ "content-length" ] = 17,
--- --   ...
--- -- }
--- request.close()
--- ```
-function Response.getResponseHeaders() end
-
-function Response.read(count) end
-function Response.readAll() end
-function Response.readLine(with_trailing) end
-function Response.seek(whence, offset) end
-function Response.close() end
-
 --- Asynchronously determine whether a URL can be requested.
 --
 -- If this returns `true`, one should also listen for [`http_check`
@@ -198,32 +157,3 @@ function websocket(url, headers) end
 -- @tparam[opt] { [string] = string } headers Additional headers to send as part
 -- of the initial websocket connection.
 function websocketAsync(url, headers) end
-
---- A websocket, which can be used to send an receive messages with a web
--- server.
---
--- @type Websocket
--- @see http.websocket On how to open a websocket.
-local Websocket = {}
-
---- Send a websocket message to the connected server.
---
--- @tparam string message The message to send.
--- @tparam[opt] boolean binary Whether this message should be treated as a
--- binary string, rather than encoded text.
--- @throws If the websocket has been closed.
-function Websocket.send(message, binary) end
-
---- Wait for a message from the server.
---
--- @tparam[opt] number timeout The number of seconds to wait if no message is
--- received.
--- @treturn[1] string The received message.
--- @treturn boolean If this was a binary message.
--- @treturn[2] nil If the websocket was closed while waiting, or if we timed out.
--- @throws If the websocket has been closed.
-function Websocket.receive(timeout) end
-
---- Close this websocket. This will terminate the connection, meaning messages
--- can no longer be sent or received along it.
-function Websocket.close() end

doc/stub/os.lua

@@ -1,17 +1,6 @@
-function queueEvent(event, ...) end
-function startTimer(delay) end
-function setAlarm(time) end
-function shutdown() end
-function reboot() end
-function getComputerID() end
-computerID = getComputerID
-function setComputerLabel(label) end
-function getComputerLabel() end
-computerLabel = getComputerLabel
-function clock() end
-function time(timezone) end
-function day(timezone) end
-function cancelTimer(id) end
-function cancelAlarm(id) end
-function epoch(timezone) end
-function date(format, time) end
+-- Defined in bios.lua
+function loadAPI(path) end
+function pullEvent(filter) end
+function pullEventRaw(filter) end
+function version() end
+function run(env, path, ...) end

doc/stub/redstone.lua

@@ -1,14 +0,0 @@
-function getSides() end
-function setOutput(side, on) end
-function getOutput(side) end
-function getInput(side) end
-function setBundledOutput(side, output) end
-function getBundledOutput(side) end
-function getBundledInput(side) end
-function testBundledInput(side, mask) end
-function setAnalogOutput(side, value) end
-setAnalogueOutput = setAnalogOutput
-function getAnalogOutput(sid) end
-getAnalogueOutput = getAnalogOutput
-function getAnalogInput(side) end
-getAnalogueInput = getAnaloguInput

doc/stub/term.lua

@@ -1,52 +0,0 @@
-function write(text) end
-function scroll(lines) end
-function setCursorPos(x, y) end
-function setCursorBlink(blink) end
-function getCursorPos() end
-function getSize() end
-function clear() end
-function clearLine() end
-function setTextColour(colour) end
-setTextColor = setTextColour
-function setBackgroundColour(colour) end
-setBackgroundColor = setBackgroundColour
-function isColour() end
-isColor = isColour
-function getTextColour() end
-getTextColor = getTextColor
-function getBackgroundColour() end
-getBackgroundColour = getBackgroundColour
-function blit(text, text_colours, background_colours) end
-function setPaletteColour(colour, ...) end
-setPaletteColour = setPaletteColour
-function getPaletteColour(colour, ...) end
-getPaletteColour = getPaletteColour
-function nativePaletteColour(colour) end
-nativePaletteColour = nativePaletteColour
-
---- @type Redirect
-local Redirect = {}
-
-Redirect.write = write
-Redirect.scroll = scroll
-Redirect.setCursorPos = setCursorPos
-Redirect.setCursorBlink = setCursorBlink
-Redirect.getCursorPos = getCursorPos
-Redirect.getSize = getSize
-Redirect.clear = clear
-Redirect.clearLine = clearLine
-Redirect.setTextColour = setTextColour
-Redirect.setTextColor = setTextColor
-Redirect.setBackgroundColour = setBackgroundColour
-Redirect.setBackgroundColor = setBackgroundColor
-Redirect.isColour = isColour
-Redirect.isColor = isColor
-Redirect.getTextColour = getTextColour
-Redirect.getTextColor = getTextColor
-Redirect.getBackgroundColour = getBackgroundColour
-Redirect.getBackgroundColor = getBackgroundColor
-Redirect.blit = blit
-Redirect.setPaletteColour = setPaletteColour
-Redirect.setPaletteColor = setPaletteColor
-Redirect.getPaletteColour = getPaletteColour
-Redirect.getPaletteColor = getPaletteColor

doc/stub/turtle.lua

@@ -1,230 +1 @@
---- Move the turtle forward one block.
--- @treturn boolean Whether the turtle could successfully move.
--- @treturn string|nil The reason the turtle could not move.
-function forward() end
-
---- Move the turtle backwards one block.
--- @treturn boolean Whether the turtle could successfully move.
--- @treturn string|nil The reason the turtle could not move.
-function back() end
-
---- Move the turtle up one block.
--- @treturn boolean Whether the turtle could successfully move.
--- @treturn string|nil The reason the turtle could not move.
-function up() end
-
---- Move the turtle down one block.
--- @treturn boolean Whether the turtle could successfully move.
--- @treturn string|nil The reason the turtle could not move.
-function down() end
-
---- Rotate the turtle 90 degress to the left.
-function turnLeft() end
-
---- Rotate the turtle 90 degress to the right.
-function turnRight() end
-
---- Attempt to break the block in front of the turtle.
---
--- This requires a turtle tool capable of breaking the block. Diamond pickaxes
--- (mining turtles) can break any vanilla block, but other tools (such as axes)
--- are more limited.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether a block was broken.
--- @treturn string|nil The reason no block was broken.
-function dig(side) end
-
---- Attempt to break the block above the turtle. See @{dig} for full details.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether a block was broken.
--- @treturn string|nil The reason no block was broken.
-function digUp(side) end
-
---- Attempt to break the block below the turtle. See @{dig} for full details.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether a block was broken.
--- @treturn string|nil The reason no block was broken.
-function digDown(side) end
-
---- Attack the entity in front of the turtle.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether an entity was attacked.
--- @treturn string|nil The reason nothing was attacked.
-function attack(side) end
-
---- Attack the entity above the turtle.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether an entity was attacked.
--- @treturn string|nil The reason nothing was attacked.
-function attackUp(side) end
-
---- Attack the entity below the turtle.
---
--- @tparam[opt] "left"|"right" side The specific tool to use.
--- @treturn boolean Whether an entity was attacked.
--- @treturn string|nil The reason nothing was attacked.
-function attackDown(side) end
-
---- Place a block or item into the world in front of the turtle.
---
--- @treturn boolean Whether the block could be placed.
--- @treturn string|nil The reason the block was not placed.
-function place() end
-
---- Place a block or item into the world above the turtle.
---
--- @treturn boolean Whether the block could be placed.
--- @treturn string|nil The reason the block was not placed.
-function placeUp() end
-
---- Place a block or item into the world below the turtle.
---
--- @treturn boolean Whether the block could be placed.
--- @treturn string|nil The reason the block was not placed.
-function placeDown() end
-
---- Drop the currently selected stack into the inventory in front of the turtle,
--- or as an item into the world if there is no inventory.
---
--- @tparam[opt] number count The number of items to drop. If not given, the
--- entire stack will be dropped.
--- @treturn boolean Whether items were dropped.
--- @treturn string|nil The reason the no items were dropped.
--- @see select
-function drop(count) end
-
---- Drop the currently selected stack into the inventory above the turtle, or as
--- an item into the world if there is no inventory.
---
--- @tparam[opt] number count The number of items to drop. If not given, the
--- entire stack will be dropped.
--- @treturn boolean Whether items were dropped.
--- @treturn string|nil The reason the no items were dropped.
--- @see select
-function dropUp(count) end
-
---- Drop the currently selected stack into the inventory below the turtle, or as
--- an item into the world if there is no inventory.
---
--- @tparam[opt] number count The number of items to drop. If not given, the
--- entire stack will be dropped.
--- @treturn boolean Whether items were dropped.
--- @treturn string|nil The reason the no items were dropped.
--- @see select
-function dropDown(count) end
-
---- Suck an item from the inventory in front of the turtle, or from an item
--- floating in the world.
---
--- This will pull items into the first acceptable slot, starting at the
--- @{select|currently selected} one.
---
--- @tparam[opt] number count The number of items to suck. If not given, up to a
--- stack of items will be picked up.
--- @treturn boolean Whether items were picked up.
--- @treturn string|nil The reason the no items were picked up.
-function suck(count) end
-
---- Suck an item from the inventory above the turtle, or from an item floating
--- in the world.
---
--- @tparam[opt] number count The number of items to suck. If not given, up to a
--- stack of items will be picked up.
--- @treturn boolean Whether items were picked up.
--- @treturn string|nil The reason the no items were picked up.
-function suckUp(count) end
-
---- Suck an item from the inventory below the turtle, or from an item floating
--- in the world.
---
--- @tparam[opt] number count The number of items to suck. If not given, up to a
--- stack of items will be picked up.
--- @treturn boolean Whether items were picked up.
--- @treturn string|nil The reason the no items were picked up.
-function suckDown(count) end
-
---- Check if there is a solid block in front of the turtle. In this case, solid
--- refers to any non-air or liquid block.
---
--- @treturn boolean If there is a solid block in front.
-function detect() end
-
---- Check if there is a solid block above the turtle.
---
--- @treturn boolean If there is a solid block above.
-function detectUp() end
-
---- Check if there is a solid block below the turtle.
---
--- @treturn boolean If there is a solid block below.
-function detectDown() end
-
-function compare() end
-function compareUp() end
-function compareDown() end
-
-function inspect() end
-function inspectUp() end
-function inspectDown() end
-
-
---- Change the currently selected slot.
---
--- The selected slot is determines what slot actions like @{drop} or
--- @{getItemCount} act on.
---
--- @tparam number slot The slot to select.
--- @see getSelectedSlot
-function select(slot) end
-
---- Get the currently selected slot.
---
--- @treturn number The current slot.
--- @see select
-function getSelectedSlot() end
-
---- Get the number of items in the given slot.
---
--- @tparam[opt] number slot The slot we wish to check. Defaults to the @{turtle.select|selected slot}.
--- @treturn number The number of items in this slot.
-function getItemCount(slot) end
-
---- Get the remaining number of items which may be stored in this stack.
---
--- For instance, if a slot contains 13 blocks of dirt, it has room for another 51.
---
--- @tparam[opt] number slot The slot we wish to check. Defaults to the @{turtle.select|selected slot}.
--- @treturn number The space left in this slot.
-function getItemSpace(slot) end
-
-
---- Get detailed information about the items in the given slot.
---
--- @tparam[opt] number slot The slot to get information about. Defaults to the @{turtle.select|selected slot}.
--- @treturn nil|table Information about the given slot, or @{nil} if it is empty.
--- @usage Print the current slot, assuming it contains 13 dirt.
---
---     print(textutils.serialize(turtle.getItemDetail()))
---     -- => {
---     --    name = "minecraft:dirt",
---     --    damage = 0,
---     --    count = 13,
---     -- }
-function getItemDetail(slot) end
-
-function getFuelLevel() end
-
-function refuel(count) end
-function compareTo(slot) end
-function transferTo(slot, count) end
-
-function getFuelLimit() end
-function equipLeft() end
-function equipRight() end
-
 function craft(limit) end

doc/styles.css

@@ -51,7 +51,12 @@ h4 { font-size: 1.06em; }
 a, a:visited, a:active { font-weight: bold; color: #004080; text-decoration: none; }
 a:hover { text-decoration: underline; }
 
-blockquote { margin-left: 3em; }
+blockquote {
+    padding: 0.3em;
+    margin: 1em 0;
+    background: #f0f0f0;
+    border-left: solid 0.5em #ccc;
+}
 
 /* Stop sublists from having initial vertical space */
 ul ul { margin-top: 0px; }

gradle.properties

@@ -1,7 +1,7 @@
 # Mod properties
-mod_version=1.87.0
+mod_version=1.92.0
 
 # Minecraft properties (update mods.toml when changing)
 mc_version=1.15.2
 forge_version=31.1.41
-mappings_version=20200410-1.15.1
+mappings_version=20200429-1.15.1

illuaminate.sexp

@@ -2,6 +2,7 @@
 
 (sources
   /doc/stub/
+  /doc/javadoc/
   /src/main/resources/*/computercraft/lua/bios.lua
   /src/main/resources/*/computercraft/lua/rom/
   /src/test/resources/test-rom)
@@ -12,8 +13,12 @@
   (index doc/index.md)
   (source-link https://github.com/SquidDev-CC/CC-Tweaked/blob/${commit}/${path}#L${line})
 
+  (module-kinds
+    (peripheral Peripherals))
+
   (library-path
     /doc/stub/
+    /doc/javadoc/
 
     /src/main/resources/*/computercraft/lua/rom/apis
     /src/main/resources/*/computercraft/lua/rom/apis/command
@@ -33,17 +38,27 @@
 
     ;; It's useful to name arguments for documentation, so we allow this. It'd
     ;; be good to find a compromise in the future, but this works for now.
-    -var:unused-arg
+    -var:unused-arg)
 
-    ;; Some APIS (keys, colour and os mainly) are incomplete right now.
-    -var:unresolved-member)
   (lint
     (bracket-spaces
       (call no-space)
       (function-args no-space)
       (parens no-space)
       (table space)
-      (index no-space))))
+      (index no-space))
+
+    ;; colours imports from colors, and we don't handle that right now.
+    ;; keys is entirely dynamic, so we skip it.
+    (dynamic-modules colours keys)
+
+    (globals
+      :max
+      _CC_DEFAULT_SETTINGS
+      _CC_DISABLE_LUA51_FEATURES
+      ;; Ideally we'd pick these up from bios.lua, but illuaminate currently
+      ;; isn't smart enough.
+      sleep write printError read rs)))
 
 ;; We disable the unused global linter in bios.lua and the APIs. In the future
 ;; hopefully we'll get illuaminate to handle this.
@@ -54,31 +69,42 @@
   (lint (allow-toplevel-global true)))
 
 ;; Silence some variable warnings in documentation stubs.
-(at /doc/stub
+(at (/doc/stub/ /doc/javadoc/)
   (linters -var:unused-global)
   (lint (allow-toplevel-global true)))
 
 ;; Suppress warnings for currently undocumented modules.
 (at
-  (/doc/stub/commands.lua
-   /doc/stub/fs.lua
+  (; Java APIs
    /doc/stub/http.lua
    /doc/stub/os.lua
-   /doc/stub/redstone.lua
-   /doc/stub/term.lua
    /doc/stub/turtle.lua
-   /src/main/resources/*/computercraft/lua/rom/apis/command/commands.lua
+   ; Java generated APIs
+   /doc/javadoc/turtle.lua
+   ; Peripherals
+   /doc/javadoc/drive.lua
+   /doc/javadoc/speaker.lua
+   /doc/javadoc/printer.lua
+   ; Lua APIs
    /src/main/resources/*/computercraft/lua/rom/apis/io.lua
-   /src/main/resources/*/computercraft/lua/rom/apis/window.lua
-   /src/main/resources/*/computercraft/lua/rom/modules/main/cc/shell/completion.lua)
+   /src/main/resources/*/computercraft/lua/rom/apis/window.lua)
 
-  (linters -doc:undocumented -doc:undocumented-arg))
+  (linters -doc:undocumented -doc:undocumented-arg -doc:undocumented-return))
 
 ;; These currently rely on unknown references.
 (at
   (/src/main/resources/*/computercraft/lua/rom/apis/textutils.lua
    /src/main/resources/*/computercraft/lua/rom/modules/main/cc/completion.lua
    /src/main/resources/*/computercraft/lua/rom/modules/main/cc/shell/completion.lua
-   /src/main/resources/*/computercraft/lua/rom/programs/advanced/multishell.lua
-   /src/main/resources/*/computercraft/lua/rom/programs/shell.lua)
+   /src/main/resources/*/computercraft/lua/rom/programs/shell.lua
+   /doc/stub/fs.lua)
   (linters -doc:unresolved-reference))
+
+(at /src/test/resources/test-rom
+  ; We should still be able to test deprecated members.
+  (linters -var:deprecated)
+
+  (lint
+    (globals
+      :max sleep write
+      cct_test describe expect howlci fail it pending stub)))

src/generated/resources/data/computercraft/loot_tables/blocks/computer_advanced.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",
@@ -16,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/computer_normal.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",
@@ -16,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/disk_drive.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/monitor_advanced.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/monitor_normal.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/printer.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/speaker.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/turtle_advanced.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",
@@ -16,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/turtle_normal.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",
@@ -16,6 +17,9 @@
             {
               "condition": "computercraft:block_named"
             },
+            {
+              "condition": "computercraft:has_id"
+            },
             {
               "condition": "minecraft:inverted",
               "term": {

src/generated/resources/data/computercraft/loot_tables/blocks/wired_modem_full.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/wireless_modem_advanced.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/blocks/wireless_modem_normal.json

@@ -1,4 +1,5 @@
 {
+  "type": "minecraft:block",
   "pools": [
     {
       "name": "main",

src/generated/resources/data/computercraft/loot_tables/treasure_disk.json

@@ -0,0 +1 @@
+{}

src/main/java/dan200/computercraft/ComputerCraft.java

@@ -6,39 +6,22 @@
 package dan200.computercraft;
 
 import dan200.computercraft.api.turtle.event.TurtleAction;
-import dan200.computercraft.core.apis.http.AddressRule;
+import dan200.computercraft.core.apis.http.options.Action;
+import dan200.computercraft.core.apis.http.options.AddressRule;
+import dan200.computercraft.core.asm.GenericSource;
 import dan200.computercraft.shared.Config;
-import dan200.computercraft.shared.computer.blocks.BlockComputer;
+import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.computer.core.ClientComputerRegistry;
 import dan200.computercraft.shared.computer.core.ServerComputerRegistry;
-import dan200.computercraft.shared.computer.items.ItemComputer;
-import dan200.computercraft.shared.media.items.ItemDisk;
-import dan200.computercraft.shared.media.items.ItemPrintout;
-import dan200.computercraft.shared.media.items.ItemTreasureDisk;
-import dan200.computercraft.shared.peripheral.diskdrive.BlockDiskDrive;
-import dan200.computercraft.shared.peripheral.modem.wired.BlockCable;
-import dan200.computercraft.shared.peripheral.modem.wired.BlockWiredModemFull;
-import dan200.computercraft.shared.peripheral.modem.wired.ItemBlockCable;
-import dan200.computercraft.shared.peripheral.modem.wireless.BlockWirelessModem;
-import dan200.computercraft.shared.peripheral.monitor.BlockMonitor;
 import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer;
-import dan200.computercraft.shared.peripheral.printer.BlockPrinter;
-import dan200.computercraft.shared.peripheral.speaker.BlockSpeaker;
-import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.pocket.peripherals.PocketModem;
 import dan200.computercraft.shared.pocket.peripherals.PocketSpeaker;
-import dan200.computercraft.shared.turtle.blocks.BlockTurtle;
-import dan200.computercraft.shared.turtle.items.ItemTurtle;
 import dan200.computercraft.shared.turtle.upgrades.*;
-import net.minecraft.resources.IReloadableResourceManager;
-import net.minecraft.util.ResourceLocation;
+import dan200.computercraft.shared.util.ServiceUtil;
 import net.minecraftforge.fml.common.Mod;
-import net.minecraftforge.fml.server.ServerLifecycleHooks;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import java.io.IOException;
-import java.io.InputStream;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.List;
@@ -52,12 +35,11 @@ public final class ComputerCraft
 {
     public static final String MOD_ID = "computercraft";
 
-    public static final int DATAFIXER_VERSION = 0;
-
     // Configuration options
     public static final String[] DEFAULT_HTTP_ALLOW = new String[] { "*" };
     public static final String[] DEFAULT_HTTP_DENY = new String[] {
         "127.0.0.0/8",
+        "0.0.0.0/8",
         "10.0.0.0/8",
         "172.16.0.0/12",
         "192.168.0.0/16",
@@ -67,36 +49,39 @@ public final class ComputerCraft
     public static int computerSpaceLimit = 1000 * 1000;
     public static int floppySpaceLimit = 125 * 1000;
     public static int maximumFilesOpen = 128;
-    public static boolean disable_lua51_features = false;
-    public static String default_computer_settings = "";
-    public static boolean debug_enable = true;
-    public static boolean logPeripheralErrors = false;
+    public static boolean disableLua51Features = false;
+    public static String defaultComputerSettings = "";
+    public static boolean debugEnable = true;
+    public static boolean logComputerErrors = true;
+    public static boolean commandRequireCreative = true;
 
-    public static int computer_threads = 1;
+    public static int computerThreads = 1;
     public static long maxMainGlobalTime = TimeUnit.MILLISECONDS.toNanos( 10 );
     public static long maxMainComputerTime = TimeUnit.MILLISECONDS.toNanos( 5 );
 
     public static boolean httpEnabled = true;
     public static boolean httpWebsocketEnabled = true;
     public static List<AddressRule> httpRules = Collections.unmodifiableList( Stream.concat(
-        Stream.of( DEFAULT_HTTP_DENY ).map( x -> AddressRule.parse( x, AddressRule.Action.DENY ) ).filter( Objects::nonNull ),
-        Stream.of( DEFAULT_HTTP_ALLOW ).map( x -> AddressRule.parse( x, AddressRule.Action.ALLOW ) ).filter( Objects::nonNull )
+        Stream.of( DEFAULT_HTTP_DENY )
+            .map( x -> AddressRule.parse( x, Action.DENY.toPartial() ) )
+            .filter( Objects::nonNull ),
+        Stream.of( DEFAULT_HTTP_ALLOW )
+            .map( x -> AddressRule.parse( x, Action.ALLOW.toPartial() ) )
+            .filter( Objects::nonNull )
     ).collect( Collectors.toList() ) );
 
-    public static int httpTimeout = 30000;
     public static int httpMaxRequests = 16;
-    public static long httpMaxDownload = 16 * 1024 * 1024;
-    public static long httpMaxUpload = 4 * 1024 * 1024;
     public static int httpMaxWebsockets = 4;
-    public static int httpMaxWebsocketMessage = 128 * 1024;
 
     public static boolean enableCommandBlock = false;
-    public static int modem_range = 64;
-    public static int modem_highAltitudeRange = 384;
-    public static int modem_rangeDuringStorm = 64;
-    public static int modem_highAltitudeRangeDuringStorm = 384;
+    public static int modemRange = 64;
+    public static int modemHighAltitudeRange = 384;
+    public static int modemRangeDuringStorm = 64;
+    public static int modemHighAltitudeRangeDuringStorm = 384;
     public static int maxNotesPerTick = 8;
     public static MonitorRenderer monitorRenderer = MonitorRenderer.BEST;
+    public static double monitorDistanceSq = 4096;
+    public static long monitorBandwidth = 1_000_000;
 
     public static boolean turtlesNeedFuel = true;
     public static int turtleFuelLimit = 20000;
@@ -105,61 +90,19 @@ public final class ComputerCraft
     public static boolean turtlesCanPush = true;
     public static EnumSet<TurtleAction> turtleDisabledActions = EnumSet.noneOf( TurtleAction.class );
 
-    public static final int terminalWidth_computer = 51;
-    public static final int terminalHeight_computer = 19;
+    public static boolean genericPeripheral = false;
 
-    public static final int terminalWidth_turtle = 39;
-    public static final int terminalHeight_turtle = 13;
+    public static int computerTermWidth = 51;
+    public static int computerTermHeight = 19;
 
-    public static final int terminalWidth_pocketComputer = 26;
-    public static final int terminalHeight_pocketComputer = 20;
+    public static final int turtleTermWidth = 39;
+    public static final int turtleTermHeight = 13;
 
-    // Blocks and Items
-    public static final class Blocks
-    {
-        public static BlockComputer computerNormal;
-        public static BlockComputer computerAdvanced;
-        public static BlockComputer computerCommand;
+    public static int pocketTermWidth = 26;
+    public static int pocketTermHeight = 20;
 
-        public static BlockTurtle turtleNormal;
-        public static BlockTurtle turtleAdvanced;
-
-        public static BlockSpeaker speaker;
-        public static BlockDiskDrive diskDrive;
-        public static BlockPrinter printer;
-
-        public static BlockMonitor monitorNormal;
-        public static BlockMonitor monitorAdvanced;
-
-        public static BlockWirelessModem wirelessModemNormal;
-        public static BlockWirelessModem wirelessModemAdvanced;
-
-        public static BlockWiredModemFull wiredModemFull;
-        public static BlockCable cable;
-    }
-
-    public static final class Items
-    {
-        public static ItemComputer computerNormal;
-        public static ItemComputer computerAdvanced;
-        public static ItemComputer computerCommand;
-
-        public static ItemPocketComputer pocketComputerNormal;
-        public static ItemPocketComputer pocketComputerAdvanced;
-
-        public static ItemTurtle turtleNormal;
-        public static ItemTurtle turtleAdvanced;
-
-        public static ItemDisk disk;
-        public static ItemTreasureDisk treasureDisk;
-
-        public static ItemPrintout printedPage;
-        public static ItemPrintout printedPages;
-        public static ItemPrintout printedBook;
-
-        public static ItemBlockCable.Cable cable;
-        public static ItemBlockCable.WiredModem wiredModem;
-    }
+    public static int monitorWidth = 8;
+    public static int monitorHeight = 6;
 
     public static final class TurtleUpgrades
     {
@@ -191,24 +134,8 @@ public final class ComputerCraft
 
     public ComputerCraft()
     {
-        Config.load();
-    }
-
-    public static String getVersion()
-    {
-        return "${version}";
-    }
-
-    public static InputStream getResourceFile( String domain, String subPath )
-    {
-        IReloadableResourceManager manager = ServerLifecycleHooks.getCurrentServer().getResourceManager();
-        try
-        {
-            return manager.getResource( new ResourceLocation( domain, subPath ) ).getInputStream();
-        }
-        catch( IOException ignored )
-        {
-            return null;
-        }
+        Config.setup();
+        Registry.setup();
+        GenericSource.setup( () -> ServiceUtil.loadServicesForge( GenericSource.class ) );
     }
 }

src/main/java/dan200/computercraft/ComputerCraftAPIImpl.java

@@ -5,7 +5,6 @@
  */
 package dan200.computercraft;
 
-import com.google.common.collect.MapMaker;
 import dan200.computercraft.api.ComputerCraftAPI.IComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
@@ -24,7 +23,6 @@ import dan200.computercraft.core.filesystem.ResourceMount;
 import dan200.computercraft.shared.*;
 import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
 import dan200.computercraft.shared.util.IDAssigner;
-import dan200.computercraft.shared.wired.CapabilityWiredElement;
 import dan200.computercraft.shared.wired.WiredNode;
 import net.minecraft.resources.IReloadableResourceManager;
 import net.minecraft.tileentity.TileEntity;
@@ -34,29 +32,47 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockReader;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.LazyOptional;
+import net.minecraftforge.fml.ModList;
 import net.minecraftforge.fml.server.ServerLifecycleHooks;
 
 import javax.annotation.Nonnull;
 import java.io.File;
-import java.lang.ref.WeakReference;
-import java.util.Map;
+import java.io.IOException;
+import java.io.InputStream;
+
+import static dan200.computercraft.shared.Capabilities.CAPABILITY_WIRED_ELEMENT;
 
 public final class ComputerCraftAPIImpl implements IComputerCraftAPI
 {
     public static final ComputerCraftAPIImpl INSTANCE = new ComputerCraftAPIImpl();
 
+    private String version;
+
     private ComputerCraftAPIImpl()
     {
     }
 
-    private WeakReference<IReloadableResourceManager> currentResources;
-    private final Map<ResourceLocation, ResourceMount> mountCache = new MapMaker().weakValues().concurrencyLevel( 1 ).makeMap();
+    public static InputStream getResourceFile( String domain, String subPath )
+    {
+        IReloadableResourceManager manager = ServerLifecycleHooks.getCurrentServer().getResourceManager();
+        try
+        {
+            return manager.getResource( new ResourceLocation( domain, subPath ) ).getInputStream();
+        }
+        catch( IOException ignored )
+        {
+            return null;
+        }
+    }
 
     @Nonnull
     @Override
     public String getInstalledVersion()
     {
-        return "${version}";
+        if( version != null ) return version;
+        return version = ModList.get().getModContainerById( ComputerCraft.MOD_ID )
+            .map( x -> x.getModInfo().getVersion().toString() )
+            .orElse( "unknown" );
     }
 
     @Override
@@ -147,6 +163,6 @@ public final class ComputerCraftAPIImpl implements IComputerCraftAPI
     public LazyOptional<IWiredElement> getWiredElementAt( @Nonnull IBlockReader world, @Nonnull BlockPos pos, @Nonnull Direction side )
     {
         TileEntity tile = world.getTileEntity( pos );
-        return tile == null ? LazyOptional.empty() : tile.getCapability( CapabilityWiredElement.CAPABILITY, side );
+        return tile == null ? LazyOptional.empty() : tile.getCapability( CAPABILITY_WIRED_ELEMENT, side );
     }
 }

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -43,9 +43,10 @@ public final class ComputerCraftAPI
     }
 
     @Nonnull
+    @Deprecated
     public static String getAPIVersion()
     {
-        return "${version}";
+        return getInstalledVersion();
     }
 
     /**

src/main/java/dan200/computercraft/api/lua/ArgumentHelper.java

@@ -1,334 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.lua;
-
-import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.api.peripheral.IPeripheral;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.util.Map;
-
-/**
- * Provides methods for extracting values and validating Lua arguments, such as those provided to
- * {@link ILuaObject#callMethod(ILuaContext, int, Object[])} or
- * {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}.
- *
- * This provides two sets of functions: the {@code get*} methods, which require an argument to be valid, and
- * {@code opt*}, which accept a default value and return that if the argument was not present or was {@code null}.
- * If the argument is of the wrong type, a suitable error message will be thrown, with a similar format to Lua's own
- * error messages.
- *
- * <h2>Example usage:</h2>
- * <pre>
- * {@code
- * int slot = getInt( args, 0 );
- * int amount = optInt( args, 1, 64 );
- * }
- * </pre>
- */
-public final class ArgumentHelper
-{
-    private ArgumentHelper()
-    {
-    }
-
-    /**
-     * Get a string representation of the given value's type.
-     *
-     * @param value The value whose type we are trying to compute.
-     * @return A string representation of the given value's type, in a similar format to that provided by Lua's
-     * {@code type} function.
-     */
-    @Nonnull
-    public static String getType( @Nullable Object value )
-    {
-        if( value == null ) return "nil";
-        if( value instanceof String ) return "string";
-        if( value instanceof Boolean ) return "boolean";
-        if( value instanceof Number ) return "number";
-        if( value instanceof Map ) return "table";
-        return "userdata";
-    }
-
-    /**
-     * Construct a "bad argument" exception, from an expected type and the actual value provided.
-     *
-     * @param index    The argument number, starting from 0.
-     * @param expected The expected type for this argument.
-     * @param actual   The actual value provided for this argument.
-     * @return The constructed exception, which should be thrown immediately.
-     */
-    @Nonnull
-    public static LuaException badArgumentOf( int index, @Nonnull String expected, @Nullable Object actual )
-    {
-        return badArgument( index, expected, getType( actual ) );
-    }
-
-    /**
-     * Construct a "bad argument" exception, from an expected and actual type.
-     *
-     * @param index    The argument number, starting from 0.
-     * @param expected The expected type for this argument.
-     * @param actual   The provided type for this argument.
-     * @return The constructed exception, which should be thrown immediately.
-     */
-    @Nonnull
-    public static LuaException badArgument( int index, @Nonnull String expected, @Nonnull String actual )
-    {
-        return new LuaException( "bad argument #" + (index + 1) + " (" + expected + " expected, got " + actual + ")" );
-    }
-
-    /**
-     * Get an argument as a double.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a number.
-     * @see #getFiniteDouble(Object[], int) if you require this to be finite (i.e. not infinite or NaN).
-     */
-    public static double getDouble( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "number", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return ((Number) value).doubleValue();
-    }
-
-    /**
-     * Get an argument as an integer.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not an integer.
-     */
-    public static int getInt( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return (int) getLong( args, index );
-    }
-
-    /**
-     * Get an argument as a long.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a long.
-     */
-    public static long getLong( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "number", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return checkFinite( index, (Number) value ).longValue();
-    }
-
-    /**
-     * Get an argument as a finite number (not infinite or NaN).
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not finite.
-     */
-    public static double getFiniteDouble( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        return checkFinite( index, getDouble( args, index ) );
-    }
-
-    /**
-     * Get an argument as a boolean.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a boolean.
-     */
-    public static boolean getBoolean( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "boolean", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Boolean) ) throw badArgumentOf( index, "boolean", value );
-        return (Boolean) value;
-    }
-
-    /**
-     * Get an argument as a string.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a string.
-     */
-    @Nonnull
-    public static String getString( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "string", "nil" );
-        Object value = args[index];
-        if( !(value instanceof String) ) throw badArgumentOf( index, "string", value );
-        return (String) value;
-    }
-
-    /**
-     * Get an argument as a table.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @return The argument's value.
-     * @throws LuaException If the value is not a table.
-     */
-    @Nonnull
-    public static Map<?, ?> getTable( @Nonnull Object[] args, int index ) throws LuaException
-    {
-        if( index >= args.length ) throw badArgument( index, "table", "nil" );
-        Object value = args[index];
-        if( !(value instanceof Map) ) throw badArgumentOf( index, "table", value );
-        return (Map<?, ?>) value;
-    }
-
-    /**
-     * Get an argument as a double.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static double optDouble( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return ((Number) value).doubleValue();
-    }
-
-    /**
-     * Get an argument as an int.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static int optInt( @Nonnull Object[] args, int index, int def ) throws LuaException
-    {
-        return (int) optLong( args, index, def );
-    }
-
-    /**
-     * Get an argument as a long.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a number.
-     */
-    public static long optLong( @Nonnull Object[] args, int index, long def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Number) ) throw badArgumentOf( index, "number", value );
-        return checkFinite( index, (Number) value ).longValue();
-    }
-
-    /**
-     * Get an argument as a finite number (not infinite or NaN).
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not finite.
-     */
-    public static double optFiniteDouble( @Nonnull Object[] args, int index, double def ) throws LuaException
-    {
-        return checkFinite( index, optDouble( args, index, def ) );
-    }
-
-    /**
-     * Get an argument as a boolean.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a boolean.
-     */
-    public static boolean optBoolean( @Nonnull Object[] args, int index, boolean def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Boolean) ) throw badArgumentOf( index, "boolean", value );
-        return (Boolean) value;
-    }
-
-    /**
-     * Get an argument as a string.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a string.
-     */
-    public static String optString( @Nonnull Object[] args, int index, String def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof String) ) throw badArgumentOf( index, "string", value );
-        return (String) value;
-    }
-
-    /**
-     * Get an argument as a table.
-     *
-     * @param args  The arguments to extract from.
-     * @param index The index into the argument array to read from.
-     * @param def   The default value, if this argument is not given.
-     * @return The argument's value, or {@code def} if none was provided.
-     * @throws LuaException If the value is not a table.
-     */
-    public static Map<?, ?> optTable( @Nonnull Object[] args, int index, Map<Object, Object> def ) throws LuaException
-    {
-        Object value = index < args.length ? args[index] : null;
-        if( value == null ) return def;
-        if( !(value instanceof Map) ) throw badArgumentOf( index, "table", value );
-        return (Map<?, ?>) value;
-    }
-
-    private static Number checkFinite( int index, Number value ) throws LuaException
-    {
-        checkFinite( index, value.doubleValue() );
-        return value;
-    }
-
-    private static double checkFinite( int index, double value ) throws LuaException
-    {
-        if( !Double.isFinite( value ) ) throw badArgument( index, "number", getNumericType( value ) );
-        return value;
-    }
-
-    /**
-     * Returns a more detailed representation of this number's type. If this is finite, it will just return "number",
-     * otherwise it returns whether it is infinite or NaN.
-     *
-     * @param value The value to extract the type for.
-     * @return This value's numeric type.
-     */
-    @Nonnull
-    public static String getNumericType( double value )
-    {
-        if( Double.isNaN( value ) ) return "nan";
-        if( value == Double.POSITIVE_INFINITY ) return "inf";
-        if( value == Double.NEGATIVE_INFINITY ) return "-inf";
-        return "number";
-    }
-}

src/main/java/dan200/computercraft/api/lua/IArguments.java

@@ -0,0 +1,407 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Map;
+import java.util.Optional;
+
+import static dan200.computercraft.api.lua.LuaValues.checkFinite;
+
+/**
+ * The arguments passed to a function.
+ */
+public interface IArguments
+{
+    /**
+     * Get the number of arguments passed to this function.
+     *
+     * @return The number of passed arguments.
+     */
+    int count();
+
+    /**
+     * Get the argument at the specific index. The returned value must obey the following conversion rules:
+     *
+     * <ul>
+     *   <li>Lua values of type "string" will be represented by a {@link String}.</li>
+     *   <li>Lua values of type "number" will be represented by a {@link Number}.</li>
+     *   <li>Lua values of type "boolean" will be represented by a {@link Boolean}.</li>
+     *   <li>Lua values of type "table" will be represented by a {@link Map}.</li>
+     *   <li>Lua values of any other type will be represented by a {@code null} value.</li>
+     * </ul>
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@code null} if not present.
+     */
+    @Nullable
+    Object get( int index );
+
+    /**
+     * Drop a number of arguments. The returned arguments instance will access arguments at position {@code i + count},
+     * rather than {@code i}. However, errors will still use the given argument index.
+     *
+     * @param count The number of arguments to drop.
+     * @return The new {@link IArguments} instance.
+     */
+    IArguments drop( int count );
+
+    default Object[] getAll()
+    {
+        Object[] result = new Object[count()];
+        for( int i = 0; i < result.length; i++ ) result[i] = get( i );
+        return result;
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a number.
+     * @see #getFiniteDouble(int) if you require this to be finite (i.e. not infinite or NaN).
+     */
+    default double getDouble( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return ((Number) value).doubleValue();
+    }
+
+    /**
+     * Get an argument as an integer.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not an integer.
+     */
+    default int getInt( int index ) throws LuaException
+    {
+        return (int) getLong( index );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a long.
+     */
+    default long getLong( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return LuaValues.checkFiniteNum( index, (Number) value ).longValue();
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not finite.
+     */
+    default double getFiniteDouble( int index ) throws LuaException
+    {
+        return checkFinite( index, getDouble( index ) );
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default boolean getBoolean( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return (Boolean) value;
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string.
+     */
+    @Nonnull
+    default String getString( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return (String) value;
+    }
+
+    /**
+     * Get a string argument as a byte array.
+     *
+     * @param index The argument number.
+     * @return The argument's value. This is a <em>read only</em> buffer.
+     * @throws LuaException If the value is not a string.
+     */
+    @Nonnull
+    default ByteBuffer getBytes( int index ) throws LuaException
+    {
+        return LuaValues.encode( getString( index ) );
+    }
+
+    /**
+     * Get a string argument as an enum value.
+     *
+     * @param index The argument number.
+     * @param klass The type of enum to parse.
+     * @param <T>   The type of enum to parse.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string or not a valid option for this enum.
+     */
+    @Nonnull
+    default <T extends Enum<T>> T getEnum( int index, Class<T> klass ) throws LuaException
+    {
+        return LuaValues.checkEnum( index, klass, getString( index ) );
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a table.
+     */
+    @Nonnull
+    default Map<?, ?> getTable( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( !(value instanceof Map) ) throw LuaValues.badArgumentOf( index, "table", value );
+        return (Map<?, ?>) value;
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    @Nonnull
+    default Optional<Double> optDouble( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( ((Number) value).doubleValue() );
+    }
+
+    /**
+     * Get an argument as an int.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    @Nonnull
+    default Optional<Integer> optInt( int index ) throws LuaException
+    {
+        return optLong( index ).map( Long::intValue );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a number.
+     */
+    default Optional<Long> optLong( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( LuaValues.checkFiniteNum( index, (Number) value ).longValue() );
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not finite.
+     */
+    default Optional<Double> optFiniteDouble( int index ) throws LuaException
+    {
+        Optional<Double> value = optDouble( index );
+        if( value.isPresent() ) LuaValues.checkFiniteNum( index, value.get() );
+        return value;
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default Optional<Boolean> optBoolean( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return Optional.of( (Boolean) value );
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a string.
+     */
+    default Optional<String> optString( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return Optional.of( (String) value );
+    }
+
+    /**
+     * Get a string argument as a byte array.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present. This is a <em>read only</em> buffer.
+     * @throws LuaException If the value is not a string.
+     */
+    default Optional<ByteBuffer> optBytes( int index ) throws LuaException
+    {
+        return optString( index ).map( LuaValues::encode );
+    }
+
+    /**
+     * Get a string argument as an enum value.
+     *
+     * @param index The argument number.
+     * @param klass The type of enum to parse.
+     * @param <T>   The type of enum to parse.
+     * @return The argument's value.
+     * @throws LuaException If the value is not a string or not a valid option for this enum.
+     */
+    @Nonnull
+    default <T extends Enum<T>> Optional<T> optEnum( int index, Class<T> klass ) throws LuaException
+    {
+        Optional<String> str = optString( index );
+        return str.isPresent() ? Optional.of( LuaValues.checkEnum( index, klass, str.get() ) ) : Optional.empty();
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @return The argument's value, or {@link Optional#empty()} if not present.
+     * @throws LuaException If the value is not a table.
+     */
+    default Optional<Map<?, ?>> optTable( int index ) throws LuaException
+    {
+        Object value = get( index );
+        if( value == null ) return Optional.empty();
+        if( !(value instanceof Map) ) throw LuaValues.badArgumentOf( index, "map", value );
+        return Optional.of( (Map<?, ?>) value );
+    }
+
+    /**
+     * Get an argument as a double.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default double optDouble( int index, double def ) throws LuaException
+    {
+        return optDouble( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as an int.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default int optInt( int index, int def ) throws LuaException
+    {
+        return optInt( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a long.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a number.
+     */
+    default long optLong( int index, long def ) throws LuaException
+    {
+        return optLong( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a finite number (not infinite or NaN).
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not finite.
+     */
+    default double optFiniteDouble( int index, double def ) throws LuaException
+    {
+        return optFiniteDouble( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a boolean.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a boolean.
+     */
+    default boolean optBoolean( int index, boolean def ) throws LuaException
+    {
+        return optBoolean( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a string.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a string.
+     */
+    default String optString( int index, String def ) throws LuaException
+    {
+        return optString( index ).orElse( def );
+    }
+
+    /**
+     * Get an argument as a table.
+     *
+     * @param index The argument number.
+     * @param def   The default value, if this argument is not given.
+     * @return The argument's value, or {@code def} if none was provided.
+     * @throws LuaException If the value is not a table.
+     */
+    default Map<?, ?> optTable( int index, Map<Object, Object> def ) throws LuaException
+    {
+        return optTable( index ).orElse( def );
+    }
+}

src/main/java/dan200/computercraft/api/lua/IDynamicLuaObject.java

@@ -0,0 +1,45 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IDynamicPeripheral;
+
+import javax.annotation.Nonnull;
+
+/**
+ * An interface for representing custom objects returned by peripherals or other Lua objects.
+ *
+ * Generally, one does not need to implement this type - it is sufficient to return an object with some methods
+ * annotated with {@link LuaFunction}. {@link IDynamicLuaObject} is useful when you wish your available methods to
+ * change at runtime.
+ */
+public interface IDynamicLuaObject
+{
+    /**
+     * Get the names of the methods that this object implements. This should not change over the course of the object's
+     * lifetime.
+     *
+     * @return The method names this object provides.
+     * @see IDynamicPeripheral#getMethodNames()
+     */
+    @Nonnull
+    String[] getMethodNames();
+
+    /**
+     * Called when a user calls one of the methods that this object implements.
+     *
+     * @param context   The context of the currently running lua thread. This can be used to wait for events
+     *                  or otherwise yield.
+     * @param method    An integer identifying which method index from {@link #getMethodNames()} the computer wishes
+     *                  to call.
+     * @param arguments The arguments for this method.
+     * @return The result of this function. Either an immediate value ({@link MethodResult#of(Object...)} or an
+     * instruction to yield.
+     * @throws LuaException If the function threw an exception.
+     */
+    @Nonnull
+    MethodResult callMethod( @Nonnull ILuaContext context, int method, @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaAPI.java

@@ -8,7 +8,8 @@ package dan200.computercraft.api.lua;
 import dan200.computercraft.api.ComputerCraftAPI;
 
 /**
- * Represents a {@link ILuaObject} which is stored as a global variable on computer startup.
+ * Represents a Lua object which is stored as a global variable on computer startup. This must either provide
+ * {@link LuaFunction} annotated functions or implement {@link IDynamicLuaObject}.
  *
  * Before implementing this interface, consider alternative methods of providing methods. It is generally preferred
  * to use peripherals to provide functionality to users.
@@ -16,7 +17,7 @@ import dan200.computercraft.api.ComputerCraftAPI;
  * @see ILuaAPIFactory
  * @see ComputerCraftAPI#registerAPIFactory(ILuaAPIFactory)
  */
-public interface ILuaAPI extends ILuaObject
+public interface ILuaAPI
 {
     /**
      * Get the globals this API will be assigned to. This will override any other global, so you should

src/main/java/dan200/computercraft/api/lua/ILuaCallback.java

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A continuation which is called when this coroutine is resumed.
+ *
+ * @see MethodResult#yield(Object[], ILuaCallback)
+ */
+public interface ILuaCallback
+{
+    /**
+     * Resume this coroutine.
+     *
+     * @param args The result of resuming this coroutine. These will have the same form as described in
+     *             {@link LuaFunction}.
+     * @return The result of this continuation. Either the result to return to the callee, or another yield.
+     * @throws LuaException On an error.
+     */
+    @Nonnull
+    MethodResult resume( Object[] args ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaContext.java

@@ -6,99 +6,25 @@
 package dan200.computercraft.api.lua;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
- * An interface passed to peripherals and {@link ILuaObject}s by computers or turtles, providing methods
- * that allow the peripheral call to wait for events before returning, just like in lua. This is very useful if you need
- * to signal work to be performed on the main thread, and don't want to return until the work has been completed.
+ * An interface passed to peripherals and {@link IDynamicLuaObject}s by computers or turtles, providing methods
+ * that allow the peripheral call to interface with the computer.
  */
 public interface ILuaContext
 {
-    /**
-     * Wait for an event to occur on the computer, suspending the thread until it arises. This method is exactly
-     * equivalent to {@code os.pullEvent()} in lua.
-     *
-     * @param filter A specific event to wait for, or null to wait for any event.
-     * @return An object array containing the name of the event that occurred, and any event parameters.
-     * @throws LuaException         If the user presses CTRL+T to terminate the current program while pullEvent() is
-     *                              waiting for an event, a "Terminated" exception will be thrown here.
-     *
-     *                              Do not attempt to catch this exception. You should use {@link #pullEventRaw(String)}
-     *                              should you wish to disable termination.
-     * @throws InterruptedException If the user shuts down or reboots the computer while pullEvent() is waiting for an
-     *                              event, InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     */
-    @Nonnull
-    default Object[] pullEvent( @Nullable String filter ) throws LuaException, InterruptedException
-    {
-        Object[] results = pullEventRaw( filter );
-        if( results.length >= 1 && results[0].equals( "terminate" ) ) throw new LuaException( "Terminated", 0 );
-        return results;
-    }
-
-    /**
-     * The same as {@link #pullEvent(String)}, except "terminated" events are ignored. Only use this if you want to
-     * prevent program termination, which is not recommended. This method is exactly equivalent to
-     * {@code os.pullEventRaw()} in lua.
-     *
-     * @param filter A specific event to wait for, or null to wait for any event.
-     * @return An object array containing the name of the event that occurred, and any event parameters.
-     * @throws InterruptedException If the user shuts down or reboots the computer while pullEventRaw() is waiting for
-     *                              an event, InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #pullEvent(String)
-     */
-    @Nonnull
-    default Object[] pullEventRaw( @Nullable String filter ) throws InterruptedException
-    {
-        return yield( new Object[] { filter } );
-    }
-
-    /**
-     * Yield the current coroutine with some arguments until it is resumed. This method is exactly equivalent to
-     * {@code coroutine.yield()} in lua. Use {@code pullEvent()} if you wish to wait for events.
-     *
-     * @param arguments An object array containing the arguments to pass to coroutine.yield()
-     * @return An object array containing the return values from coroutine.yield()
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #pullEvent(String)
-     */
-    @Nonnull
-    Object[] yield( @Nullable Object[] arguments ) throws InterruptedException;
-
-    /**
-     * Queue a task to be executed on the main server thread at the beginning of next tick, waiting for it to complete.
-     * This should be used when you need to interact with the world in a thread-safe manner.
-     *
-     * Note that the return values of your task are handled as events, meaning more complex objects such as maps or
-     * {@link ILuaObject} will not preserve their identities.
-     *
-     * @param task The task to execute on the main thread.
-     * @return The objects returned by {@code task}.
-     * @throws LuaException         If the task could not be queued, or if the task threw an exception.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     */
-    @Nullable
-    Object[] executeMainThreadTask( @Nonnull ILuaTask task ) throws LuaException, InterruptedException;
-
     /**
      * Queue a task to be executed on the main server thread at the beginning of next tick, but do not wait for it to
      * complete. This should be used when you need to interact with the world in a thread-safe manner but do not care
      * about the result or you wish to run asynchronously.
      *
      * When the task has finished, it will enqueue a {@code task_completed} event, which takes the task id, a success
-     * value and the return values, or an error message if it failed. If you need to wait on this event, it may be
-     * better to use {@link #executeMainThreadTask(ILuaTask)}.
+     * value and the return values, or an error message if it failed.
      *
      * @param task The task to execute on the main thread.
      * @return The "id" of the task. This will be the first argument to the {@code task_completed} event.
      * @throws LuaException If the task could not be queued.
+     * @see LuaFunction#mainThread() To run functions on the main thread and return their results synchronously.
      */
     long issueMainThreadTask( @Nonnull ILuaTask task ) throws LuaException;
 }

src/main/java/dan200/computercraft/api/lua/ILuaFunction.java

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A function, which can be called from Lua. If you need to return a table of functions, it is recommended to use
+ * an object with {@link LuaFunction} methods, or implement {@link IDynamicLuaObject}.
+ *
+ * @see MethodResult#of(Object)
+ */
+@FunctionalInterface
+public interface ILuaFunction
+{
+    /**
+     * Call this function with a series of arguments. Note, this will <em>always</em> be called on the computer thread,
+     * and so its implementation must be thread-safe.
+     *
+     * @param arguments The arguments for this function
+     * @return The result of calling this function.
+     * @throws LuaException Upon Lua errors.
+     */
+    @Nonnull
+    MethodResult call( @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/lua/ILuaObject.java

@@ -1,55 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.lua;
-
-import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.api.peripheral.IPeripheral;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * An interface for representing custom objects returned by {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}
- * calls.
- *
- * Return objects implementing this interface to expose objects with methods to lua.
- */
-public interface ILuaObject
-{
-    /**
-     * Get the names of the methods that this object implements. This works the same as {@link IPeripheral#getMethodNames()}.
-     * See that method for detailed documentation.
-     *
-     * @return The method names this object provides.
-     * @see IPeripheral#getMethodNames()
-     */
-    @Nonnull
-    String[] getMethodNames();
-
-    /**
-     * Called when a user calls one of the methods that this object implements. This works the same as
-     * {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}}. See that method for detailed
-     * documentation.
-     *
-     * @param context   The context of the currently running lua thread. This can be used to wait for events
-     *                  or otherwise yield.
-     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
-     *                  wishes to call. The integer indicates the index into the getMethodNames() table
-     *                  that corresponds to the string passed into peripheral.call()
-     * @param arguments The arguments for this method. See {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}
-     *                  the possible values and conversion rules.
-     * @return An array of objects, representing the values you wish to return to the Lua program.
-     * See {@link IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])} for the valid values and
-     * conversion rules.
-     * @throws LuaException         If the task could not be queued, or if the task threw an exception.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.w
-     * @see IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])
-     */
-    @Nullable
-    Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException;
-}

src/main/java/dan200/computercraft/api/lua/ILuaTask.java

@@ -8,11 +8,10 @@ package dan200.computercraft.api.lua;
 import javax.annotation.Nullable;
 
 /**
- * A task which can be executed via {@link ILuaContext#executeMainThreadTask(ILuaTask)} or
- * {@link ILuaContext#issueMainThreadTask(ILuaTask)}. This will be run on the main thread, at the beginning of the
+ * A task which can be executed via {@link ILuaContext#issueMainThreadTask(ILuaTask)} This will be run on the main
+ * thread, at the beginning of the
  * next tick.
  *
- * @see ILuaContext#executeMainThreadTask(ILuaTask)
  * @see ILuaContext#issueMainThreadTask(ILuaTask)
  */
 @FunctionalInterface
@@ -21,8 +20,7 @@ public interface ILuaTask
     /**
      * Execute this task.
      *
-     * @return The arguments to add to the {@code task_completed} event. These will be returned by
-     * {@link ILuaContext#executeMainThreadTask(ILuaTask)}.
+     * @return The arguments to add to the {@code task_completed} event.
      * @throws LuaException If you throw any exception from this function, a lua error will be raised with the
      *                      same message as your exception. Use this to throw appropriate errors if the wrong
      *                      arguments are supplied to your method.

src/main/java/dan200/computercraft/api/lua/LuaException.java

@@ -13,24 +13,33 @@ import javax.annotation.Nullable;
 public class LuaException extends Exception
 {
     private static final long serialVersionUID = -6136063076818512651L;
+    private final boolean hasLevel;
     private final int level;
 
-    public LuaException()
-    {
-        this( "error", 1 );
-    }
-
     public LuaException( @Nullable String message )
     {
-        this( message, 1 );
+        super( message );
+        this.hasLevel = false;
+        this.level = 1;
     }
 
     public LuaException( @Nullable String message, int level )
     {
         super( message );
+        this.hasLevel = true;
         this.level = level;
     }
 
+    /**
+     * Whether a level was explicitly specified when constructing. This is used to determine
+     *
+     * @return Whether this has an explicit level.
+     */
+    public boolean hasLevel()
+    {
+        return hasLevel;
+    }
+
     /**
      * The level this error is raised at. Level 1 is the function's caller, level 2 is that function's caller, and so
      * on.

src/main/java/dan200/computercraft/api/lua/LuaFunction.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.peripheral.IPeripheral;
+
+import java.lang.annotation.*;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Used to mark a Java function which is callable from Lua.
+ *
+ * Methods annotated with {@link LuaFunction} must be public final instance methods. They can have any number of
+ * parameters, but they must be of the following types:
+ *
+ * <ul>
+ *   <li>{@link ILuaContext} (and {@link IComputerAccess} if on a {@link IPeripheral})</li>
+ *   <li>{@link IArguments}: The arguments supplied to this function.</li>
+ *   <li>
+ *     Alternatively, one may specify the desired arguments as normal parameters and the argument parsing code will
+ *     be generated automatically.
+ *
+ *     Each parameter must be one of the given types supported by {@link IArguments} (for instance, {@link int} or
+ *     {@link Map}). Optional values are supported by accepting a parameter of type {@link Optional}.
+ *   </li>
+ * </ul>
+ *
+ * This function may return {@link MethodResult}. However, if you simply return a value (rather than having to yield),
+ * you may return {@code void}, a single value (either an object or a primitive like {@code int}) or array of objects.
+ * These will be treated the same as {@link MethodResult#of()}, {@link MethodResult#of(Object)} and
+ * {@link MethodResult#of(Object...)}.
+ */
+@Documented
+@Retention( RetentionPolicy.RUNTIME )
+@Target( ElementType.METHOD )
+public @interface LuaFunction
+{
+    /**
+     * Explicitly specify the method names of this function. If not given, it uses the name of the annotated method.
+     *
+     * @return This function's name(s).
+     */
+    String[] value() default {};
+
+    /**
+     * Run this function on the main server thread. This should be specified for any method which interacts with
+     * Minecraft in a thread-unsafe manner.
+     *
+     * @return Whether this functi
+     * @see ILuaContext#issueMainThreadTask(ILuaTask)
+     */
+    boolean mainThread() default false;
+}

src/main/java/dan200/computercraft/api/lua/LuaValues.java

@@ -0,0 +1,152 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Map;
+
+/**
+ * Various utility functions for operating with Lua values.
+ *
+ * @see IArguments
+ */
+public final class LuaValues
+{
+    private LuaValues()
+    {
+    }
+
+    /**
+     * Encode a Lua string into a read-only {@link ByteBuffer}.
+     *
+     * @param string The string to encode.
+     * @return The encoded string.
+     */
+    @Nonnull
+    public static ByteBuffer encode( @Nonnull String string )
+    {
+        byte[] chars = new byte[string.length()];
+        for( int i = 0; i < chars.length; i++ )
+        {
+            char c = string.charAt( i );
+            chars[i] = c < 256 ? (byte) c : 63;
+        }
+
+        return ByteBuffer.wrap( chars ).asReadOnlyBuffer();
+    }
+
+    /**
+     * Returns a more detailed representation of this number's type. If this is finite, it will just return "number",
+     * otherwise it returns whether it is infinite or NaN.
+     *
+     * @param value The value to extract the type for.
+     * @return This value's numeric type.
+     */
+    @Nonnull
+    public static String getNumericType( double value )
+    {
+        if( Double.isNaN( value ) ) return "nan";
+        if( value == Double.POSITIVE_INFINITY ) return "inf";
+        if( value == Double.NEGATIVE_INFINITY ) return "-inf";
+        return "number";
+    }
+
+    /**
+     * Get a string representation of the given value's type.
+     *
+     * @param value The value whose type we are trying to compute.
+     * @return A string representation of the given value's type, in a similar format to that provided by Lua's
+     * {@code type} function.
+     */
+    @Nonnull
+    public static String getType( @Nullable Object value )
+    {
+        if( value == null ) return "nil";
+        if( value instanceof String ) return "string";
+        if( value instanceof Boolean ) return "boolean";
+        if( value instanceof Number ) return "number";
+        if( value instanceof Map ) return "table";
+        return "userdata";
+    }
+
+    /**
+     * Construct a "bad argument" exception, from an expected type and the actual value provided.
+     *
+     * @param index    The argument number, starting from 0.
+     * @param expected The expected type for this argument.
+     * @param actual   The actual value provided for this argument.
+     * @return The constructed exception, which should be thrown immediately.
+     */
+    @Nonnull
+    public static LuaException badArgumentOf( int index, @Nonnull String expected, @Nullable Object actual )
+    {
+        return badArgument( index, expected, getType( actual ) );
+    }
+
+    /**
+     * Construct a "bad argument" exception, from an expected and actual type.
+     *
+     * @param index    The argument number, starting from 0.
+     * @param expected The expected type for this argument.
+     * @param actual   The provided type for this argument.
+     * @return The constructed exception, which should be thrown immediately.
+     */
+    @Nonnull
+    public static LuaException badArgument( int index, @Nonnull String expected, @Nonnull String actual )
+    {
+        return new LuaException( "bad argument #" + (index + 1) + " (" + expected + " expected, got " + actual + ")" );
+    }
+
+    /**
+     * Ensure a numeric argument is finite (i.e. not infinite or {@link Double#NaN}.
+     *
+     * @param index The argument index to check.
+     * @param value The value to check.
+     * @return The input {@code value}.
+     * @throws LuaException If this is not a finite number.
+     */
+    public static Number checkFiniteNum( int index, Number value ) throws LuaException
+    {
+        checkFinite( index, value.doubleValue() );
+        return value;
+    }
+
+    /**
+     * Ensure a numeric argument is finite (i.e. not infinite or {@link Double#NaN}.
+     *
+     * @param index The argument index to check.
+     * @param value The value to check.
+     * @return The input {@code value}.
+     * @throws LuaException If this is not a finite number.
+     */
+    public static double checkFinite( int index, double value ) throws LuaException
+    {
+        if( !Double.isFinite( value ) ) throw badArgument( index, "number", getNumericType( value ) );
+        return value;
+    }
+
+    /**
+     * Ensure a string is a valid enum value.
+     *
+     * @param index The argument index to check.
+     * @param klass The class of the enum instance.
+     * @param value The value to extract.
+     * @param <T>   The type of enum we are extracting.
+     * @return The parsed enum value.
+     * @throws LuaException If this is not a known enum value.
+     */
+    public static <T extends Enum<T>> T checkEnum( int index, Class<T> klass, String value ) throws LuaException
+    {
+        for( T possibility : klass.getEnumConstants() )
+        {
+            if( possibility.name().equalsIgnoreCase( value ) ) return possibility;
+        }
+
+        throw new LuaException( "bad argument #" + (index + 1) + " (unknown option " + value + ")" );
+    }
+}

src/main/java/dan200/computercraft/api/lua/MethodResult.java

@@ -0,0 +1,170 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.peripheral.IComputerAccess;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.nio.ByteBuffer;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * The result of invoking a Lua method.
+ *
+ * Method results either return a value immediately ({@link #of(Object...)} or yield control to the parent coroutine.
+ * When the current coroutine is resumed, we invoke the provided {@link ILuaCallback#resume(Object[])} callback.
+ */
+public final class MethodResult
+{
+    private static final MethodResult empty = new MethodResult( null, null );
+
+    private final Object[] result;
+    private final ILuaCallback callback;
+    private final int adjust;
+
+    private MethodResult( Object[] arguments, ILuaCallback callback )
+    {
+        this.result = arguments;
+        this.callback = callback;
+        this.adjust = 0;
+    }
+
+    private MethodResult( Object[] arguments, ILuaCallback callback, int adjust )
+    {
+        this.result = arguments;
+        this.callback = callback;
+        this.adjust = adjust;
+    }
+
+    /**
+     * Return no values immediately.
+     *
+     * @return A method result which returns immediately with no values.
+     */
+    @Nonnull
+    public static MethodResult of()
+    {
+        return empty;
+    }
+
+    /**
+     * Return a single value immediately.
+     *
+     * Integers, doubles, floats, strings, booleans, {@link Map}, {@link Collection}s, arrays and {@code null} will be
+     * converted to their corresponding Lua type. {@code byte[]} and {@link ByteBuffer} will be treated as binary
+     * strings. {@link ILuaFunction} will be treated as a function.
+     *
+     * In order to provide a custom object with methods, one may return a {@link IDynamicLuaObject}, or an arbitrary
+     * class with {@link LuaFunction} annotations. Anything else will be converted to {@code nil}.
+     *
+     * @param value The value to return to the calling Lua function.
+     * @return A method result which returns immediately with the given value.
+     */
+    @Nonnull
+    public static MethodResult of( @Nullable Object value )
+    {
+        return new MethodResult( new Object[] { value }, null );
+    }
+
+    /**
+     * Return any number of values immediately.
+     *
+     * @param values The values to return. See {@link #of(Object)} for acceptable values.
+     * @return A method result which returns immediately with the given values.
+     */
+    @Nonnull
+    public static MethodResult of( @Nullable Object... values )
+    {
+        return values == null || values.length == 0 ? empty : new MethodResult( values, null );
+    }
+
+    /**
+     * Wait for an event to occur on the computer, suspending the thread until it arises. This method is exactly
+     * equivalent to {@code os.pullEvent()} in lua.
+     *
+     * @param filter   A specific event to wait for, or null to wait for any event.
+     * @param callback The callback to resume with the name of the event that occurred, and any event parameters.
+     * @return The method result which represents this yield.
+     * @see IComputerAccess#queueEvent(String, Object[])
+     */
+    @Nonnull
+    public static MethodResult pullEvent( @Nullable String filter, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( new Object[] { filter }, results -> {
+            if( results.length >= 1 && results[0].equals( "terminate" ) ) throw new LuaException( "Terminated", 0 );
+            return callback.resume( results );
+        } );
+    }
+
+    /**
+     * The same as {@link #pullEvent(String, ILuaCallback)}, except "terminated" events are ignored. Only use this if
+     * you want to prevent program termination, which is not recommended. This method is exactly equivalent to
+     * {@code os.pullEventRaw()} in Lua.
+     *
+     * @param filter   A specific event to wait for, or null to wait for any event.
+     * @param callback The callback to resume with the name of the event that occurred, and any event parameters.
+     * @return The method result which represents this yield.
+     * @see #pullEvent(String, ILuaCallback)
+     */
+    @Nonnull
+    public static MethodResult pullEventRaw( @Nullable String filter, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( new Object[] { filter }, callback );
+    }
+
+    /**
+     * Yield the current coroutine with some arguments until it is resumed. This method is exactly equivalent to
+     * {@code coroutine.yield()} in lua. Use {@code pullEvent()} if you wish to wait for events.
+     *
+     * @param arguments An object array containing the arguments to pass to coroutine.yield()
+     * @param callback  The callback to resume with an array containing the return values from coroutine.yield()
+     * @return The method result which represents this yield.
+     * @see #pullEvent(String, ILuaCallback)
+     */
+    @Nonnull
+    public static MethodResult yield( @Nullable Object[] arguments, @Nonnull ILuaCallback callback )
+    {
+        Objects.requireNonNull( callback, "callback cannot be null" );
+        return new MethodResult( arguments, callback );
+    }
+
+    @Nullable
+    public Object[] getResult()
+    {
+        return result;
+    }
+
+    @Nullable
+    public ILuaCallback getCallback()
+    {
+        return callback;
+    }
+
+    public int getErrorAdjust()
+    {
+        return adjust;
+    }
+
+    /**
+     * Increase the Lua error by a specific amount. One should never need to use this function - it largely exists for
+     * some CC internal code.
+     *
+     * @param adjust The amount to increase the level by.
+     * @return The new {@link MethodResult} with an adjusted error. This has no effect on immediate results.
+     */
+    @Nonnull
+    public MethodResult adjustError( int adjust )
+    {
+        if( adjust < 0 ) throw new IllegalArgumentException( "cannot adjust by a negative amount" );
+        if( adjust == 0 || callback == null ) return this;
+        return new MethodResult( result, callback, this.adjust + adjust );
+    }
+}

src/main/java/dan200/computercraft/api/lua/ObjectArguments.java

@@ -0,0 +1,66 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.lua;
+
+import javax.annotation.Nullable;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * An implementation of {@link IArguments} which wraps an array of {@link Object}.
+ */
+public final class ObjectArguments implements IArguments
+{
+    private static final IArguments EMPTY = new ObjectArguments();
+    private final List<Object> args;
+
+    @Deprecated
+    @SuppressWarnings( "unused" )
+    public ObjectArguments( IArguments arguments )
+    {
+        throw new IllegalStateException();
+    }
+
+    public ObjectArguments( Object... args )
+    {
+        this.args = Arrays.asList( args );
+    }
+
+    public ObjectArguments( List<Object> args )
+    {
+        this.args = Objects.requireNonNull( args );
+    }
+
+    @Override
+    public int count()
+    {
+        return args.size();
+    }
+
+    @Override
+    public IArguments drop( int count )
+    {
+        if( count < 0 ) throw new IllegalStateException( "count cannot be negative" );
+        if( count == 0 ) return this;
+        if( count >= args.size() ) return EMPTY;
+
+        return new ObjectArguments( args.subList( count, args.size() ) );
+    }
+
+    @Nullable
+    @Override
+    public Object get( int index )
+    {
+        return index >= args.size() ? null : args.get( index );
+    }
+
+    @Override
+    public Object[] getAll()
+    {
+        return args.toArray();
+    }
+}

src/main/java/dan200/computercraft/api/peripheral/IComputerAccess.java

@@ -8,8 +8,10 @@ package dan200.computercraft.api.peripheral;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaCallback;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.ILuaTask;
+import dan200.computercraft.api.lua.MethodResult;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
@@ -146,9 +148,9 @@ public interface IComputerAccess
      *
      *                  You may supply {@code null} to indicate that no arguments are to be supplied.
      * @throws NotAttachedException If the peripheral has been detached.
-     * @see IPeripheral#callMethod
+     * @see MethodResult#pullEvent(String, ILuaCallback)
      */
-    void queueEvent( @Nonnull String event, @Nullable Object[] arguments );
+    void queueEvent( @Nonnull String event, @Nullable Object... arguments );
 
     /**
      * Get a string, unique to the computer, by which the computer refers to this peripheral.

src/main/java/dan200/computercraft/api/peripheral/IDynamicPeripheral.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.peripheral;
+
+import dan200.computercraft.api.lua.*;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A peripheral whose methods are not known at runtime.
+ *
+ * This behaves similarly to {@link IDynamicLuaObject}, though also accepting the current {@link IComputerAccess}.
+ * Generally one may use {@link LuaFunction} instead of implementing this interface.
+ */
+public interface IDynamicPeripheral extends IPeripheral
+{
+    /**
+     * Should return an array of strings that identify the methods that this peripheral exposes to Lua. This will be
+     * called once before each attachment, and should not change when called multiple times.
+     *
+     * @return An array of strings representing method names.
+     * @see #callMethod
+     */
+    @Nonnull
+    String[] getMethodNames();
+
+    /**
+     * This is called when a lua program on an attached computer calls {@code peripheral.call()} with
+     * one of the methods exposed by {@link #getMethodNames()}.
+     *
+     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe when interacting
+     * with Minecraft objects.
+     *
+     * @param computer  The interface to the computer that is making the call. Remember that multiple
+     *                  computers can be attached to a peripheral at once.
+     * @param context   The context of the currently running lua thread. This can be used to wait for events
+     *                  or otherwise yield.
+     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
+     *                  wishes to call. The integer indicates the index into the getMethodNames() table
+     *                  that corresponds to the string passed into peripheral.call()
+     * @param arguments The arguments for this method.
+     * @return A {@link MethodResult} containing the values to return or the action to perform.
+     * @throws LuaException If you throw any exception from this function, a lua error will be raised with the
+     *                      same message as your exception. Use this to throw appropriate errors if the wrong
+     *                      arguments are supplied to your method.
+     * @see #getMethodNames()
+     */
+    @Nonnull
+    MethodResult callMethod( @Nonnull IComputerAccess computer, @Nonnull ILuaContext context, int method, @Nonnull IArguments arguments ) throws LuaException;
+}

src/main/java/dan200/computercraft/api/peripheral/IPeripheral.java

@@ -5,15 +5,20 @@
  */
 package dan200.computercraft.api.peripheral;
 
-import dan200.computercraft.api.lua.ArgumentHelper;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import net.minecraftforge.common.capabilities.Capability;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 /**
- * The interface that defines a peripheral. See {@link IPeripheralProvider} for how to associate blocks with peripherals.
+ * The interface that defines a peripheral.
+ *
+ * In order to expose a peripheral for your block or tile entity, you may either attach a {@link Capability}, or
+ * register a {@link IPeripheralProvider}. This <em>cannot</em> be implemented {@link IPeripheral} directly on the tile.
+ *
+ * Peripherals should provide a series of methods to the user, either using {@link LuaFunction} or by implementing
+ * {@link IDynamicPeripheral}.
  */
 public interface IPeripheral
 {
@@ -26,57 +31,6 @@ public interface IPeripheral
     @Nonnull
     String getType();
 
-    /**
-     * Should return an array of strings that identify the methods that this
-     * peripheral exposes to Lua. This will be called once before each attachment,
-     * and should not change when called multiple times.
-     *
-     * @return An array of strings representing method names.
-     * @see #callMethod
-     */
-    @Nonnull
-    String[] getMethodNames();
-
-    /**
-     * This is called when a lua program on an attached computer calls {@code peripheral.call()} with
-     * one of the methods exposed by {@link #getMethodNames()}.
-     *
-     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe when interacting
-     * with Minecraft objects.
-     *
-     * @param computer  The interface to the computer that is making the call. Remember that multiple
-     *                  computers can be attached to a peripheral at once.
-     * @param context   The context of the currently running lua thread. This can be used to wait for events
-     *                  or otherwise yield.
-     * @param method    An integer identifying which of the methods from getMethodNames() the computercraft
-     *                  wishes to call. The integer indicates the index into the getMethodNames() table
-     *                  that corresponds to the string passed into peripheral.call()
-     * @param arguments An array of objects, representing the arguments passed into {@code peripheral.call()}.<br>
-     *                  Lua values of type "string" will be represented by Object type String.<br>
-     *                  Lua values of type "number" will be represented by Object type Double.<br>
-     *                  Lua values of type "boolean" will be represented by Object type Boolean.<br>
-     *                  Lua values of type "table" will be represented by Object type Map.<br>
-     *                  Lua values of any other type will be represented by a null object.<br>
-     *                  This array will be empty if no arguments are passed.
-     *
-     *                  It is recommended you use {@link ArgumentHelper} in order to validate and process arguments.
-     * @return An array of objects, representing values you wish to return to the lua program. Integers, Doubles, Floats,
-     * Strings, Booleans, Maps, ILuaObject and null be converted to their corresponding lua type. All other types will
-     * be converted to nil.
-     *
-     * You may return null to indicate no values should be returned.
-     * @throws LuaException         If you throw any exception from this function, a lua error will be raised with the
-     *                              same message as your exception. Use this to throw appropriate errors if the wrong
-     *                              arguments are supplied to your method.
-     * @throws InterruptedException If the user shuts down or reboots the computer the coroutine is suspended,
-     *                              InterruptedException will be thrown. This exception must not be caught or
-     *                              intercepted, or the computer will leak memory and end up in a broken state.
-     * @see #getMethodNames
-     * @see ArgumentHelper
-     */
-    @Nullable
-    Object[] callMethod( @Nonnull IComputerAccess computer, @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException;
-
     /**
      * Is called when when a computer is attaching to the peripheral.
      *
@@ -126,10 +80,10 @@ public interface IPeripheral
      *
      * @return The object this peripheral targets
      */
-    @Nonnull
+    @Nullable
     default Object getTarget()
     {
-        return this;
+        return null;
     }
 
     /**

src/main/java/dan200/computercraft/api/peripheral/IPeripheralProvider.java

@@ -9,14 +9,15 @@ import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.Direction;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
+import net.minecraftforge.common.util.LazyOptional;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
  * This interface is used to create peripheral implementations for blocks.
  *
- * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively implement {@link IPeripheralTile}.
+ * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively expose the {@link IPeripheral}
+ * capability.
  *
  * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
  */
@@ -29,9 +30,9 @@ public interface IPeripheralProvider
      * @param world The world the block is in.
      * @param pos   The position the block is at.
      * @param side  The side to get the peripheral from.
-     * @return A peripheral, or {@code null} if there is not a peripheral here you'd like to handle.
+     * @return A peripheral, or {@link LazyOptional#empty()} if there is not a peripheral here you'd like to handle.
      * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
      */
-    @Nullable
-    IPeripheral getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
+    @Nonnull
+    LazyOptional<IPeripheral> getPeripheral( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull Direction side );
 }

src/main/java/dan200/computercraft/api/peripheral/IPeripheralTile.java

@@ -1,32 +0,0 @@
-/*
- * This file is part of the public ComputerCraft API - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2020. This API may be redistributed unmodified and in full only.
- * For help using the API, and posting your mods, visit the forums at computercraft.info.
- */
-package dan200.computercraft.api.peripheral;
-
-import net.minecraft.util.Direction;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-/**
- * A {@link net.minecraft.tileentity.TileEntity} which may act as a peripheral.
- *
- * If you need more complex capabilities (such as handling TEs not belonging to your mod), you should use
- * {@link IPeripheralProvider}.
- */
-public interface IPeripheralTile
-{
-    /**
-     * Get the peripheral on the given {@code side}.
-     *
-     * @param side The side to get the peripheral from.
-     * @return A peripheral, or {@code null} if there is not a peripheral here.
-     * @see IPeripheralProvider#getPeripheral(World, BlockPos, Direction)
-     */
-    @Nullable
-    IPeripheral getPeripheral( @Nonnull Direction side );
-}

src/main/java/dan200/computercraft/api/peripheral/NotAttachedException.java

@@ -15,7 +15,7 @@ public class NotAttachedException extends IllegalStateException
 
     public NotAttachedException()
     {
-        super( "You are not attached to this Computer" );
+        super( "You are not attached to this computer" );
     }
 
     public NotAttachedException( String s )

src/main/java/dan200/computercraft/api/pocket/AbstractPocketUpgrade.java

@@ -5,12 +5,15 @@
  */
 package dan200.computercraft.api.pocket;
 
+import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.IItemProvider;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.Util;
+import net.minecraftforge.common.util.NonNullSupplier;
 
 import javax.annotation.Nonnull;
+import java.util.function.Supplier;
 
 /**
  * A base class for {@link IPocketUpgrade}s.
@@ -21,23 +24,48 @@ public abstract class AbstractPocketUpgrade implements IPocketUpgrade
 {
     private final ResourceLocation id;
     private final String adjective;
-    private final ItemStack stack;
+    private final NonNullSupplier<ItemStack> stack;
 
-    protected AbstractPocketUpgrade( ResourceLocation id, String adjective, ItemStack stack )
+    protected AbstractPocketUpgrade( ResourceLocation id, String adjective, NonNullSupplier<ItemStack> stack )
     {
         this.id = id;
         this.adjective = adjective;
         this.stack = stack;
     }
 
+    protected AbstractPocketUpgrade( ResourceLocation id, NonNullSupplier<ItemStack> item )
+    {
+        this( id, Util.makeTranslationKey( "upgrade", id ) + ".adjective", item );
+    }
+
+    protected AbstractPocketUpgrade( ResourceLocation id, String adjective, ItemStack stack )
+    {
+        this( id, adjective, () -> stack );
+    }
+
+    protected AbstractPocketUpgrade( ResourceLocation id, ItemStack stack )
+    {
+        this( id, () -> stack );
+    }
+
     protected AbstractPocketUpgrade( ResourceLocation id, String adjective, IItemProvider item )
     {
-        this( id, adjective, new ItemStack( item ) );
+        this( id, adjective, new CachedStack( () -> item ) );
     }
 
     protected AbstractPocketUpgrade( ResourceLocation id, IItemProvider item )
     {
-        this( id, Util.makeTranslationKey( "upgrade", id ) + ".adjective", new ItemStack( item ) );
+        this( id, new CachedStack( () -> item ) );
+    }
+
+    protected AbstractPocketUpgrade( ResourceLocation id, String adjective, Supplier<? extends IItemProvider> item )
+    {
+        this( id, adjective, new CachedStack( item ) );
+    }
+
+    protected AbstractPocketUpgrade( ResourceLocation id, Supplier<? extends IItemProvider> item )
+    {
+        this( id, new CachedStack( item ) );
     }
 
     @Nonnull
@@ -58,6 +86,32 @@ public abstract class AbstractPocketUpgrade implements IPocketUpgrade
     @Override
     public final ItemStack getCraftingItem()
     {
-        return stack;
+        return stack.get();
+    }
+
+    /**
+     * Caches the construction of an item stack.
+     *
+     * @see dan200.computercraft.api.turtle.AbstractTurtleUpgrade For explanation of this class.
+     */
+    private static final class CachedStack implements NonNullSupplier<ItemStack>
+    {
+        private final Supplier<? extends IItemProvider> provider;
+        private Item item;
+        private ItemStack stack;
+
+        CachedStack( Supplier<? extends IItemProvider> provider )
+        {
+            this.provider = provider;
+        }
+
+        @Nonnull
+        @Override
+        public ItemStack get()
+        {
+            Item item = provider.get().asItem();
+            if( item == this.item && stack != null ) return stack;
+            return stack = new ItemStack( this.item = item );
+        }
     }
 }

src/main/java/dan200/computercraft/api/turtle/AbstractTurtleUpgrade.java

@@ -5,12 +5,15 @@
  */
 package dan200.computercraft.api.turtle;
 
+import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.IItemProvider;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.Util;
+import net.minecraftforge.common.util.NonNullSupplier;
 
 import javax.annotation.Nonnull;
+import java.util.function.Supplier;
 
 /**
  * A base class for {@link ITurtleUpgrade}s.
@@ -22,9 +25,9 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
     private final ResourceLocation id;
     private final TurtleUpgradeType type;
     private final String adjective;
-    private final ItemStack stack;
+    private final NonNullSupplier<ItemStack> stack;
 
-    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, ItemStack stack )
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, NonNullSupplier<ItemStack> stack )
     {
         this.id = id;
         this.type = type;
@@ -32,19 +35,39 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
         this.stack = stack;
     }
 
-    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, IItemProvider item )
-    {
-        this( id, type, adjective, new ItemStack( item ) );
-    }
-
-    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, ItemStack stack )
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, NonNullSupplier<ItemStack> stack )
     {
         this( id, type, Util.makeTranslationKey( "upgrade", id ) + ".adjective", stack );
     }
 
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, ItemStack stack )
+    {
+        this( id, type, adjective, () -> stack );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, ItemStack stack )
+    {
+        this( id, type, () -> stack );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, IItemProvider item )
+    {
+        this( id, type, adjective, new CachedStack( () -> item ) );
+    }
+
     protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, IItemProvider item )
     {
-        this( id, type, new ItemStack( item ) );
+        this( id, type, new CachedStack( () -> item ) );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, String adjective, Supplier<? extends IItemProvider> item )
+    {
+        this( id, type, adjective, new CachedStack( item ) );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, TurtleUpgradeType type, Supplier<? extends IItemProvider> item )
+    {
+        this( id, type, new CachedStack( item ) );
     }
 
     @Nonnull
@@ -72,6 +95,32 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
     @Override
     public final ItemStack getCraftingItem()
     {
-        return stack;
+        return stack.get();
+    }
+
+    /**
+     * A supplier which converts an item into an item stack.
+     *
+     * Constructing item stacks is somewhat expensive due to attaching capabilities. We cache it if given a consistent item.
+     */
+    private static final class CachedStack implements NonNullSupplier<ItemStack>
+    {
+        private final Supplier<? extends IItemProvider> provider;
+        private Item item;
+        private ItemStack stack;
+
+        CachedStack( Supplier<? extends IItemProvider> provider )
+        {
+            this.provider = provider;
+        }
+
+        @Nonnull
+        @Override
+        public ItemStack get()
+        {
+            Item item = provider.get().asItem();
+            if( item == this.item && stack != null ) return stack;
+            return stack = new ItemStack( this.item = item );
+        }
     }
 }

src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -6,8 +6,8 @@
 package dan200.computercraft.api.turtle;
 
 import com.mojang.authlib.GameProfile;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.ILuaCallback;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import net.minecraft.inventory.IInventory;
 import net.minecraft.nbt.CompoundNBT;
@@ -228,21 +228,15 @@ public interface ITurtleAccess
      * be supplied as a parameter to a "turtle_response" event issued to the turtle after the command has completed. Look at the
      * lua source code for "rom/apis/turtle" for how to build a lua wrapper around this functionality.
      *
-     * @param context The Lua context to pull events from.
      * @param command An object which will execute the custom command when its point in the queue is reached
      * @return The objects the command returned when executed. you should probably return these to the player
      * unchanged if called from a peripheral method.
      * @throws UnsupportedOperationException When attempting to execute a command on the client side.
-     * @throws LuaException                  If the user presses CTRL+T to terminate the current program while {@code executeCommand()} is
-     *                                       waiting for an event, a "Terminated" exception will be thrown here.
-     * @throws InterruptedException          If the user shuts down or reboots the computer while pullEvent() is waiting for an
-     *                                       event, InterruptedException will be thrown. This exception must not be caught or
-     *                                       intercepted, or the computer will leak memory and end up in a broken state.
      * @see ITurtleCommand
-     * @see ILuaContext#pullEvent(String)
+     * @see MethodResult#pullEvent(String, ILuaCallback)
      */
     @Nonnull
-    Object[] executeCommand( @Nonnull ILuaContext context, @Nonnull ITurtleCommand command ) throws LuaException, InterruptedException;
+    MethodResult executeCommand( @Nonnull ITurtleCommand command );
 
     /**
      * Start playing a specific animation. This will prevent other turtle commands from executing until

src/main/java/dan200/computercraft/api/turtle/ITurtleCommand.java

@@ -5,14 +5,12 @@
  */
 package dan200.computercraft.api.turtle;
 
-import dan200.computercraft.api.lua.ILuaContext;
-
 import javax.annotation.Nonnull;
 
 /**
- * An interface for objects executing custom turtle commands, used with {@link ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)}.
+ * An interface for objects executing custom turtle commands, used with {@link ITurtleAccess#executeCommand(ITurtleCommand)}.
  *
- * @see ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)
+ * @see ITurtleAccess#executeCommand(ITurtleCommand)
  */
 @FunctionalInterface
 public interface ITurtleCommand
@@ -25,7 +23,7 @@ public interface ITurtleCommand
      *
      * @param turtle Access to the turtle for whom the command was issued.
      * @return A result, indicating whether this action succeeded or not.
-     * @see ITurtleAccess#executeCommand(ILuaContext, ITurtleCommand)
+     * @see ITurtleAccess#executeCommand(ITurtleCommand)
      * @see TurtleCommandResult#success()
      * @see TurtleCommandResult#failure(String)
      * @see TurtleCommandResult

src/main/java/dan200/computercraft/api/turtle/event/TurtleBlockEvent.java

@@ -5,8 +5,7 @@
  */
 package dan200.computercraft.api.turtle.event;
 
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
@@ -223,7 +222,7 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
          * Add new information to the inspection result. Note this will override fields with the same name.
          *
          * @param newData The data to add. Note all values should be convertible to Lua (see
-         *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
+         *                {@link MethodResult#of(Object)}).
          */
         public void addData( @Nonnull Map<String, ?> newData )
         {

src/main/java/dan200/computercraft/api/turtle/event/TurtleInspectItemEvent.java

@@ -5,8 +5,7 @@
  */
 package dan200.computercraft.api.turtle.event;
 
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.lua.MethodResult;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import net.minecraft.item.ItemStack;
 
@@ -17,8 +16,8 @@ import java.util.Objects;
 /**
  * Fired when a turtle gathers data on an item in its inventory.
  *
- * You may prevent items being inspected, or add additional information to the result. Be aware that this is fired on
- * the computer thread, and so any operations on it must be thread safe.
+ * You may prevent items being inspected, or add additional information to the result. Be aware that this may be fired
+ * on the computer thread, and so any operations on it must be thread safe.
  *
  * @see TurtleAction#INSPECT_ITEM
  */
@@ -26,8 +25,15 @@ public class TurtleInspectItemEvent extends TurtleActionEvent
 {
     private final ItemStack stack;
     private final Map<String, Object> data;
+    private final boolean mainThread;
 
+    @Deprecated
     public TurtleInspectItemEvent( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack stack, @Nonnull Map<String, Object> data )
+    {
+        this( turtle, stack, data, false );
+    }
+
+    public TurtleInspectItemEvent( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack stack, @Nonnull Map<String, Object> data, boolean mainThread )
     {
         super( turtle, TurtleAction.INSPECT_ITEM );
 
@@ -35,6 +41,7 @@ public class TurtleInspectItemEvent extends TurtleActionEvent
         Objects.requireNonNull( data, "data cannot be null" );
         this.stack = stack;
         this.data = data;
+        this.mainThread = mainThread;
     }
 
     /**
@@ -59,11 +66,22 @@ public class TurtleInspectItemEvent extends TurtleActionEvent
         return data;
     }
 
+    /**
+     * If this event is being fired on the server thread. When true, information which relies on server state may be
+     * exposed.
+     *
+     * @return If this is run on the main thread.
+     */
+    public boolean onMainThread()
+    {
+        return mainThread;
+    }
+
     /**
      * Add new information to the inspection result. Note this will override fields with the same name.
      *
      * @param newData The data to add. Note all values should be convertible to Lua (see
-     *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
+     *                {@link MethodResult#of(Object)}).
      */
     public void addData( @Nonnull Map<String, ?> newData )
     {

src/main/java/dan200/computercraft/client/ClientRegistry.java

@@ -7,8 +7,10 @@ package dan200.computercraft.client;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.render.TurtleModelLoader;
+import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.common.IColouredItem;
 import dan200.computercraft.shared.media.items.ItemDisk;
+import dan200.computercraft.shared.media.items.ItemTreasureDisk;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.util.Colour;
 import net.minecraft.client.renderer.model.IBakedModel;
@@ -108,7 +110,7 @@ public final class ClientRegistry
     @SubscribeEvent
     public static void onItemColours( ColorHandlerEvent.Item event )
     {
-        if( ComputerCraft.Items.disk == null || ComputerCraft.Blocks.turtleNormal == null )
+        if( Registry.ModItems.DISK == null || Registry.ModBlocks.TURTLE_NORMAL == null )
         {
             ComputerCraft.log.warn( "Block/item registration has failed. Skipping registration of item colours." );
             return;
@@ -116,7 +118,12 @@ public final class ClientRegistry
 
         event.getItemColors().register(
             ( stack, layer ) -> layer == 1 ? ((ItemDisk) stack.getItem()).getColour( stack ) : 0xFFFFFF,
-            ComputerCraft.Items.disk
+            Registry.ModItems.DISK.get()
+        );
+
+        event.getItemColors().register(
+            ( stack, layer ) -> layer == 1 ? ItemTreasureDisk.getColour( stack ) : 0xFFFFFF,
+            Registry.ModItems.TREASURE_DISK.get()
         );
 
         event.getItemColors().register( ( stack, layer ) -> {
@@ -133,12 +140,12 @@ public final class ClientRegistry
                     return light == -1 ? Colour.BLACK.getHex() : light;
                 }
             }
-        }, ComputerCraft.Items.pocketComputerNormal, ComputerCraft.Items.pocketComputerAdvanced );
+        }, Registry.ModItems.POCKET_COMPUTER_NORMAL.get(), Registry.ModItems.POCKET_COMPUTER_ADVANCED.get() );
 
         // Setup turtle colours
         event.getItemColors().register(
             ( stack, tintIndex ) -> tintIndex == 0 ? ((IColouredItem) stack.getItem()).getColour( stack ) : 0xFFFFFF,
-            ComputerCraft.Blocks.turtleNormal, ComputerCraft.Blocks.turtleAdvanced
+            Registry.ModBlocks.TURTLE_NORMAL.get(), Registry.ModBlocks.TURTLE_ADVANCED.get()
         );
     }
 }

src/main/java/dan200/computercraft/client/gui/FixedWidthFontRenderer.java

@@ -41,15 +41,14 @@ public final class FixedWidthFontRenderer
     {
     }
 
-    private static float toGreyscale( double[] rgb )
+    public static float toGreyscale( double[] rgb )
     {
         return (float) ((rgb[0] + rgb[1] + rgb[2]) / 3);
     }
 
-    private static int getColour( char c )
+    public static int getColour( char c, Colour def )
     {
-        int i = "0123456789abcdef".indexOf( c );
-        return i < 0 ? 0 : 15 - i;
+        return 15 - Terminal.getColour( c, def );
     }
 
     private static void drawChar( Matrix4f transform, IVertexBuilder buffer, float x, float y, int index, float r, float g, float b )
@@ -83,7 +82,7 @@ public final class FixedWidthFontRenderer
 
     private static void drawQuad( Matrix4f transform, IVertexBuilder buffer, float x, float y, float width, float height, Palette palette, boolean greyscale, char colourIndex )
     {
-        double[] colour = palette.getColour( getColour( colourIndex ) );
+        double[] colour = palette.getColour( getColour( colourIndex, Colour.BLACK ) );
         float r, g, b;
         if( greyscale )
         {
@@ -151,7 +150,7 @@ public final class FixedWidthFontRenderer
 
         for( int i = 0; i < text.length(); i++ )
         {
-            double[] colour = palette.getColour( 15 - "0123456789abcdef".indexOf( textColour.charAt( i ) ) );
+            double[] colour = palette.getColour( getColour( textColour.charAt( i ), Colour.BLACK ) );
             float r, g, b;
             if( greyscale )
             {

src/main/java/dan200/computercraft/client/gui/GuiComputer.java

@@ -9,6 +9,7 @@ import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.widgets.WidgetTerminal;
 import dan200.computercraft.client.gui.widgets.WidgetWrapper;
+import dan200.computercraft.client.render.ComputerBorderRenderer;
 import dan200.computercraft.shared.computer.core.ClientComputer;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.inventory.ContainerComputer;
@@ -17,21 +18,18 @@ import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.pocket.inventory.ContainerPocketComputer;
 import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.entity.player.PlayerInventory;
-import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.text.ITextComponent;
 import org.lwjgl.glfw.GLFW;
 
+import static dan200.computercraft.client.render.ComputerBorderRenderer.BORDER;
+import static dan200.computercraft.client.render.ComputerBorderRenderer.MARGIN;
+
 public final class GuiComputer<T extends ContainerComputerBase> extends ContainerScreen<T>
 {
-    public static final ResourceLocation BACKGROUND_NORMAL = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_normal.png" );
-    public static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_advanced.png" );
-    public static final ResourceLocation BACKGROUND_COMMAND = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_command.png" );
-    public static final ResourceLocation BACKGROUND_COLOUR = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_colour.png" );
-
-    private final ComputerFamily m_family;
-    private final ClientComputer m_computer;
-    private final int m_termWidth;
-    private final int m_termHeight;
+    private final ComputerFamily family;
+    private final ClientComputer computer;
+    private final int termWidth;
+    private final int termHeight;
 
     private WidgetTerminal terminal;
     private WidgetWrapper terminalWrapper;
@@ -41,10 +39,10 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
     )
     {
         super( container, player, title );
-        m_family = container.getFamily();
-        m_computer = (ClientComputer) container.getComputer();
-        m_termWidth = termWidth;
-        m_termHeight = termHeight;
+        family = container.getFamily();
+        computer = (ClientComputer) container.getComputer();
+        this.termWidth = termWidth;
+        this.termHeight = termHeight;
         terminal = null;
     }
 
@@ -52,7 +50,7 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
     {
         return new GuiComputer<>(
             container, inventory, component,
-            ComputerCraft.terminalWidth_computer, ComputerCraft.terminalHeight_computer
+            ComputerCraft.computerTermWidth, ComputerCraft.computerTermHeight
         );
     }
 
@@ -60,7 +58,7 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
     {
         return new GuiComputer<>(
             container, inventory, component,
-            ComputerCraft.terminalWidth_pocketComputer, ComputerCraft.terminalHeight_pocketComputer
+            ComputerCraft.pocketTermWidth, ComputerCraft.pocketTermHeight
         );
     }
 
@@ -78,16 +76,16 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
     {
         minecraft.keyboardListener.enableRepeatEvents( true );
 
-        int termPxWidth = m_termWidth * FixedWidthFontRenderer.FONT_WIDTH;
-        int termPxHeight = m_termHeight * FixedWidthFontRenderer.FONT_HEIGHT;
+        int termPxWidth = termWidth * FixedWidthFontRenderer.FONT_WIDTH;
+        int termPxHeight = termHeight * FixedWidthFontRenderer.FONT_HEIGHT;
 
-        xSize = termPxWidth + 4 + 24;
-        ySize = termPxHeight + 4 + 24;
+        xSize = termPxWidth + MARGIN * 2 + BORDER * 2;
+        ySize = termPxHeight + MARGIN * 2 + BORDER * 2;
 
         super.init();
 
-        terminal = new WidgetTerminal( minecraft, () -> m_computer, m_termWidth, m_termHeight, 2, 2, 2, 2 );
-        terminalWrapper = new WidgetWrapper( terminal, 2 + 12 + guiLeft, 2 + 12 + guiTop, termPxWidth, termPxHeight );
+        terminal = new WidgetTerminal( minecraft, () -> computer, termWidth, termHeight, MARGIN, MARGIN, MARGIN, MARGIN );
+        terminalWrapper = new WidgetWrapper( terminal, MARGIN + BORDER + guiLeft, MARGIN + BORDER + guiTop, termPxWidth, termPxHeight );
 
         children.add( terminalWrapper );
         setFocused( terminalWrapper );
@@ -124,41 +122,16 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
     @Override
     public void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
-        // Work out where to draw
-        int startX = terminalWrapper.getX() - 2;
-        int startY = terminalWrapper.getY() - 2;
-        int endX = startX + terminalWrapper.getWidth() + 4;
-        int endY = startY + terminalWrapper.getHeight() + 4;
-
         // Draw terminal
         terminal.draw( terminalWrapper.getX(), terminalWrapper.getY() );
 
         // Draw a border around the terminal
-        RenderSystem.color4f( 1.0f, 1.0f, 1.0f, 1.0f );
-        switch( m_family )
-        {
-            case NORMAL:
-            default:
-                minecraft.getTextureManager().bindTexture( BACKGROUND_NORMAL );
-                break;
-            case ADVANCED:
-                minecraft.getTextureManager().bindTexture( BACKGROUND_ADVANCED );
-                break;
-            case COMMAND:
-                minecraft.getTextureManager().bindTexture( BACKGROUND_COMMAND );
-                break;
-        }
-
-        blit( startX - 12, startY - 12, 12, 28, 12, 12 );
-        blit( startX - 12, endY, 12, 40, 12, 12 );
-        blit( endX, startY - 12, 24, 28, 12, 12 );
-        blit( endX, endY, 24, 40, 12, 12 );
-
-        blit( startX, startY - 12, 0, 0, endX - startX, 12 );
-        blit( startX, endY, 0, 12, endX - startX, 12 );
-
-        blit( startX - 12, startY, 0, 28, 12, endY - startY );
-        blit( endX, startY, 36, 28, 12, endY - startY );
+        RenderSystem.color4f( 1, 1, 1, 1 );
+        minecraft.getTextureManager().bindTexture( ComputerBorderRenderer.getTexture( family ) );
+        ComputerBorderRenderer.render(
+            terminalWrapper.getX() - MARGIN, terminalWrapper.getY() - MARGIN, getBlitOffset(),
+            terminalWrapper.getWidth() + MARGIN * 2, terminalWrapper.getHeight() + MARGIN * 2
+        );
     }
 
     @Override

src/main/java/dan200/computercraft/client/gui/GuiTurtle.java

@@ -49,13 +49,13 @@ public class GuiTurtle extends ContainerScreen<ContainerTurtle>
         super.init();
         minecraft.keyboardListener.enableRepeatEvents( true );
 
-        int termPxWidth = ComputerCraft.terminalWidth_turtle * FixedWidthFontRenderer.FONT_WIDTH;
-        int termPxHeight = ComputerCraft.terminalHeight_turtle * FixedWidthFontRenderer.FONT_HEIGHT;
+        int termPxWidth = ComputerCraft.turtleTermWidth * FixedWidthFontRenderer.FONT_WIDTH;
+        int termPxHeight = ComputerCraft.turtleTermHeight * FixedWidthFontRenderer.FONT_HEIGHT;
 
         terminal = new WidgetTerminal(
             minecraft, () -> m_computer,
-            ComputerCraft.terminalWidth_turtle,
-            ComputerCraft.terminalHeight_turtle,
+            ComputerCraft.turtleTermWidth,
+            ComputerCraft.turtleTermHeight,
             2, 2, 2, 2
         );
         terminalWrapper = new WidgetWrapper( terminal, 2 + 8 + guiLeft, 2 + 8 + guiTop, termPxWidth, termPxHeight );

src/main/java/dan200/computercraft/client/proxy/ComputerCraftProxyClient.java

@@ -10,17 +10,11 @@ import dan200.computercraft.client.gui.*;
 import dan200.computercraft.client.render.TileEntityMonitorRenderer;
 import dan200.computercraft.client.render.TileEntityTurtleRenderer;
 import dan200.computercraft.client.render.TurtlePlayerRenderer;
-import dan200.computercraft.shared.common.ContainerHeldItem;
+import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.computer.inventory.ContainerComputer;
 import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
-import dan200.computercraft.shared.peripheral.diskdrive.ContainerDiskDrive;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
-import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
-import dan200.computercraft.shared.peripheral.printer.ContainerPrinter;
 import dan200.computercraft.shared.pocket.inventory.ContainerPocketComputer;
-import dan200.computercraft.shared.turtle.blocks.TileTurtle;
-import dan200.computercraft.shared.turtle.core.TurtlePlayer;
-import dan200.computercraft.shared.turtle.inventory.ContainerTurtle;
 import net.minecraft.client.gui.ScreenManager;
 import net.minecraft.client.renderer.RenderType;
 import net.minecraft.client.renderer.RenderTypeLookup;
@@ -41,36 +35,36 @@ public final class ComputerCraftProxyClient
         registerContainers();
 
         // While turtles themselves are not transparent, their upgrades may be.
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleNormal, RenderType.getTranslucent() );
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.turtleAdvanced, RenderType.getTranslucent() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_NORMAL.get(), RenderType.getTranslucent() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_ADVANCED.get(), RenderType.getTranslucent() );
 
         // Monitors' textures have transparent fronts and so count as cutouts.
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.monitorNormal, RenderType.getCutout() );
-        RenderTypeLookup.setRenderLayer( ComputerCraft.Blocks.monitorAdvanced, RenderType.getCutout() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_NORMAL.get(), RenderType.getCutout() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_ADVANCED.get(), RenderType.getCutout() );
 
         // Setup TESRs
-        ClientRegistry.bindTileEntityRenderer( TileMonitor.FACTORY_NORMAL, TileEntityMonitorRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( TileMonitor.FACTORY_ADVANCED, TileEntityMonitorRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( TileTurtle.FACTORY_NORMAL, TileEntityTurtleRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( TileTurtle.FACTORY_ADVANCED, TileEntityTurtleRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_NORMAL.get(), TileEntityMonitorRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_ADVANCED.get(), TileEntityMonitorRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_NORMAL.get(), TileEntityTurtleRenderer::new );
+        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_ADVANCED.get(), TileEntityTurtleRenderer::new );
         // TODO: ClientRegistry.bindTileEntityRenderer( TileCable.FACTORY, x -> new TileEntityCableRenderer() );
 
-        RenderingRegistry.registerEntityRenderingHandler( TurtlePlayer.TYPE, TurtlePlayerRenderer::new );
+        RenderingRegistry.registerEntityRenderingHandler( Registry.ModEntities.TURTLE_PLAYER.get(), TurtlePlayerRenderer::new );
     }
 
     private static void registerContainers()
     {
         // My IDE doesn't think so, but we do actually need these generics.
 
-        ScreenManager.<ContainerComputer, GuiComputer<ContainerComputer>>registerFactory( ContainerComputer.TYPE, GuiComputer::create );
-        ScreenManager.<ContainerPocketComputer, GuiComputer<ContainerPocketComputer>>registerFactory( ContainerPocketComputer.TYPE, GuiComputer::createPocket );
-        ScreenManager.registerFactory( ContainerTurtle.TYPE, GuiTurtle::new );
+        ScreenManager.<ContainerComputer, GuiComputer<ContainerComputer>>registerFactory( Registry.ModContainers.COMPUTER.get(), GuiComputer::create );
+        ScreenManager.<ContainerPocketComputer, GuiComputer<ContainerPocketComputer>>registerFactory( Registry.ModContainers.POCKET_COMPUTER.get(), GuiComputer::createPocket );
+        ScreenManager.registerFactory( Registry.ModContainers.TURTLE.get(), GuiTurtle::new );
 
-        ScreenManager.registerFactory( ContainerPrinter.TYPE, GuiPrinter::new );
-        ScreenManager.registerFactory( ContainerDiskDrive.TYPE, GuiDiskDrive::new );
-        ScreenManager.registerFactory( ContainerHeldItem.PRINTOUT_TYPE, GuiPrintout::new );
+        ScreenManager.registerFactory( Registry.ModContainers.PRINTER.get(), GuiPrinter::new );
+        ScreenManager.registerFactory( Registry.ModContainers.DISK_DRIVE.get(), GuiDiskDrive::new );
+        ScreenManager.registerFactory( Registry.ModContainers.PRINTOUT.get(), GuiPrintout::new );
 
-        ScreenManager.<ContainerViewComputer, GuiComputer<ContainerViewComputer>>registerFactory( ContainerViewComputer.TYPE, GuiComputer::createView );
+        ScreenManager.<ContainerViewComputer, GuiComputer<ContainerViewComputer>>registerFactory( Registry.ModContainers.VIEW_COMPUTER.get(), GuiComputer::createView );
     }
 
     @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )

src/main/java/dan200/computercraft/client/render/CableHighlightRenderer.java

@@ -8,6 +8,7 @@ package dan200.computercraft.client.render;
 import com.mojang.blaze3d.matrix.MatrixStack;
 import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.peripheral.modem.wired.BlockCable;
 import dan200.computercraft.shared.peripheral.modem.wired.CableShapes;
 import dan200.computercraft.shared.util.WorldUtil;
@@ -51,7 +52,7 @@ public final class CableHighlightRenderer
         BlockState state = world.getBlockState( pos );
 
         // We only care about instances with both cable and modem.
-        if( state.getBlock() != ComputerCraft.Blocks.cable || state.get( BlockCable.MODEM ).getFacing() == null || !state.get( BlockCable.CABLE ) )
+        if( state.getBlock() != Registry.ModBlocks.CABLE.get() || state.get( BlockCable.MODEM ).getFacing() == null || !state.get( BlockCable.CABLE ) )
         {
             return;
         }

src/main/java/dan200/computercraft/client/render/ComputerBorderRenderer.java

@@ -0,0 +1,175 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client.render;
+
+import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.vertex.IVertexBuilder;
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.computer.core.ComputerFamily;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.util.ResourceLocation;
+import org.lwjgl.opengl.GL11;
+
+import javax.annotation.Nonnull;
+
+public class ComputerBorderRenderer
+{
+    public static final ResourceLocation BACKGROUND_NORMAL = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_normal.png" );
+    public static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_advanced.png" );
+    public static final ResourceLocation BACKGROUND_COMMAND = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_command.png" );
+    public static final ResourceLocation BACKGROUND_COLOUR = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_colour.png" );
+
+    private static final Matrix4f IDENTITY = new Matrix4f();
+
+    static
+    {
+        IDENTITY.setIdentity();
+    }
+
+    /**
+     * The margin between the terminal and its border.
+     */
+    public static final int MARGIN = 2;
+
+    /**
+     * The width of the terminal border.
+     */
+    public static final int BORDER = 12;
+
+    private static final int CORNER_TOP_Y = 28;
+    private static final int CORNER_BOTTOM_Y = CORNER_TOP_Y + BORDER;
+    private static final int CORNER_LEFT_X = BORDER;
+    private static final int CORNER_RIGHT_X = CORNER_LEFT_X + BORDER;
+    private static final int BORDER_RIGHT_X = 36;
+    private static final int GAP = 4;
+
+    private static final float TEX_SCALE = 1 / 256.0f;
+
+    private final Matrix4f transform;
+    private final IVertexBuilder builder;
+    private final int z;
+    private final float r, g, b;
+
+    public ComputerBorderRenderer( Matrix4f transform, IVertexBuilder builder, int z, float r, float g, float b )
+    {
+        this.transform = transform;
+        this.builder = builder;
+        this.z = z;
+        this.r = r;
+        this.g = g;
+        this.b = b;
+    }
+
+
+    @Nonnull
+    public static ResourceLocation getTexture( @Nonnull ComputerFamily family )
+    {
+        switch( family )
+        {
+            case NORMAL:
+            default:
+                return BACKGROUND_NORMAL;
+            case ADVANCED:
+                return BACKGROUND_ADVANCED;
+            case COMMAND:
+                return BACKGROUND_COMMAND;
+        }
+    }
+
+    public static void render( int x, int y, int z, int width, int height )
+    {
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR_TEX );
+
+        render( IDENTITY, buffer, x, y, z, width, height );
+
+        RenderSystem.enableAlphaTest();
+        tessellator.draw();
+    }
+
+    public static void render( Matrix4f transform, IVertexBuilder buffer, int x, int y, int z, int width, int height )
+    {
+        render( transform, buffer, x, y, z, width, height, 1, 1, 1 );
+    }
+
+    public static void render( Matrix4f transform, IVertexBuilder buffer, int x, int y, int z, int width, int height, float r, float g, float b )
+    {
+        render( transform, buffer, x, y, z, width, height, 0, r, g, b );
+    }
+
+    public static void render( Matrix4f transform, IVertexBuilder buffer, int x, int y, int z, int width, int height, int borderHeight, float r, float g, float b )
+    {
+        new ComputerBorderRenderer( transform, buffer, z, r, g, b ).doRender( x, y, width, height, borderHeight );
+    }
+
+    public void doRender( int x, int y, int width, int height, int bottomHeight )
+    {
+        int endX = x + width;
+        int endY = y + height;
+
+        // Vertical bars
+        renderLine( x - BORDER, y, 0, CORNER_TOP_Y, BORDER, endY - y );
+        renderLine( endX, y, BORDER_RIGHT_X, CORNER_TOP_Y, BORDER, endY - y );
+
+        // Top bar
+        renderLine( x, y - BORDER, 0, 0, endX - x, BORDER );
+        renderCorner( x - BORDER, y - BORDER, CORNER_LEFT_X, CORNER_TOP_Y );
+        renderCorner( endX, y - BORDER, CORNER_RIGHT_X, CORNER_TOP_Y );
+
+        // Bottom bar. We allow for drawing a stretched version, which allows for additional elements (such as the
+        // pocket computer's lights).
+        if( bottomHeight <= 0 )
+        {
+            renderLine( x, endY, 0, BORDER, endX - x, BORDER );
+            renderCorner( x - BORDER, endY, CORNER_LEFT_X, CORNER_BOTTOM_Y );
+            renderCorner( endX, endY, CORNER_RIGHT_X, CORNER_BOTTOM_Y );
+        }
+        else
+        {
+            // Bottom left, middle, right. We do this in three portions: the top inner corners, an extended region for
+            // lights, and then the bottom outer corners.
+            renderTexture( x - BORDER, endY, CORNER_LEFT_X, CORNER_BOTTOM_Y, BORDER, BORDER / 2 );
+            renderTexture( x, endY, 0, BORDER, width, BORDER / 2, BORDER, BORDER / 2 );
+            renderTexture( endX, endY, CORNER_RIGHT_X, CORNER_BOTTOM_Y, BORDER, BORDER / 2 );
+
+            renderTexture( x - BORDER, endY + BORDER / 2, CORNER_LEFT_X, CORNER_BOTTOM_Y + GAP, BORDER, bottomHeight, BORDER, GAP );
+            renderTexture( x, endY + BORDER / 2, 0, BORDER + GAP, width, bottomHeight, BORDER, GAP );
+            renderTexture( endX, endY + BORDER / 2, CORNER_RIGHT_X, CORNER_BOTTOM_Y + GAP, BORDER, bottomHeight, BORDER, GAP );
+
+            renderTexture( x - BORDER, endY + bottomHeight + BORDER / 2, CORNER_LEFT_X, CORNER_BOTTOM_Y + BORDER / 2, BORDER, BORDER / 2 );
+            renderTexture( x, endY + bottomHeight + BORDER / 2, 0, BORDER + BORDER / 2, width, BORDER / 2 );
+            renderTexture( endX, endY + bottomHeight + BORDER / 2, CORNER_RIGHT_X, CORNER_BOTTOM_Y + BORDER / 2, BORDER, BORDER / 2 );
+        }
+    }
+
+    private void renderCorner( int x, int y, int u, int v )
+    {
+        renderTexture( x, y, u, v, BORDER, BORDER, BORDER, BORDER );
+    }
+
+    private void renderLine( int x, int y, int u, int v, int width, int height )
+    {
+        renderTexture( x, y, u, v, width, height, BORDER, BORDER );
+    }
+
+    private void renderTexture( int x, int y, int u, int v, int width, int height )
+    {
+        renderTexture( x, y, u, v, width, height, width, height );
+    }
+
+    private void renderTexture( int x, int y, int u, int v, int width, int height, int textureWidth, int textureHeight )
+    {
+        builder.pos( transform, x, y + height, z ).color( r, g, b, 1.0f ).tex( u * TEX_SCALE, (v + textureHeight) * TEX_SCALE ).endVertex();
+        builder.pos( transform, x + width, y + height, z ).color( r, g, b, 1.0f ).tex( (u + textureWidth) * TEX_SCALE, (v + textureHeight) * TEX_SCALE ).endVertex();
+        builder.pos( transform, x + width, y, z ).color( r, g, b, 1.0f ).tex( (u + textureWidth) * TEX_SCALE, v * TEX_SCALE ).endVertex();
+        builder.pos( transform, x, y, z ).color( r, g, b, 1.0f ).tex( u * TEX_SCALE, v * TEX_SCALE ).endVertex();
+    }
+}

src/main/java/dan200/computercraft/client/render/ItemPocketRenderer.java

@@ -7,7 +7,6 @@ package dan200.computercraft.client.render;
 
 import com.mojang.blaze3d.matrix.MatrixStack;
 import com.mojang.blaze3d.systems.RenderSystem;
-import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
@@ -27,7 +26,8 @@ import org.lwjgl.opengl.GL11;
 
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
-import static dan200.computercraft.client.gui.GuiComputer.*;
+import static dan200.computercraft.client.render.ComputerBorderRenderer.BORDER;
+import static dan200.computercraft.client.render.ComputerBorderRenderer.MARGIN;
 
 /**
  * Emulates map rendering for pocket computers.
@@ -35,8 +35,6 @@ import static dan200.computercraft.client.gui.GuiComputer.*;
 @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
 public final class ItemPocketRenderer extends ItemMapLikeRenderer
 {
-    private static final int MARGIN = 2;
-    private static final int FRAME = 12;
     private static final int LIGHT_HEIGHT = 8;
 
     private static final ItemPocketRenderer INSTANCE = new ItemPocketRenderer();
@@ -67,8 +65,8 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
         int termWidth, termHeight;
         if( terminal == null )
         {
-            termWidth = ComputerCraft.terminalWidth_pocketComputer;
-            termHeight = ComputerCraft.terminalHeight_pocketComputer;
+            termWidth = ComputerCraft.pocketTermWidth;
+            termHeight = ComputerCraft.pocketTermHeight;
         }
         else
         {
@@ -86,7 +84,7 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
         transform.rotate( Vector3f.ZP.rotationDegrees( 180f ) );
         transform.scale( 0.5f, 0.5f, 0.5f );
 
-        float scale = 0.75f / Math.max( width + FRAME * 2, height + FRAME * 2 + LIGHT_HEIGHT );
+        float scale = 0.75f / Math.max( width + BORDER * 2, height + BORDER * 2 + LIGHT_HEIGHT );
         transform.scale( scale, scale, 0 );
         transform.translate( -0.5 * width, -0.5 * height, 0 );
 
@@ -117,10 +115,8 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
 
     private static void renderFrame( Matrix4f transform, ComputerFamily family, int colour, int width, int height )
     {
-        Minecraft.getInstance().getTextureManager().bindTexture( colour != -1
-            ? BACKGROUND_COLOUR
-            : family == ComputerFamily.NORMAL ? BACKGROUND_NORMAL : BACKGROUND_ADVANCED
-        );
+        Minecraft.getInstance().getTextureManager()
+            .bindTexture( colour != -1 ? ComputerBorderRenderer.BACKGROUND_COLOUR : ComputerBorderRenderer.getTexture( family ) );
 
         float r = ((colour >>> 16) & 0xFF) / 255.0f;
         float g = ((colour >>> 8) & 0xFF) / 255.0f;
@@ -130,28 +126,7 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
         BufferBuilder buffer = tessellator.getBuffer();
         buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR_TEX );
 
-        // Top left, middle, right
-        renderTexture( transform, buffer, -FRAME, -FRAME, 12, 28, FRAME, FRAME, r, g, b );
-        renderTexture( transform, buffer, 0, -FRAME, 0, 0, width, FRAME, r, g, b );
-        renderTexture( transform, buffer, width, -FRAME, 24, 28, FRAME, FRAME, r, g, b );
-
-        // Left and bright border
-        renderTexture( transform, buffer, -FRAME, 0, 0, 28, FRAME, height, r, g, b );
-        renderTexture( transform, buffer, width, 0, 36, 28, FRAME, height, r, g, b );
-
-        // Bottom left, middle, right. We do this in three portions: the top inner corners, an extended region for
-        // lights, and then the bottom outer corners.
-        renderTexture( transform, buffer, -FRAME, height, 12, 40, FRAME, FRAME / 2, r, g, b );
-        renderTexture( transform, buffer, 0, height, 0, 12, width, FRAME / 2, r, g, b );
-        renderTexture( transform, buffer, width, height, 24, 40, FRAME, FRAME / 2, r, g, b );
-
-        renderTexture( transform, buffer, -FRAME, height + FRAME / 2, 12, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
-        renderTexture( transform, buffer, 0, height + FRAME / 2, 0, 16, width, LIGHT_HEIGHT, FRAME, 4, r, g, b );
-        renderTexture( transform, buffer, width, height + FRAME / 2, 24, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
-
-        renderTexture( transform, buffer, -FRAME, height + LIGHT_HEIGHT + FRAME / 2, 12, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
-        renderTexture( transform, buffer, 0, height + LIGHT_HEIGHT + FRAME / 2, 0, 12 + FRAME / 2, width, FRAME / 2, r, g, b );
-        renderTexture( transform, buffer, width, height + LIGHT_HEIGHT + FRAME / 2, 24, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
+        ComputerBorderRenderer.render( transform, buffer, 0, 0, 0, width, height, LIGHT_HEIGHT, r, g, b );
 
         tessellator.draw();
     }
@@ -168,26 +143,12 @@ public final class ItemPocketRenderer extends ItemMapLikeRenderer
         Tessellator tessellator = Tessellator.getInstance();
         BufferBuilder buffer = tessellator.getBuffer();
         buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR );
-        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + LIGHT_HEIGHT + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( transform, width, height + LIGHT_HEIGHT + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( transform, width, height + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
-        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + FRAME / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + LIGHT_HEIGHT + BORDER / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width, height + LIGHT_HEIGHT + BORDER / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width, height + BORDER / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( transform, width - LIGHT_HEIGHT * 2, height + BORDER / 2.0f, 0 ).color( r, g, b, 1.0f ).endVertex();
 
         tessellator.draw();
         RenderSystem.enableTexture();
     }
-
-    private static void renderTexture( Matrix4f transform, IVertexBuilder builder, int x, int y, int textureX, int textureY, int width, int height, float r, float g, float b )
-    {
-        renderTexture( transform, builder, x, y, textureX, textureY, width, height, width, height, r, g, b );
-    }
-
-    private static void renderTexture( Matrix4f transform, IVertexBuilder builder, int x, int y, int textureX, int textureY, int width, int height, int textureWidth, int textureHeight, float r, float g, float b )
-    {
-        float scale = 1 / 255.0f;
-        builder.pos( transform, x, y + height, 0 ).color( r, g, b, 1.0f ).tex( textureX * scale, (textureY + textureHeight) * scale ).endVertex();
-        builder.pos( transform, x + width, y + height, 0 ).color( r, g, b, 1.0f ).tex( (textureX + textureWidth) * scale, (textureY + textureHeight) * scale ).endVertex();
-        builder.pos( transform, x + width, y, 0 ).color( r, g, b, 1.0f ).tex( (textureX + textureWidth) * scale, textureY * scale ).endVertex();
-        builder.pos( transform, x, y, 0 ).color( r, g, b, 1.0f ).tex( textureX * scale, textureY * scale ).endVertex();
-    }
 }

src/main/java/dan200/computercraft/client/render/MonitorTextureBufferShader.java

@@ -0,0 +1,164 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client.render;
+
+import com.google.common.base.Strings;
+import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.FixedWidthFontRenderer;
+import dan200.computercraft.shared.util.Palette;
+import net.minecraft.client.renderer.Matrix4f;
+import net.minecraft.client.renderer.texture.TextureUtil;
+import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+
+import java.io.InputStream;
+import java.nio.FloatBuffer;
+
+class MonitorTextureBufferShader
+{
+    static final int TEXTURE_INDEX = GL13.GL_TEXTURE3;
+
+    private static final FloatBuffer MATRIX_BUFFER = BufferUtils.createFloatBuffer( 16 );
+    private static final FloatBuffer PALETTE_BUFFER = BufferUtils.createFloatBuffer( 16 * 3 );
+
+    private static int uniformMv;
+
+    private static int uniformFont;
+    private static int uniformWidth;
+    private static int uniformHeight;
+    private static int uniformTbo;
+    private static int uniformPalette;
+
+    private static boolean initialised;
+    private static boolean ok;
+    private static int program;
+
+    static void setupUniform( Matrix4f transform, int width, int height, Palette palette, boolean greyscale )
+    {
+        MATRIX_BUFFER.rewind();
+        transform.write( MATRIX_BUFFER );
+        MATRIX_BUFFER.rewind();
+        RenderSystem.glUniformMatrix4( uniformMv, false, MATRIX_BUFFER );
+
+        RenderSystem.glUniform1i( uniformWidth, width );
+        RenderSystem.glUniform1i( uniformHeight, height );
+
+        // TODO: Cache this? Maybe??
+        PALETTE_BUFFER.rewind();
+        for( int i = 0; i < 16; i++ )
+        {
+            double[] colour = palette.getColour( i );
+            if( greyscale )
+            {
+                float f = FixedWidthFontRenderer.toGreyscale( colour );
+                PALETTE_BUFFER.put( f ).put( f ).put( f );
+            }
+            else
+            {
+                PALETTE_BUFFER.put( (float) colour[0] ).put( (float) colour[1] ).put( (float) colour[2] );
+            }
+        }
+        PALETTE_BUFFER.flip();
+        RenderSystem.glUniform3( uniformPalette, PALETTE_BUFFER );
+    }
+
+    static boolean use()
+    {
+        if( initialised )
+        {
+            if( ok ) GlStateManager.useProgram( program );
+            return ok;
+        }
+
+        if( ok = load() )
+        {
+            GL20.glUseProgram( program );
+            RenderSystem.glUniform1i( uniformFont, 0 );
+            RenderSystem.glUniform1i( uniformTbo, TEXTURE_INDEX - GL13.GL_TEXTURE0 );
+        }
+
+        return ok;
+    }
+
+    private static boolean load()
+    {
+        initialised = true;
+
+        try
+        {
+            int vertexShader = loadShader( GL20.GL_VERTEX_SHADER, "assets/computercraft/shaders/monitor.vert" );
+            int fragmentShader = loadShader( GL20.GL_FRAGMENT_SHADER, "assets/computercraft/shaders/monitor.frag" );
+
+            program = GlStateManager.createProgram();
+            GlStateManager.attachShader( program, vertexShader );
+            GlStateManager.attachShader( program, fragmentShader );
+            GL20.glBindAttribLocation( program, 0, "v_pos" );
+
+            GlStateManager.linkProgram( program );
+            boolean ok = GlStateManager.getProgram( program, GL20.GL_LINK_STATUS ) != 0;
+            String log = GlStateManager.getProgramInfoLog( program, Short.MAX_VALUE ).trim();
+            if( !Strings.isNullOrEmpty( log ) )
+            {
+                ComputerCraft.log.warn( "Problems when linking monitor shader: {}", log );
+            }
+
+            GL20.glDetachShader( program, vertexShader );
+            GL20.glDetachShader( program, fragmentShader );
+            GlStateManager.deleteShader( vertexShader );
+            GlStateManager.deleteShader( fragmentShader );
+
+            if( !ok ) return false;
+
+            uniformMv = getUniformLocation( program, "u_mv" );
+            uniformFont = getUniformLocation( program, "u_font" );
+            uniformWidth = getUniformLocation( program, "u_width" );
+            uniformHeight = getUniformLocation( program, "u_height" );
+            uniformTbo = getUniformLocation( program, "u_tbo" );
+            uniformPalette = getUniformLocation( program, "u_palette" );
+
+            ComputerCraft.log.info( "Loaded monitor shader." );
+            return true;
+        }
+        catch( Exception e )
+        {
+            ComputerCraft.log.error( "Cannot load monitor shaders", e );
+            return false;
+        }
+    }
+
+    private static int loadShader( int kind, String path )
+    {
+        InputStream stream = TileEntityMonitorRenderer.class.getClassLoader().getResourceAsStream( path );
+        if( stream == null ) throw new IllegalArgumentException( "Cannot find " + path );
+        String contents = TextureUtil.readResourceAsString( stream );
+
+        int shader = GlStateManager.createShader( kind );
+
+        GlStateManager.shaderSource( shader, contents );
+        GlStateManager.compileShader( shader );
+
+        boolean ok = GlStateManager.getShader( shader, GL20.GL_COMPILE_STATUS ) != 0;
+        String log = GlStateManager.getShaderInfoLog( shader, Short.MAX_VALUE ).trim();
+        if( !Strings.isNullOrEmpty( log ) )
+        {
+            ComputerCraft.log.warn( "Problems when loading monitor shader {}: {}", path, log );
+        }
+
+        if( !ok ) throw new IllegalStateException( "Cannot compile shader " + path );
+        return shader;
+    }
+
+    private static int getUniformLocation( int program, String name )
+    {
+        int uniform = GlStateManager.getUniformLocation( program, name );
+        if( uniform == -1 ) throw new IllegalStateException( "Cannot find uniform " + name );
+        return uniform;
+    }
+}

src/main/java/dan200/computercraft/client/render/TileEntityMonitorRenderer.java

@@ -6,22 +6,33 @@
 package dan200.computercraft.client.render;
 
 import com.mojang.blaze3d.matrix.MatrixStack;
+import com.mojang.blaze3d.platform.GlStateManager;
 import com.mojang.blaze3d.vertex.IVertexBuilder;
 import dan200.computercraft.client.FrameInfo;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.MonitorRenderer;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
+import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.DirectionUtil;
 import net.minecraft.client.renderer.*;
 import net.minecraft.client.renderer.tileentity.TileEntityRenderer;
 import net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexBuffer;
 import net.minecraft.util.Direction;
 import net.minecraft.util.math.BlockPos;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+import org.lwjgl.opengl.GL31;
 
 import javax.annotation.Nonnull;
+import java.nio.ByteBuffer;
+
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.*;
 
 public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
 {
@@ -30,6 +41,7 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
      * the monitor frame and contents.
      */
     private static final float MARGIN = (float) (TileMonitor.RENDER_MARGIN * 1.1);
+    private static ByteBuffer tboContents;
 
     private static final Matrix4f IDENTITY = TransformationMatrix.identity().getMatrix();
 
@@ -90,50 +102,23 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
         Terminal terminal = originTerminal.getTerminal();
         if( terminal != null )
         {
-            boolean redraw = originTerminal.pollTerminalChanged();
-            if( originTerminal.buffer == null )
-            {
-                originTerminal.createBuffer( MonitorRenderer.VBO );
-                redraw = true;
-            }
-            VertexBuffer vbo = originTerminal.buffer;
-
             // Draw a terminal
-            double xScale = xSize / (terminal.getWidth() * FixedWidthFontRenderer.FONT_WIDTH);
-            double yScale = ySize / (terminal.getHeight() * FixedWidthFontRenderer.FONT_HEIGHT);
+            int width = terminal.getWidth(), height = terminal.getHeight();
+            int pixelWidth = width * FONT_WIDTH, pixelHeight = height * FONT_HEIGHT;
+            double xScale = xSize / pixelWidth;
+            double yScale = ySize / pixelHeight;
             transform.push();
             transform.scale( (float) xScale, (float) -yScale, 1.0f );
 
-            float xMargin = (float) (MARGIN / xScale);
-            float yMargin = (float) (MARGIN / yScale);
-
             Matrix4f matrix = transform.getLast().getMatrix();
 
-            if( redraw )
-            {
-                Tessellator tessellator = Tessellator.getInstance();
-                BufferBuilder builder = tessellator.getBuffer();
-                builder.begin( FixedWidthFontRenderer.TYPE.getDrawMode(), FixedWidthFontRenderer.TYPE.getVertexFormat() );
-                FixedWidthFontRenderer.drawTerminalWithoutCursor(
-                    IDENTITY, builder, 0, 0,
-                    terminal, !originTerminal.isColour(), yMargin, yMargin, xMargin, xMargin
-                );
-
-                builder.finishDrawing();
-                vbo.upload( builder );
-            }
-
             // Sneaky hack here: we get a buffer now in order to flush existing ones and set up the appropriate
             // render state. I've no clue how well this'll work in future versions of Minecraft, but it does the trick
             // for now.
             IVertexBuilder buffer = renderer.getBuffer( FixedWidthFontRenderer.TYPE );
             FixedWidthFontRenderer.TYPE.setupRenderState();
 
-            vbo.bindBuffer();
-            FixedWidthFontRenderer.TYPE.getVertexFormat().setupBufferState( 0L );
-            vbo.draw( matrix, FixedWidthFontRenderer.TYPE.getDrawMode() );
-            VertexBuffer.unbindBuffer();
-            FixedWidthFontRenderer.TYPE.getVertexFormat().clearBufferState();
+            renderTerminal( matrix, originTerminal, (float) (MARGIN / xScale), (float) (MARGIN / yScale) );
 
             // We don't draw the cursor with the VBO, as it's dynamic and so we'll end up refreshing far more than is
             // reasonable.
@@ -158,4 +143,95 @@ public class TileEntityMonitorRenderer extends TileEntityRenderer<TileMonitor>
 
         transform.pop();
     }
+
+    private static void renderTerminal( Matrix4f matrix, ClientMonitor monitor, float xMargin, float yMargin )
+    {
+        Terminal terminal = monitor.getTerminal();
+
+        MonitorRenderer renderType = MonitorRenderer.current();
+        boolean redraw = monitor.pollTerminalChanged();
+        if( monitor.createBuffer( renderType ) ) redraw = true;
+
+        switch( renderType )
+        {
+            case TBO:
+            {
+                if( !MonitorTextureBufferShader.use() ) return;
+
+                int width = terminal.getWidth(), height = terminal.getHeight();
+                int pixelWidth = width * FONT_WIDTH, pixelHeight = height * FONT_HEIGHT;
+
+                if( redraw )
+                {
+                    int size = width * height * 3;
+                    if( tboContents == null || tboContents.capacity() < size )
+                    {
+                        tboContents = GLAllocation.createDirectByteBuffer( size );
+                    }
+
+                    ByteBuffer monitorBuffer = tboContents;
+                    monitorBuffer.clear();
+                    for( int y = 0; y < height; y++ )
+                    {
+                        TextBuffer text = terminal.getLine( y ), textColour = terminal.getTextColourLine( y ), background = terminal.getBackgroundColourLine( y );
+                        for( int x = 0; x < width; x++ )
+                        {
+                            monitorBuffer.put( (byte) (text.charAt( x ) & 0xFF) );
+                            monitorBuffer.put( (byte) getColour( textColour.charAt( x ), Colour.WHITE ) );
+                            monitorBuffer.put( (byte) getColour( background.charAt( x ), Colour.BLACK ) );
+                        }
+                    }
+                    monitorBuffer.flip();
+
+                    GlStateManager.bindBuffer( GL31.GL_TEXTURE_BUFFER, monitor.tboBuffer );
+                    GlStateManager.bufferData( GL31.GL_TEXTURE_BUFFER, monitorBuffer, GL20.GL_STATIC_DRAW );
+                    GlStateManager.bindBuffer( GL31.GL_TEXTURE_BUFFER, 0 );
+                }
+
+                // Nobody knows what they're doing!
+                GlStateManager.activeTexture( MonitorTextureBufferShader.TEXTURE_INDEX );
+                GL11.glBindTexture( GL31.GL_TEXTURE_BUFFER, monitor.tboTexture );
+                GlStateManager.activeTexture( GL13.GL_TEXTURE0 );
+
+                MonitorTextureBufferShader.setupUniform( matrix, width, height, terminal.getPalette(), !monitor.isColour() );
+
+                Tessellator tessellator = Tessellator.getInstance();
+                BufferBuilder buffer = tessellator.getBuffer();
+                buffer.begin( GL11.GL_TRIANGLE_STRIP, DefaultVertexFormats.POSITION );
+                buffer.pos( -xMargin, -yMargin, 0 ).endVertex();
+                buffer.pos( -xMargin, pixelHeight + yMargin, 0 ).endVertex();
+                buffer.pos( pixelWidth + xMargin, -yMargin, 0 ).endVertex();
+                buffer.pos( pixelWidth + xMargin, pixelHeight + yMargin, 0 ).endVertex();
+                tessellator.draw();
+
+                GlStateManager.useProgram( 0 );
+                break;
+            }
+
+            case VBO:
+            {
+                VertexBuffer vbo = monitor.buffer;
+                if( redraw )
+                {
+                    Tessellator tessellator = Tessellator.getInstance();
+                    BufferBuilder builder = tessellator.getBuffer();
+                    builder.begin( FixedWidthFontRenderer.TYPE.getDrawMode(), FixedWidthFontRenderer.TYPE.getVertexFormat() );
+                    FixedWidthFontRenderer.drawTerminalWithoutCursor(
+                        IDENTITY, builder, 0, 0,
+                        terminal, !monitor.isColour(), yMargin, yMargin, xMargin, xMargin
+                    );
+
+                    builder.finishDrawing();
+                    vbo.upload( builder );
+                }
+
+                vbo.bindBuffer();
+                FixedWidthFontRenderer.TYPE.getVertexFormat().setupBufferState( 0L );
+                vbo.draw( matrix, FixedWidthFontRenderer.TYPE.getDrawMode() );
+                VertexBuffer.unbindBuffer();
+                FixedWidthFontRenderer.TYPE.getVertexFormat().clearBufferState();
+                break;
+            }
+        }
+    }
 }

src/main/java/dan200/computercraft/client/render/TurtlePlayerRenderer.java

@@ -7,7 +7,6 @@
 package dan200.computercraft.client.render;
 
 import com.mojang.blaze3d.matrix.MatrixStack;
-import dan200.computercraft.client.gui.GuiComputer;
 import dan200.computercraft.shared.turtle.core.TurtlePlayer;
 import net.minecraft.client.renderer.IRenderTypeBuffer;
 import net.minecraft.client.renderer.entity.EntityRenderer;
@@ -27,7 +26,7 @@ public class TurtlePlayerRenderer extends EntityRenderer<TurtlePlayer>
     @Override
     public ResourceLocation getEntityTexture( @Nonnull TurtlePlayer entity )
     {
-        return GuiComputer.BACKGROUND_NORMAL;
+        return ComputerBorderRenderer.BACKGROUND_NORMAL;
     }
 
     @Override

src/main/java/dan200/computercraft/core/apis/ComputerAccess.java

@@ -116,7 +116,7 @@ public abstract class ComputerAccess implements IComputerAccess
     }
 
     @Override
-    public void queueEvent( @Nonnull final String event, final Object[] arguments )
+    public void queueEvent( @Nonnull String event, Object... arguments )
     {
         Objects.requireNonNull( event, "event cannot be null" );
         m_environment.queueEvent( event, arguments );

src/main/java/dan200/computercraft/core/apis/FSAPI.java

@@ -6,8 +6,8 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.apis.handles.BinaryReadableHandle;
 import dan200.computercraft.core.apis.handles.BinaryWritableHandle;
 import dan200.computercraft.core.apis.handles.EncodedReadableHandle;
@@ -17,7 +17,6 @@ import dan200.computercraft.core.filesystem.FileSystemException;
 import dan200.computercraft.core.filesystem.FileSystemWrapper;
 import dan200.computercraft.core.tracking.TrackingField;
 
-import javax.annotation.Nonnull;
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.nio.channels.ReadableByteChannel;
@@ -29,17 +28,19 @@ import java.util.Map;
 import java.util.OptionalLong;
 import java.util.function.Function;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.getString;
-
+/**
+ * The FS API allows you to manipulate files and the filesystem.
+ *
+ * @cc.module fs
+ */
 public class FSAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_env;
-    private FileSystem m_fileSystem;
+    private final IAPIEnvironment environment;
+    private FileSystem fileSystem = null;
 
     public FSAPI( IAPIEnvironment env )
     {
-        m_env = env;
-        m_fileSystem = null;
+        environment = env;
     }
 
     @Override
@@ -51,329 +52,442 @@ public class FSAPI implements ILuaAPI
     @Override
     public void startup()
     {
-        m_fileSystem = m_env.getFileSystem();
+        fileSystem = environment.getFileSystem();
     }
 
     @Override
     public void shutdown()
     {
-        m_fileSystem = null;
+        fileSystem = null;
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    /**
+     * Returns a list of files in a directory.
+     *
+     * @param path The path to list.
+     * @return A table with a list of files in the directory.
+     * @throws LuaException If the path doesn't exist.
+     */
+    @LuaFunction
+    public final String[] list( String path ) throws LuaException
     {
-        return new String[] {
-            "list",
-            "combine",
-            "getName",
-            "getSize",
-            "exists",
-            "isDir",
-            "isReadOnly",
-            "makeDir",
-            "move",
-            "copy",
-            "delete",
-            "open",
-            "getDrive",
-            "getFreeSpace",
-            "find",
-            "getDir",
-            "getCapacity",
-            "attributes",
-        };
-    }
-
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
-    {
-        switch( method )
+        environment.addTrackingChange( TrackingField.FS_OPS );
+        try
         {
-            case 0:
+            return fileSystem.list( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Combines two parts of a path into one full path, adding separators as
+     * needed.
+     *
+     * @param pathA The first part of the path. For example, a parent directory path.
+     * @param pathB The second part of the path. For example, a file name.
+     * @return The new path, with separators added between parts as needed.
+     */
+    @LuaFunction
+    public final String combine( String pathA, String pathB )
+    {
+        return fileSystem.combine( pathA, pathB );
+    }
+
+    /**
+     * Returns the file name portion of a path.
+     *
+     * @param path The path to get the name from.
+     * @return The final part of the path (the file name).
+     */
+    @LuaFunction
+    public final String getName( String path )
+    {
+        return FileSystem.getName( path );
+    }
+
+    /**
+     * Returns the parent directory portion of a path.
+     *
+     * @param path The path to get the directory from.
+     * @return The path with the final part removed (the parent directory).
+     */
+    @LuaFunction
+    public final String getDir( String path )
+    {
+        return FileSystem.getDirectory( path );
+    }
+
+    /**
+     * Returns the size of the specified file.
+     *
+     * @param path The file to get the file size of.
+     * @return The size of the file, in bytes.
+     * @throws LuaException If the path doesn't exist.
+     */
+    @LuaFunction
+    public final long getSize( String path ) throws LuaException
+    {
+        try
+        {
+            return fileSystem.getSize( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Returns whether the specified path exists.
+     *
+     * @param path The path to check the existence of.
+     * @return Whether the path exists.
+     */
+    @LuaFunction
+    public final boolean exists( String path )
+    {
+        try
+        {
+            return fileSystem.exists( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    /**
+     * Returns whether the specified path is a directory.
+     *
+     * @param path The path to check.
+     * @return Whether the path is a directory.
+     */
+    @LuaFunction
+    public final boolean isDir( String path )
+    {
+        try
+        {
+            return fileSystem.isDir( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    /**
+     * Returns whether a path is read-only.
+     *
+     * @param path The path to check.
+     * @return Whether the path cannot be written to.
+     */
+    @LuaFunction
+    public final boolean isReadOnly( String path )
+    {
+        try
+        {
+            return fileSystem.isReadOnly( path );
+        }
+        catch( FileSystemException e )
+        {
+            return false;
+        }
+    }
+
+    /**
+     * Creates a directory, and any missing parents, at the specified path.
+     *
+     * @param path The path to the directory to create.
+     * @throws LuaException If the directory couldn't be created.
+     */
+    @LuaFunction
+    public final void makeDir( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.makeDir( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Moves a file or directory from one path to another.
+     *
+     * Any parent directories are created as needed.
+     *
+     * @param path The current file or directory to move from.
+     * @param dest The destination path for the file or directory.
+     * @throws LuaException If the file or directory couldn't be moved.
+     */
+    @LuaFunction
+    public final void move( String path, String dest ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.move( path, dest );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Copies a file or directory to a new path.
+     *
+     * Any parent directories are created as needed.
+     *
+     * @param path The file or directory to copy.
+     * @param dest The path to the destination file or directory.
+     * @throws LuaException If the file or directory couldn't be copied.
+     */
+    @LuaFunction
+    public final void copy( String path, String dest ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.copy( path, dest );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Deletes a file or directory.
+     *
+     * If the path points to a directory, all of the enclosed files and
+     * subdirectories are also deleted.
+     *
+     * @param path The path to the file or directory to delete.
+     * @throws LuaException If the file or directory couldn't be deleted.
+     */
+    @LuaFunction
+    public final void delete( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            fileSystem.delete( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    // FIXME: Add individual handle type documentation
+
+    /**
+     * Opens a file for reading or writing at a path.
+     *
+     * The mode parameter can be {@code r} to read, {@code w} to write (deleting
+     * all contents), or {@code a} to append (keeping contents). If {@code b} is
+     * added to the end, the file will be opened in binary mode; otherwise, it's
+     * opened in text mode.
+     *
+     * @param path The path to the file to open.
+     * @param mode The mode to open the file with.
+     * @return A file handle object for the file, or {@code nil} + an error message on error.
+     * @throws LuaException If an invalid mode was specified.
+     * @cc.treturn [1] table A file handle object for the file.
+     * @cc.treturn [2] nil If the file does not exist, or cannot be opened.
+     * @cc.treturn string|nil A message explaining why the file cannot be opened.
+     */
+    @LuaFunction
+    public final Object[] open( String path, String mode ) throws LuaException
+    {
+        environment.addTrackingChange( TrackingField.FS_OPS );
+        try
+        {
+            switch( mode )
             {
-                // list
-                String path = getString( args, 0 );
-                m_env.addTrackingChange( TrackingField.FS_OPS );
-                try
+                case "r":
                 {
-                    return new Object[] { m_fileSystem.list( path ) };
+                    // Open the file for reading, then create a wrapper around the reader
+                    FileSystemWrapper<BufferedReader> reader = fileSystem.openForRead( path, EncodedReadableHandle::openUtf8 );
+                    return new Object[] { new EncodedReadableHandle( reader.get(), reader ) };
                 }
-                catch( FileSystemException e )
+                case "w":
                 {
-                    throw new LuaException( e.getMessage() );
+                    // Open the file for writing, then create a wrapper around the writer
+                    FileSystemWrapper<BufferedWriter> writer = fileSystem.openForWrite( path, false, EncodedWritableHandle::openUtf8 );
+                    return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
                 }
+                case "a":
+                {
+                    // Open the file for appending, then create a wrapper around the writer
+                    FileSystemWrapper<BufferedWriter> writer = fileSystem.openForWrite( path, true, EncodedWritableHandle::openUtf8 );
+                    return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
+                }
+                case "rb":
+                {
+                    // Open the file for binary reading, then create a wrapper around the reader
+                    FileSystemWrapper<ReadableByteChannel> reader = fileSystem.openForRead( path, Function.identity() );
+                    return new Object[] { BinaryReadableHandle.of( reader.get(), reader ) };
+                }
+                case "wb":
+                {
+                    // Open the file for binary writing, then create a wrapper around the writer
+                    FileSystemWrapper<WritableByteChannel> writer = fileSystem.openForWrite( path, false, Function.identity() );
+                    return new Object[] { BinaryWritableHandle.of( writer.get(), writer ) };
+                }
+                case "ab":
+                {
+                    // Open the file for binary appending, then create a wrapper around the reader
+                    FileSystemWrapper<WritableByteChannel> writer = fileSystem.openForWrite( path, true, Function.identity() );
+                    return new Object[] { BinaryWritableHandle.of( writer.get(), writer ) };
+                }
+                default:
+                    throw new LuaException( "Unsupported mode" );
             }
-            case 1:
-            {
-                // combine
-                String pathA = getString( args, 0 );
-                String pathB = getString( args, 1 );
-                return new Object[] { m_fileSystem.combine( pathA, pathB ) };
-            }
-            case 2:
-            {
-                // getName
-                String path = getString( args, 0 );
-                return new Object[] { FileSystem.getName( path ) };
-            }
-            case 3:
-            {
-                // getSize
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.getSize( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 4:
-            {
-                // exists
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.exists( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 5:
-            {
-                // isDir
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.isDir( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 6:
-            {
-                // isReadOnly
-                String path = getString( args, 0 );
-                try
-                {
-                    return new Object[] { m_fileSystem.isReadOnly( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { false };
-                }
-            }
-            case 7:
-            {
-                // makeDir
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.makeDir( path );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 8:
-            {
-                // move
-                String path = getString( args, 0 );
-                String dest = getString( args, 1 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.move( path, dest );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 9:
-            {
-                // copy
-                String path = getString( args, 0 );
-                String dest = getString( args, 1 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.copy( path, dest );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 10:
-            {
-                // delete
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    m_fileSystem.delete( path );
-                    return null;
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 11:
-            {
-                // open
-                String path = getString( args, 0 );
-                String mode = getString( args, 1 );
-                m_env.addTrackingChange( TrackingField.FS_OPS );
-                try
-                {
-                    switch( mode )
-                    {
-                        case "r":
-                        {
-                            // Open the file for reading, then create a wrapper around the reader
-                            FileSystemWrapper<BufferedReader> reader = m_fileSystem.openForRead( path, EncodedReadableHandle::openUtf8 );
-                            return new Object[] { new EncodedReadableHandle( reader.get(), reader ) };
-                        }
-                        case "w":
-                        {
-                            // Open the file for writing, then create a wrapper around the writer
-                            FileSystemWrapper<BufferedWriter> writer = m_fileSystem.openForWrite( path, false, EncodedWritableHandle::openUtf8 );
-                            return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
-                        }
-                        case "a":
-                        {
-                            // Open the file for appending, then create a wrapper around the writer
-                            FileSystemWrapper<BufferedWriter> writer = m_fileSystem.openForWrite( path, true, EncodedWritableHandle::openUtf8 );
-                            return new Object[] { new EncodedWritableHandle( writer.get(), writer ) };
-                        }
-                        case "rb":
-                        {
-                            // Open the file for binary reading, then create a wrapper around the reader
-                            FileSystemWrapper<ReadableByteChannel> reader = m_fileSystem.openForRead( path, Function.identity() );
-                            return new Object[] { new BinaryReadableHandle( reader.get(), reader ) };
-                        }
-                        case "wb":
-                        {
-                            // Open the file for binary writing, then create a wrapper around the writer
-                            FileSystemWrapper<WritableByteChannel> writer = m_fileSystem.openForWrite( path, false, Function.identity() );
-                            return new Object[] { new BinaryWritableHandle( writer.get(), writer ) };
-                        }
-                        case "ab":
-                        {
-                            // Open the file for binary appending, then create a wrapper around the reader
-                            FileSystemWrapper<WritableByteChannel> writer = m_fileSystem.openForWrite( path, true, Function.identity() );
-                            return new Object[] { new BinaryWritableHandle( writer.get(), writer ) };
-                        }
-                        default:
-                            throw new LuaException( "Unsupported mode" );
-                    }
-                }
-                catch( FileSystemException e )
-                {
-                    return new Object[] { null, e.getMessage() };
-                }
-            }
-            case 12:
-            {
-                // getDrive
-                String path = getString( args, 0 );
-                try
-                {
-                    if( !m_fileSystem.exists( path ) )
-                    {
-                        return null;
-                    }
-                    return new Object[] { m_fileSystem.getMountLabel( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 13:
-            {
-                // getFreeSpace
-                String path = getString( args, 0 );
-                try
-                {
-                    long freeSpace = m_fileSystem.getFreeSpace( path );
-                    if( freeSpace >= 0 )
-                    {
-                        return new Object[] { freeSpace };
-                    }
-                    return new Object[] { "unlimited" };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 14: // find
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    m_env.addTrackingChange( TrackingField.FS_OPS );
-                    return new Object[] { m_fileSystem.find( path ) };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 15: // getDir
-            {
-                String path = getString( args, 0 );
-                return new Object[] { FileSystem.getDirectory( path ) };
-            }
-            case 16: // getCapacity
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    OptionalLong capacity = m_fileSystem.getCapacity( path );
-                    return new Object[] { capacity.isPresent() ? capacity.getAsLong() : null };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 17: // attributes
-            {
-                String path = getString( args, 0 );
-                try
-                {
-                    BasicFileAttributes attributes = m_fileSystem.getAttributes( path );
-                    Map<String, Object> result = new HashMap<>();
-                    result.put( "modification", getFileTime( attributes.lastModifiedTime() ) );
-                    result.put( "created", getFileTime( attributes.creationTime() ) );
-                    result.put( "size", attributes.isDirectory() ? 0 : attributes.size() );
-                    result.put( "isDir", attributes.isDirectory() );
-                    return new Object[] { result };
-                }
-                catch( FileSystemException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            default:
-                assert false;
-                return null;
+        }
+        catch( FileSystemException e )
+        {
+            return new Object[] { null, e.getMessage() };
+        }
+    }
+
+    /**
+     * Returns the name of the mount that the specified path is located on.
+     *
+     * @param path The path to get the drive of.
+     * @return The name of the drive that the file is on; e.g. {@code hdd} for local files, or {@code rom} for ROM files.
+     * @throws LuaException If the path doesn't exist.
+     * @cc.treturn string The name of the drive that the file is on; e.g. {@code hdd} for local files, or {@code rom} for ROM files.
+     */
+    @LuaFunction
+    public final Object[] getDrive( String path ) throws LuaException
+    {
+        try
+        {
+            return fileSystem.exists( path ) ? new Object[] { fileSystem.getMountLabel( path ) } : null;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Returns the amount of free space available on the drive the path is
+     * located on.
+     *
+     * @param path The path to check the free space for.
+     * @return The amount of free space available, in bytes.
+     * @cc.treturn number|"unlimited" The amount of free space available, in bytes, or "unlimited".
+     * @throws LuaException If the path doesn't exist.
+     */
+    @LuaFunction
+    public final Object getFreeSpace( String path ) throws LuaException
+    {
+        try
+        {
+            long freeSpace = fileSystem.getFreeSpace( path );
+            return freeSpace >= 0 ? freeSpace : "unlimited";
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Searches for files matching a string with wildcards.
+     *
+     * This string is formatted like a normal path string, but can include any
+     * number of wildcards ({@code *}) to look for files matching anything.
+     * For example, {@code rom/* /command*} will look for any path starting with
+     * {@code command} inside any subdirectory of {@code /rom}.
+     *
+     * @param path The wildcard-qualified path to search for.
+     * @return A list of paths that match the search string.
+     * @throws LuaException If the path doesn't exist.
+     */
+    @LuaFunction
+    public final String[] find( String path ) throws LuaException
+    {
+        try
+        {
+            environment.addTrackingChange( TrackingField.FS_OPS );
+            return fileSystem.find( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Returns true if a path is mounted to the parent filesystem.
+     *
+     * The root filesystem "/" is considered a mount, along with disk folders and the rom folder. Other programs
+     * (such as network shares) can extend this to make other mount types by correctly assigning their return value for
+     * getDrive.
+     *
+     * @param path The path of the drive to get.
+     * @return The drive's capacity.
+     * @throws LuaException If the capacity cannot be determined.
+     * @cc.treturn number|nil This drive's capacity. This will be nil for "read-only" drives, such as the ROM or
+     * treasure disks.
+     */
+    @LuaFunction
+    public final Object getCapacity( String path ) throws LuaException
+    {
+        try
+        {
+            OptionalLong capacity = fileSystem.getCapacity( path );
+            return capacity.isPresent() ? capacity.getAsLong() : null;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Get attributes about a specific file or folder.
+     *
+     * The returned attributes table contains information about the size of the file, whether it is a directory, and
+     * when it was created and last modified.
+     *
+     * The creation and modification times are given as the number of milliseconds since the UNIX epoch. This may be
+     * given to {@link OSAPI#date} in order to convert it to more usable form.
+     *
+     * @param path The path to get attributes for.
+     * @return The resulting attributes.
+     * @throws LuaException If the path does not exist.
+     * @cc.treturn { size = number, isDir = boolean, created = number, modified = number } The resulting attributes.
+     * @see #getSize If you only care about the file's size.
+     * @see #isDir If you only care whether a path is a directory or not.
+     */
+    @LuaFunction
+    public final Map<String, Object> attributes( String path ) throws LuaException
+    {
+        try
+        {
+            BasicFileAttributes attributes = fileSystem.getAttributes( path );
+            Map<String, Object> result = new HashMap<>();
+            result.put( "modification", getFileTime( attributes.lastModifiedTime() ) );
+            result.put( "modified", getFileTime( attributes.lastModifiedTime() ) );
+            result.put( "created", getFileTime( attributes.creationTime() ) );
+            result.put( "size", attributes.isDirectory() ? 0 : attributes.size() );
+            result.put( "isDir", attributes.isDirectory() );
+            return result;
+        }
+        catch( FileSystemException e )
+        {
+            throw new LuaException( e.getMessage() );
         }
     }
 

src/main/java/dan200/computercraft/core/apis/HTTPAPI.java

@@ -6,9 +6,10 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.apis.http.*;
 import dan200.computercraft.core.apis.http.request.HttpRequest;
 import dan200.computercraft.core.apis.http.websocket.Websocket;
@@ -21,10 +22,16 @@ import java.net.URI;
 import java.util.Collections;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
 import static dan200.computercraft.core.apis.TableHelper.*;
 
+/**
+ * The http library allows communicating with web servers, sending and receiving data from them.
+ *
+ * @cc.module http
+ * @hidden
+ */
 public class HTTPAPI implements ILuaAPI
 {
     private final IAPIEnvironment m_apiEnvironment;
@@ -68,135 +75,106 @@ public class HTTPAPI implements ILuaAPI
         Resource.cleanup();
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final Object[] request( IArguments args ) throws LuaException
     {
-        return new String[] {
-            "request",
-            "checkURL",
-            "websocket",
-        };
+        String address, postString, requestMethod;
+        Map<?, ?> headerTable;
+        boolean binary, redirect;
+
+        if( args.get( 0 ) instanceof Map )
+        {
+            Map<?, ?> options = args.getTable( 0 );
+            address = getStringField( options, "url" );
+            postString = optStringField( options, "body", null );
+            headerTable = optTableField( options, "headers", Collections.emptyMap() );
+            binary = optBooleanField( options, "binary", false );
+            requestMethod = optStringField( options, "method", null );
+            redirect = optBooleanField( options, "redirect", true );
+
+        }
+        else
+        {
+            // Get URL and post information
+            address = args.getString( 0 );
+            postString = args.optString( 1, null );
+            headerTable = args.optTable( 2, Collections.emptyMap() );
+            binary = args.optBoolean( 3, false );
+            requestMethod = null;
+            redirect = true;
+        }
+
+        HttpHeaders headers = getHeaders( headerTable );
+
+        HttpMethod httpMethod;
+        if( requestMethod == null )
+        {
+            httpMethod = postString == null ? HttpMethod.GET : HttpMethod.POST;
+        }
+        else
+        {
+            httpMethod = HttpMethod.valueOf( requestMethod.toUpperCase( Locale.ROOT ) );
+            if( httpMethod == null || requestMethod.equalsIgnoreCase( "CONNECT" ) )
+            {
+                throw new LuaException( "Unsupported HTTP method" );
+            }
+        }
+
+        try
+        {
+            URI uri = HttpRequest.checkUri( address );
+            HttpRequest request = new HttpRequest( requests, m_apiEnvironment, address, postString, headers, binary, redirect );
+
+            // Make the request
+            request.queue( r -> r.request( uri, httpMethod ) );
+
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
+        }
     }
 
-    @Override
-    @SuppressWarnings( "resource" )
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    @LuaFunction
+    public final Object[] checkURL( String address )
     {
-        switch( method )
+        try
         {
-            case 0: // request
+            URI uri = HttpRequest.checkUri( address );
+            new CheckUrl( checkUrls, m_apiEnvironment, address, uri ).queue( CheckUrl::run );
+
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
+        }
+    }
+
+    @LuaFunction
+    public final Object[] websocket( String address, Optional<Map<?, ?>> headerTbl ) throws LuaException
+    {
+        if( !ComputerCraft.httpWebsocketEnabled )
+        {
+            throw new LuaException( "Websocket connections are disabled" );
+        }
+
+        HttpHeaders headers = getHeaders( headerTbl.orElse( Collections.emptyMap() ) );
+
+        try
+        {
+            URI uri = Websocket.checkUri( address );
+            if( !new Websocket( websockets, m_apiEnvironment, uri, address, headers ).queue( Websocket::connect ) )
             {
-                String address, postString, requestMethod;
-                Map<?, ?> headerTable;
-                boolean binary, redirect;
-
-                if( args.length >= 1 && args[0] instanceof Map )
-                {
-                    Map<?, ?> options = (Map<?, ?>) args[0];
-                    address = getStringField( options, "url" );
-                    postString = optStringField( options, "body", null );
-                    headerTable = optTableField( options, "headers", Collections.emptyMap() );
-                    binary = optBooleanField( options, "binary", false );
-                    requestMethod = optStringField( options, "method", null );
-                    redirect = optBooleanField( options, "redirect", true );
-
-                }
-                else
-                {
-                    // Get URL and post information
-                    address = getString( args, 0 );
-                    postString = optString( args, 1, null );
-                    headerTable = optTable( args, 2, Collections.emptyMap() );
-                    binary = optBoolean( args, 3, false );
-                    requestMethod = null;
-                    redirect = true;
-                }
-
-                HttpHeaders headers = getHeaders( headerTable );
-
-
-                HttpMethod httpMethod;
-                if( requestMethod == null )
-                {
-                    httpMethod = postString == null ? HttpMethod.GET : HttpMethod.POST;
-                }
-                else
-                {
-                    httpMethod = HttpMethod.valueOf( requestMethod.toUpperCase( Locale.ROOT ) );
-                    if( httpMethod == null || requestMethod.equalsIgnoreCase( "CONNECT" ) )
-                    {
-                        throw new LuaException( "Unsupported HTTP method" );
-                    }
-                }
-
-                try
-                {
-                    URI uri = HttpRequest.checkUri( address );
-                    HttpRequest request = new HttpRequest( requests, m_apiEnvironment, address, postString, headers, binary, redirect );
-
-                    long requestBody = request.body().readableBytes() + HttpRequest.getHeaderSize( headers );
-                    if( ComputerCraft.httpMaxUpload != 0 && requestBody > ComputerCraft.httpMaxUpload )
-                    {
-                        throw new HTTPRequestException( "Request body is too large" );
-                    }
-
-                    // Make the request
-                    request.queue( r -> r.request( uri, httpMethod ) );
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
+                throw new LuaException( "Too many websockets already open" );
             }
-            case 1: // checkURL
-            {
-                String address = getString( args, 0 );
 
-                // Check URL
-                try
-                {
-                    URI uri = HttpRequest.checkUri( address );
-                    new CheckUrl( checkUrls, m_apiEnvironment, address, uri ).queue( CheckUrl::run );
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
-            }
-            case 2: // websocket
-            {
-                String address = getString( args, 0 );
-                Map<?, ?> headerTbl = optTable( args, 1, Collections.emptyMap() );
-
-                if( !ComputerCraft.httpWebsocketEnabled )
-                {
-                    throw new LuaException( "Websocket connections are disabled" );
-                }
-
-                HttpHeaders headers = getHeaders( headerTbl );
-
-                try
-                {
-                    URI uri = Websocket.checkUri( address );
-                    if( !new Websocket( websockets, m_apiEnvironment, uri, address, headers ).queue( Websocket::connect ) )
-                    {
-                        throw new LuaException( "Too many websockets already open" );
-                    }
-
-                    return new Object[] { true };
-                }
-                catch( HTTPRequestException e )
-                {
-                    return new Object[] { false, e.getMessage() };
-                }
-            }
-            default:
-                return null;
+            return new Object[] { true };
+        }
+        catch( HTTPRequestException e )
+        {
+            return new Object[] { false, e.getMessage() };
         }
     }
 

src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java

@@ -43,7 +43,7 @@ public interface IAPIEnvironment
 
     void reboot();
 
-    void queueEvent( String event, Object[] args );
+    void queueEvent( String event, Object... args );
 
     void setOutput( ComputerSide side, int output );
 

src/main/java/dan200/computercraft/core/apis/OSAPI.java

@@ -5,9 +5,10 @@
  */
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.shared.util.StringUtil;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
@@ -20,11 +21,16 @@ import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatterBuilder;
 import java.util.*;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
+import static dan200.computercraft.api.lua.LuaValues.checkFinite;
 
+/**
+ * The {@link OSAPI} API allows interacting with the current computer.
+ *
+ * @cc.module os
+ */
 public class OSAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_apiEnvironment;
+    private final IAPIEnvironment apiEnvironment;
 
     private final Int2ObjectMap<Alarm> m_alarms = new Int2ObjectOpenHashMap<>();
     private int m_clock;
@@ -55,11 +61,9 @@ public class OSAPI implements ILuaAPI
 
     public OSAPI( IAPIEnvironment environment )
     {
-        m_apiEnvironment = environment;
+        apiEnvironment = environment;
     }
 
-    // ILuaAPI implementation
-
     @Override
     public String[] getNames()
     {
@@ -69,8 +73,8 @@ public class OSAPI implements ILuaAPI
     @Override
     public void startup()
     {
-        m_time = m_apiEnvironment.getComputerEnvironment().getTimeOfDay();
-        m_day = m_apiEnvironment.getComputerEnvironment().getDay();
+        m_time = apiEnvironment.getComputerEnvironment().getTimeOfDay();
+        m_day = apiEnvironment.getComputerEnvironment().getDay();
         m_clock = 0;
 
         synchronized( m_alarms )
@@ -89,8 +93,8 @@ public class OSAPI implements ILuaAPI
         {
             double previousTime = m_time;
             int previousDay = m_day;
-            double time = m_apiEnvironment.getComputerEnvironment().getTimeOfDay();
-            int day = m_apiEnvironment.getComputerEnvironment().getDay();
+            double time = apiEnvironment.getComputerEnvironment().getTimeOfDay();
+            int day = apiEnvironment.getComputerEnvironment().getDay();
 
             if( time > previousTime || day > previousDay )
             {
@@ -103,7 +107,7 @@ public class OSAPI implements ILuaAPI
                     double t = alarm.m_day * 24.0 + alarm.m_time;
                     if( now >= t )
                     {
-                        queueLuaEvent( "alarm", new Object[] { entry.getIntKey() } );
+                        apiEnvironment.queueEvent( "alarm", entry.getIntKey() );
                         it.remove();
                     }
                 }
@@ -123,31 +127,6 @@ public class OSAPI implements ILuaAPI
         }
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
-    {
-        return new String[] {
-            "queueEvent",
-            "startTimer",
-            "setAlarm",
-            "shutdown",
-            "reboot",
-            "computerID",
-            "getComputerID",
-            "setComputerLabel",
-            "computerLabel",
-            "getComputerLabel",
-            "clock",
-            "time",
-            "day",
-            "cancelTimer",
-            "cancelAlarm",
-            "epoch",
-            "date",
-        };
-    }
-
     private static float getTimeForCalendar( Calendar c )
     {
         float time = c.get( Calendar.HOUR_OF_DAY );
@@ -174,214 +153,310 @@ public class OSAPI implements ILuaAPI
         return c.getTime().getTime();
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    /**
+     * Adds an event to the event queue. This event can later be pulled with
+     * os.pullEvent.
+     *
+     * @param name The name of the event to queue.
+     * @param args The parameters of the event.
+     * @cc.tparam string name The name of the event to queue.
+     * @cc.param ... The parameters of the event.
+     * @cc.see os.pullEvent To pull the event queued
+     */
+    @LuaFunction
+    public final void queueEvent( String name, IArguments args )
     {
-        switch( method )
+        apiEnvironment.queueEvent( name, args.drop( 1 ).getAll() );
+    }
+
+    /**
+     * Starts a timer that will run for the specified number of seconds. Once
+     * the timer fires, a timer event will be added to the queue with the ID
+     * returned from this function as the first parameter.
+     *
+     * @param timer The number of seconds until the timer fires.
+     * @return The ID of the new timer.
+     * @throws LuaException If the time is below zero.
+     */
+    @LuaFunction
+    public final int startTimer( double timer ) throws LuaException
+    {
+        return apiEnvironment.startTimer( Math.round( checkFinite( 0, timer ) / 0.05 ) );
+    }
+
+    /**
+     * Cancels a timer previously started with startTimer. This will stop the
+     * timer from firing.
+     *
+     * @param token The ID of the timer to cancel.
+     * @see #startTimer To start a timer.
+     */
+    @LuaFunction
+    public final void cancelTimer( int token )
+    {
+        apiEnvironment.cancelTimer( token );
+    }
+
+    /**
+     * Sets an alarm that will fire at the specified world time. When it fires,
+     * an alarm event will be added to the event queue.
+     *
+     * @param time The time at which to fire the alarm, in the range [0.0, 24.0).
+     * @return The ID of the alarm that was set.
+     * @throws LuaException If the time is out of range.
+     */
+    @LuaFunction
+    public final int setAlarm( double time ) throws LuaException
+    {
+        checkFinite( 0, time );
+        if( time < 0.0 || time >= 24.0 ) throw new LuaException( "Number out of range" );
+        synchronized( m_alarms )
         {
-            case 0: // queueEvent
-                queueLuaEvent( getString( args, 0 ), trimArray( args, 1 ) );
-                return null;
-            case 1:
-            {
-                // startTimer
-                double timer = getFiniteDouble( args, 0 );
-                int id = m_apiEnvironment.startTimer( Math.round( timer / 0.05 ) );
-                return new Object[] { id };
-            }
-            case 2:
-            {
-                // setAlarm
-                double time = getFiniteDouble( args, 0 );
-                if( time < 0.0 || time >= 24.0 )
-                {
-                    throw new LuaException( "Number out of range" );
-                }
-                synchronized( m_alarms )
-                {
-                    int day = time > m_time ? m_day : m_day + 1;
-                    m_alarms.put( m_nextAlarmToken, new Alarm( time, day ) );
-                    return new Object[] { m_nextAlarmToken++ };
-                }
-            }
-            case 3: // shutdown
-                m_apiEnvironment.shutdown();
-                return null;
-            case 4: // reboot
-                m_apiEnvironment.reboot();
-                return null;
-            case 5:
-            case 6: // computerID/getComputerID
-                return new Object[] { getComputerID() };
-            case 7:
-            {
-                // setComputerLabel
-                String label = optString( args, 0, null );
-                m_apiEnvironment.setLabel( StringUtil.normaliseLabel( label ) );
-                return null;
-            }
-            case 8:
-            case 9:
-            {
-                // computerLabel/getComputerLabel
-                String label = m_apiEnvironment.getLabel();
-                if( label != null )
-                {
-                    return new Object[] { label };
-                }
-                return null;
-            }
-            case 10: // clock
-                return new Object[] { m_clock * 0.05 };
-            case 11:
-            {
-                // time
-                Object value = args.length > 0 ? args[0] : null;
-                if( value instanceof Map ) return new Object[] { LuaDateTime.fromTable( (Map<?, ?>) value ) };
-
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get Hour of day (UTC)
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getTimeForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get Hour of day (local time)
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getTimeForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get ingame hour
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_time };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 12:
-            {
-                // day
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get numbers of days since 1970-01-01 (utc)
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getDayForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get numbers of days since 1970-01-01 (local time)
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getDayForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get game day
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_day };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 13:
-            {
-                // cancelTimer
-                int token = getInt( args, 0 );
-                m_apiEnvironment.cancelTimer( token );
-                return null;
-            }
-            case 14:
-            {
-                // cancelAlarm
-                int token = getInt( args, 0 );
-                synchronized( m_alarms )
-                {
-                    m_alarms.remove( token );
-                }
-                return null;
-            }
-            case 15: // epoch
-            {
-                String param = optString( args, 0, "ingame" );
-                switch( param.toLowerCase( Locale.ROOT ) )
-                {
-                    case "utc":
-                    {
-                        // Get utc epoch
-                        Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
-                        return new Object[] { getEpochForCalendar( c ) };
-                    }
-                    case "local":
-                    {
-                        // Get local epoch
-                        Calendar c = Calendar.getInstance();
-                        return new Object[] { getEpochForCalendar( c ) };
-                    }
-                    case "ingame":
-                        // Get in-game epoch
-                        synchronized( m_alarms )
-                        {
-                            return new Object[] { m_day * 86400000 + (int) (m_time * 3600000.0f) };
-                        }
-                    default:
-                        throw new LuaException( "Unsupported operation" );
-                }
-            }
-            case 16: // date
-            {
-                String format = optString( args, 0, "%c" );
-                long time = optLong( args, 1, Instant.now().getEpochSecond() );
-
-                Instant instant = Instant.ofEpochSecond( time );
-                ZonedDateTime date;
-                ZoneOffset offset;
-                if( format.startsWith( "!" ) )
-                {
-                    offset = ZoneOffset.UTC;
-                    date = ZonedDateTime.ofInstant( instant, offset );
-                    format = format.substring( 1 );
-                }
-                else
-                {
-                    ZoneId id = ZoneId.systemDefault();
-                    offset = id.getRules().getOffset( instant );
-                    date = ZonedDateTime.ofInstant( instant, id );
-                }
-
-                if( format.equals( "*t" ) ) return new Object[] { LuaDateTime.toTable( date, offset, instant ) };
-
-                DateTimeFormatterBuilder formatter = new DateTimeFormatterBuilder();
-                LuaDateTime.format( formatter, format, offset );
-                return new Object[] { formatter.toFormatter( Locale.ROOT ).format( date ) };
-            }
-            default:
-                return null;
+            int day = time > m_time ? m_day : m_day + 1;
+            m_alarms.put( m_nextAlarmToken, new Alarm( time, day ) );
+            return m_nextAlarmToken++;
         }
     }
 
-    // Private methods
-
-    private void queueLuaEvent( String event, Object[] args )
+    /**
+     * Cancels an alarm previously started with setAlarm. This will stop the
+     * alarm from firing.
+     *
+     * @param token The ID of the alarm to cancel.
+     * @see #setAlarm To set an alarm.
+     */
+    @LuaFunction
+    public final void cancelAlarm( int token )
     {
-        m_apiEnvironment.queueEvent( event, args );
+        synchronized( m_alarms )
+        {
+            m_alarms.remove( token );
+        }
     }
 
-    private Object[] trimArray( Object[] array, int skip )
+    /**
+     * Shuts down the computer immediately.
+     */
+    @LuaFunction( "shutdown" )
+    public final void doShutdown()
     {
-        return Arrays.copyOfRange( array, skip, array.length );
+        apiEnvironment.shutdown();
     }
 
-    private int getComputerID()
+    /**
+     * Reboots the computer immediately.
+     */
+    @LuaFunction( "reboot" )
+    public final void doReboot()
     {
-        return m_apiEnvironment.getComputerID();
+        apiEnvironment.reboot();
     }
+
+    /**
+     * Returns the ID of the computer.
+     *
+     * @return The ID of the computer.
+     */
+    @LuaFunction( { "getComputerID", "computerID" } )
+    public final int getComputerID()
+    {
+        return apiEnvironment.getComputerID();
+    }
+
+    /**
+     * Returns the label of the computer, or {@code nil} if none is set.
+     *
+     * @return The label of the computer.
+     * @cc.treturn string The label of the computer.
+     */
+    @LuaFunction( { "getComputerLabel", "computerLabel" } )
+    public final Object[] getComputerLabel()
+    {
+        String label = apiEnvironment.getLabel();
+        return label == null ? null : new Object[] { label };
+    }
+
+    /**
+     * Set the label of this computer.
+     *
+     * @param label The new label. May be {@code nil} in order to clear it.
+     */
+    @LuaFunction
+    public final void setComputerLabel( Optional<String> label )
+    {
+        apiEnvironment.setLabel( StringUtil.normaliseLabel( label.orElse( null ) ) );
+    }
+
+    /**
+     * Returns the number of seconds that the computer has been running.
+     *
+     * @return The computer's uptime.
+     */
+    @LuaFunction
+    public final double clock()
+    {
+        return m_clock * 0.05;
+    }
+
+    /**
+     * Returns the current time depending on the string passed in. This will
+     * always be in the range [0.0, 24.0).
+     *
+     * * If called with {@code ingame}, the current world time will be returned.
+     *   This is the default if nothing is passed.
+     * * If called with {@code utc}, returns the hour of the day in UTC time.
+     * * If called with {@code local}, returns the hour of the day in the
+     *   timezone the server is located in.
+     *
+     * This function can also be called with a table returned from {@link #date},
+     * which will convert the date fields into a UNIX timestamp (number of
+     * seconds since 1 January 1970).
+     *
+     * @param args The locale of the time, or a table filled by {@code os.date("*t")} to decode. Defaults to {@code ingame} locale if not specified.
+     * @return The hour of the selected locale, or a UNIX timestamp from the table, depending on the argument passed in.
+     * @cc.tparam [opt] string|table locale The locale of the time, or a table filled by {@code os.date("*t")} to decode. Defaults to {@code ingame} locale if not specified.
+     * @see #date To get a date table that can be converted with this function.
+     * @throws LuaException If an invalid locale is passed.
+     */
+    @LuaFunction
+    public final Object time( IArguments args ) throws LuaException
+    {
+        Object value = args.get( 0 );
+        if( value instanceof Map ) return LuaDateTime.fromTable( (Map<?, ?>) value );
+
+        String param = args.optString( 0, "ingame" );
+        switch( param.toLowerCase( Locale.ROOT ) )
+        {
+            case "utc": // Get Hour of day (UTC)
+                return getTimeForCalendar( Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) ) );
+            case "local": // Get Hour of day (local time)
+                return getTimeForCalendar( Calendar.getInstance() );
+            case "ingame": // Get in-game hour
+                return m_time;
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    /**
+     * Returns the day depending on the locale specified.
+     *
+     * * If called with {@code ingame}, returns the number of days since the
+     *   world was created. This is the default.
+     * * If called with {@code utc}, returns the number of days since 1 January
+     *   1970 in the UTC timezone.
+     * * If called with {@code local}, returns the number of days since 1
+     *   January 1970 in the server's local timezone.
+     *
+     * @param args The locale to get the day for. Defaults to {@code ingame} if not set.
+     * @return The day depending on the selected locale.
+     * @throws LuaException If an invalid locale is passed.
+     */
+    @LuaFunction
+    public final int day( Optional<String> args ) throws LuaException
+    {
+        switch( args.orElse( "ingame" ).toLowerCase( Locale.ROOT ) )
+        {
+            case "utc":     // Get numbers of days since 1970-01-01 (utc)
+                return getDayForCalendar( Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) ) );
+            case "local": // Get numbers of days since 1970-01-01 (local time)
+                return getDayForCalendar( Calendar.getInstance() );
+            case "ingame":// Get game day
+                return m_day;
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    /**
+     * Returns the number of seconds since an epoch depending on the locale.
+     *
+     * * If called with {@code ingame}, returns the number of seconds since the
+     *   world was created. This is the default.
+     * * If called with {@code utc}, returns the number of seconds since 1
+     *   January 1970 in the UTC timezone.
+     * * If called with {@code local}, returns the number of seconds since 1
+     *   January 1970 in the server's local timezone.
+     *
+     * @param args The locale to get the seconds for. Defaults to {@code ingame} if not set.
+     * @return The seconds since the epoch depending on the selected locale.
+     * @throws LuaException If an invalid locale is passed.
+     */
+    @LuaFunction
+    public final long epoch( Optional<String> args ) throws LuaException
+    {
+        switch( args.orElse( "ingame" ).toLowerCase( Locale.ROOT ) )
+        {
+            case "utc":
+            {
+                // Get utc epoch
+                Calendar c = Calendar.getInstance( TimeZone.getTimeZone( "UTC" ) );
+                return getEpochForCalendar( c );
+            }
+            case "local":
+            {
+                // Get local epoch
+                Calendar c = Calendar.getInstance();
+                return getEpochForCalendar( c );
+            }
+            case "ingame":
+                // Get in-game epoch
+                synchronized( m_alarms )
+                {
+                    return m_day * 86400000 + (int) (m_time * 3600000.0f);
+                }
+            default:
+                throw new LuaException( "Unsupported operation" );
+        }
+    }
+
+    /**
+     * Returns a date string (or table) using a specified format string and
+     * optional time to format.
+     *
+     * The format string takes the same formats as C's {@code strftime} function
+     * (http://www.cplusplus.com/reference/ctime/strftime/). In extension, it
+     * can be prefixed with an exclamation mark ({@code !}) to use UTC time
+     * instead of the server's local timezone.
+     *
+     * If the format is exactly {@code *t} (optionally prefixed with {@code !}), a
+     * table will be returned instead. This table has fields for the year, month,
+     * day, hour, minute, second, day of the week, day of the year, and whether
+     * Daylight Savings Time is in effect. This table can be converted to a UNIX
+     * timestamp (days since 1 January 1970) with {@link #date}.
+     *
+     * @param formatA The format of the string to return. This defaults to {@code %c}, which expands to a string similar to "Sat Dec 24 16:58:00 2011".
+     * @param timeA The time to convert to a string. This defaults to the current time.
+     * @return The resulting format string.
+     * @throws LuaException If an invalid format is passed.
+     */
+    @LuaFunction
+    public final Object date( Optional<String> formatA, Optional<Long> timeA ) throws LuaException
+    {
+        String format = formatA.orElse( "%c" );
+        long time = timeA.orElseGet( () -> Instant.now().getEpochSecond() );
+
+        Instant instant = Instant.ofEpochSecond( time );
+        ZonedDateTime date;
+        ZoneOffset offset;
+        if( format.startsWith( "!" ) )
+        {
+            offset = ZoneOffset.UTC;
+            date = ZonedDateTime.ofInstant( instant, offset );
+            format = format.substring( 1 );
+        }
+        else
+        {
+            ZoneId id = ZoneId.systemDefault();
+            offset = id.getRules().getOffset( instant );
+            date = ZonedDateTime.ofInstant( instant, id );
+        }
+
+        if( format.equals( "*t" ) ) return LuaDateTime.toTable( date, offset, instant );
+
+        DateTimeFormatterBuilder formatter = new DateTimeFormatterBuilder();
+        LuaDateTime.format( formatter, format, offset );
+        return formatter.toFormatter( Locale.ROOT ).format( date );
+    }
+
 }

src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java

@@ -7,88 +7,80 @@ package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
-import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.*;
+import dan200.computercraft.api.peripheral.IDynamicPeripheral;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.peripheral.IWorkMonitor;
 import dan200.computercraft.api.peripheral.NotAttachedException;
+import dan200.computercraft.core.asm.LuaMethod;
+import dan200.computercraft.core.asm.NamedMethod;
+import dan200.computercraft.core.asm.PeripheralMethod;
 import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.tracking.TrackingField;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.getString;
+import java.util.*;
 
+/**
+ * CC's "native" peripheral API. This is wrapped within CraftOS to provide a version which works with modems.
+ *
+ * @cc.module peripheral
+ * @hidden
+ */
 public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChangeListener
 {
     private class PeripheralWrapper extends ComputerAccess
     {
-        private final String m_side;
-        private final IPeripheral m_peripheral;
+        private final String side;
+        private final IPeripheral peripheral;
 
-        private String m_type;
-        private String[] m_methods;
-        private Map<String, Integer> m_methodMap;
-        private boolean m_attached;
+        private final String type;
+        private final Map<String, PeripheralMethod> methodMap;
+        private boolean attached;
 
         PeripheralWrapper( IPeripheral peripheral, String side )
         {
-            super( m_environment );
-            m_side = side;
-            m_peripheral = peripheral;
-            m_attached = false;
+            super( environment );
+            this.side = side;
+            this.peripheral = peripheral;
+            attached = false;
 
-            m_type = peripheral.getType();
-            m_methods = peripheral.getMethodNames();
-            assert m_type != null;
-            assert m_methods != null;
+            type = Objects.requireNonNull( peripheral.getType(), "Peripheral type cannot be null" );
 
-            m_methodMap = new HashMap<>();
-            for( int i = 0; i < m_methods.length; i++ )
-            {
-                if( m_methods[i] != null )
-                {
-                    m_methodMap.put( m_methods[i], i );
-                }
-            }
+            methodMap = PeripheralAPI.getMethods( peripheral );
         }
 
         public IPeripheral getPeripheral()
         {
-            return m_peripheral;
+            return peripheral;
         }
 
         public String getType()
         {
-            return m_type;
+            return type;
         }
 
-        public String[] getMethods()
+        public Collection<String> getMethods()
         {
-            return m_methods;
+            return methodMap.keySet();
         }
 
         public synchronized boolean isAttached()
         {
-            return m_attached;
+            return attached;
         }
 
         public synchronized void attach()
         {
-            m_attached = true;
-            m_peripheral.attach( this );
+            attached = true;
+            peripheral.attach( this );
         }
 
         public void detach()
         {
             // Call detach
-            m_peripheral.detach( this );
+            peripheral.detach( this );
 
             synchronized( this )
             {
@@ -96,63 +88,56 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                 unmountAll();
             }
 
-            m_attached = false;
+            attached = false;
         }
 
-        public Object[] call( ILuaContext context, String methodName, Object[] arguments ) throws LuaException, InterruptedException
+        public MethodResult call( ILuaContext context, String methodName, IArguments arguments ) throws LuaException
         {
-            int method = -1;
+            PeripheralMethod method;
             synchronized( this )
             {
-                if( m_methodMap.containsKey( methodName ) )
-                {
-                    method = m_methodMap.get( methodName );
-                }
-            }
-            if( method >= 0 )
-            {
-                m_environment.addTrackingChange( TrackingField.PERIPHERAL_OPS );
-                return m_peripheral.callMethod( this, context, method, arguments );
-            }
-            else
-            {
-                throw new LuaException( "No such method " + methodName );
+                method = methodMap.get( methodName );
             }
+
+            if( method == null ) throw new LuaException( "No such method " + methodName );
+
+            environment.addTrackingChange( TrackingField.PERIPHERAL_OPS );
+            return method.apply( peripheral, context, this, arguments );
         }
 
         // IComputerAccess implementation
         @Override
         public synchronized String mount( @Nonnull String desiredLoc, @Nonnull IMount mount, @Nonnull String driveName )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             return super.mount( desiredLoc, mount, driveName );
         }
 
         @Override
         public synchronized String mountWritable( @Nonnull String desiredLoc, @Nonnull IWritableMount mount, @Nonnull String driveName )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             return super.mountWritable( desiredLoc, mount, driveName );
         }
 
         @Override
         public synchronized void unmount( String location )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             super.unmount( location );
         }
 
         @Override
         public int getID()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             return super.getID();
         }
 
         @Override
-        public void queueEvent( @Nonnull final String event, final Object[] arguments )
+        public void queueEvent( @Nonnull String event, Object... arguments )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             super.queueEvent( event, arguments );
         }
 
@@ -160,18 +145,18 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public String getAttachmentName()
         {
-            if( !m_attached ) throw new NotAttachedException();
-            return m_side;
+            if( !attached ) throw new NotAttachedException();
+            return side;
         }
 
         @Nonnull
         @Override
         public Map<String, IPeripheral> getAvailablePeripherals()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
 
             Map<String, IPeripheral> peripherals = new HashMap<>();
-            for( PeripheralWrapper wrapper : m_peripherals )
+            for( PeripheralWrapper wrapper : PeripheralAPI.this.peripherals )
             {
                 if( wrapper != null && wrapper.isAttached() )
                 {
@@ -186,9 +171,9 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public IPeripheral getAvailablePeripheral( @Nonnull String name )
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
 
-            for( PeripheralWrapper wrapper : m_peripherals )
+            for( PeripheralWrapper wrapper : peripherals )
             {
                 if( wrapper != null && wrapper.isAttached() && wrapper.getAttachmentName().equals( name ) )
                 {
@@ -202,27 +187,20 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         @Override
         public IWorkMonitor getMainThreadMonitor()
         {
-            if( !m_attached ) throw new NotAttachedException();
+            if( !attached ) throw new NotAttachedException();
             return super.getMainThreadMonitor();
         }
     }
 
-    private final IAPIEnvironment m_environment;
-    private final PeripheralWrapper[] m_peripherals;
-    private boolean m_running;
+    private final IAPIEnvironment environment;
+    private final PeripheralWrapper[] peripherals = new PeripheralWrapper[6];
+    private boolean running;
 
     public PeripheralAPI( IAPIEnvironment environment )
     {
-        m_environment = environment;
-        m_environment.setPeripheralChangeListener( this );
-
-        m_peripherals = new PeripheralWrapper[6];
-        for( int i = 0; i < 6; i++ )
-        {
-            m_peripherals[i] = null;
-        }
-
-        m_running = false;
+        this.environment = environment;
+        this.environment.setPeripheralChangeListener( this );
+        running = false;
     }
 
     // IPeripheralChangeListener
@@ -230,37 +208,35 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void onPeripheralChanged( ComputerSide side, IPeripheral newPeripheral )
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
             int index = side.ordinal();
-            if( m_peripherals[index] != null )
+            if( peripherals[index] != null )
             {
                 // Queue a detachment
-                final PeripheralWrapper wrapper = m_peripherals[index];
+                final PeripheralWrapper wrapper = peripherals[index];
                 if( wrapper.isAttached() ) wrapper.detach();
 
                 // Queue a detachment event
-                m_environment.queueEvent( "peripheral_detach", new Object[] { side.getName() } );
+                environment.queueEvent( "peripheral_detach", side.getName() );
             }
 
             // Assign the new peripheral
-            m_peripherals[index] = newPeripheral == null ? null
+            peripherals[index] = newPeripheral == null ? null
                 : new PeripheralWrapper( newPeripheral, side.getName() );
 
-            if( m_peripherals[index] != null )
+            if( peripherals[index] != null )
             {
                 // Queue an attachment
-                final PeripheralWrapper wrapper = m_peripherals[index];
-                if( m_running && !wrapper.isAttached() ) wrapper.attach();
+                final PeripheralWrapper wrapper = peripherals[index];
+                if( running && !wrapper.isAttached() ) wrapper.attach();
 
                 // Queue an attachment event
-                m_environment.queueEvent( "peripheral", new Object[] { side.getName() } );
+                environment.queueEvent( "peripheral", side.getName() );
             }
         }
     }
 
-    // ILuaAPI implementation
-
     @Override
     public String[] getNames()
     {
@@ -270,12 +246,12 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void startup()
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
-            m_running = true;
+            running = true;
             for( int i = 0; i < 6; i++ )
             {
-                PeripheralWrapper wrapper = m_peripherals[i];
+                PeripheralWrapper wrapper = peripherals[i];
                 if( wrapper != null && !wrapper.isAttached() ) wrapper.attach();
             }
         }
@@ -284,12 +260,12 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public void shutdown()
     {
-        synchronized( m_peripherals )
+        synchronized( peripherals )
         {
-            m_running = false;
+            running = false;
             for( int i = 0; i < 6; i++ )
             {
-                PeripheralWrapper wrapper = m_peripherals[i];
+                PeripheralWrapper wrapper = peripherals[i];
                 if( wrapper != null && wrapper.isAttached() )
                 {
                     wrapper.detach();
@@ -298,98 +274,95 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    @LuaFunction
+    public final boolean isPresent( String sideName )
     {
-        return new String[] {
-            "isPresent",
-            "getType",
-            "getMethods",
-            "call",
-        };
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side != null )
+        {
+            synchronized( peripherals )
+            {
+                PeripheralWrapper p = peripherals[side.ordinal()];
+                if( p != null ) return true;
+            }
+        }
+        return false;
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException, InterruptedException
+    @LuaFunction
+    public final Object[] getType( String sideName )
     {
-        switch( method )
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side == null ) return null;
+
+        synchronized( peripherals )
         {
-            case 0:
-            {
-                // isPresent
-                boolean present = false;
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) present = true;
-                    }
-                }
-                return new Object[] { present };
-            }
-            case 1:
-            {
-                // getType
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) return new Object[] { p.getType() };
-                    }
-                }
-                return null;
-            }
-            case 2:
-            {
-                // getMethods
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                if( side != null )
-                {
-                    synchronized( m_peripherals )
-                    {
-                        PeripheralWrapper p = m_peripherals[side.ordinal()];
-                        if( p != null ) return new Object[] { p.getMethods() };
-                    }
-                }
+            PeripheralWrapper p = peripherals[side.ordinal()];
+            if( p != null ) return new Object[] { p.getType() };
+        }
+        return null;
+    }
 
-                return null;
-            }
-            case 3:
-            {
-                // call
-                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-                String methodName = getString( args, 1 );
-                Object[] methodArgs = Arrays.copyOfRange( args, 2, args.length );
+    @LuaFunction
+    public final Object[] getMethods( String sideName )
+    {
+        ComputerSide side = ComputerSide.valueOfInsensitive( sideName );
+        if( side == null ) return null;
 
-                if( side == null ) throw new LuaException( "No peripheral attached" );
+        synchronized( peripherals )
+        {
+            PeripheralWrapper p = peripherals[side.ordinal()];
+            if( p != null ) return new Object[] { p.getMethods() };
+        }
+        return null;
+    }
 
-                PeripheralWrapper p;
-                synchronized( m_peripherals )
-                {
-                    p = m_peripherals[side.ordinal()];
-                }
-                if( p == null ) throw new LuaException( "No peripheral attached" );
+    @LuaFunction
+    public final MethodResult call( ILuaContext context, IArguments args ) throws LuaException
+    {
+        ComputerSide side = ComputerSide.valueOfInsensitive( args.getString( 0 ) );
+        String methodName = args.getString( 1 );
+        IArguments methodArgs = args.drop( 2 );
 
-                try
-                {
-                    return p.call( context, methodName, methodArgs );
-                }
-                catch( LuaException e )
-                {
-                    // We increase the error level by one in order to shift the error level to where peripheral.call was
-                    // invoked. It would be possible to do it in Lua code, but would add significantly more overhead.
-                    if( e.getLevel() > 0 ) throw new FastLuaException( e.getMessage(), e.getLevel() + 1 );
-                    throw e;
-                }
-            }
-            default:
-                return null;
+        if( side == null ) throw new LuaException( "No peripheral attached" );
+
+        PeripheralWrapper p;
+        synchronized( peripherals )
+        {
+            p = peripherals[side.ordinal()];
+        }
+        if( p == null ) throw new LuaException( "No peripheral attached" );
+
+        try
+        {
+            return p.call( context, methodName, methodArgs ).adjustError( 1 );
+        }
+        catch( LuaException e )
+        {
+            // We increase the error level by one in order to shift the error level to where peripheral.call was
+            // invoked. It would be possible to do it in Lua code, but would add significantly more overhead.
+            if( e.getLevel() > 0 ) throw new FastLuaException( e.getMessage(), e.getLevel() + 1 );
+            throw e;
         }
     }
 
+    public static Map<String, PeripheralMethod> getMethods( IPeripheral peripheral )
+    {
+        String[] dynamicMethods = peripheral instanceof IDynamicPeripheral
+            ? Objects.requireNonNull( ((IDynamicPeripheral) peripheral).getMethodNames(), "Peripheral methods cannot be null" )
+            : LuaMethod.EMPTY_METHODS;
+
+        List<NamedMethod<PeripheralMethod>> methods = PeripheralMethod.GENERATOR.getMethods( peripheral.getClass() );
+
+        Map<String, PeripheralMethod> methodMap = new HashMap<>( methods.size() + dynamicMethods.length );
+        for( int i = 0; i < dynamicMethods.length; i++ )
+        {
+            methodMap.put( dynamicMethods[i], PeripheralMethod.DYNAMIC.get( i ) );
+        }
+        for( NamedMethod<PeripheralMethod> method : methods )
+        {
+            methodMap.put( method.getName(), method.getMethod() );
+        }
+        return methodMap;
+    }
 }

src/main/java/dan200/computercraft/core/apis/RedstoneAPI.java

@@ -6,21 +6,59 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.computer.ComputerSide;
 
-import javax.annotation.Nonnull;
-
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
-
+/**
+ * Interact with redstone attached to this computer.
+ *
+ * The {@link RedstoneAPI} library exposes three "types" of redstone control:
+ * - Binary input/output ({@link #setOutput}/{@link #getInput}): These simply check if a redstone wire has any input or
+ * output. A signal strength of 1 and 15 are treated the same.
+ * - Analogue input/output ({@link #setAnalogOutput}/{@link #getAnalogInput}): These work with the actual signal
+ * strength of the redstone wired, from 0 to 15.
+ * - Bundled cables ({@link #setBundledOutput}/{@link #getBundledInput}): These interact with "bundled" cables, such
+ * as those from Project:Red. These allow you to send 16 separate on/off signals. Each channel corresponds to a
+ * colour, with the first being @{colors.white} and the last @{colors.black}.
+ *
+ * Whenever a redstone input changes, a {@code redstone} event will be fired. This may be used instead of repeativly
+ * polling.
+ *
+ * This module may also be referred to as {@code rs}. For example, one may call {@code rs.getSides()} instead of
+ * {@link #getSides}.
+ *
+ * @cc.usage Toggle the redstone signal above the computer every 0.5 seconds.
+ *
+ * <pre>
+ * while true do
+ *   redstone.setOutput("top", not redstone.getOutput("top"))
+ *   sleep(0.5)
+ * end
+ * </pre>
+ * @cc.usage Mimic a redstone comparator in [subtraction mode][comparator].
+ *
+ * <pre>
+ * while true do
+ *   local rear = rs.getAnalogueInput("back")
+ *   local sides = math.max(rs.getAnalogueInput("left"), rs.getAnalogueInput("right"))
+ *   rs.setAnalogueOutput("front", math.max(rear - sides, 0))
+ *
+ *   os.pullEvent("redstone") -- Wait for a change to inputs.
+ * end
+ * </pre>
+ *
+ * [comparator]: https://minecraft.gamepedia.com/Redstone_Comparator#Subtract_signal_strength "Redstone Comparator on
+ * the Minecraft wiki."
+ * @cc.module redstone
+ */
 public class RedstoneAPI implements ILuaAPI
 {
-    private IAPIEnvironment m_environment;
+    private final IAPIEnvironment environment;
 
     public RedstoneAPI( IAPIEnvironment environment )
     {
-        m_environment = environment;
+        this.environment = environment;
     }
 
     @Override
@@ -29,95 +67,149 @@ public class RedstoneAPI implements ILuaAPI
         return new String[] { "rs", "redstone" };
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    /**
+     * Returns a table containing the six sides of the computer. Namely, "top", "bottom", "left", "right", "front" and
+     * "back".
+     *
+     * @return A table of valid sides.
+     */
+    @LuaFunction
+    public final String[] getSides()
     {
-        return new String[] {
-            "getSides",
-            "setOutput",
-            "getOutput",
-            "getInput",
-            "setBundledOutput",
-            "getBundledOutput",
-            "getBundledInput",
-            "testBundledInput",
-            "setAnalogOutput",
-            "setAnalogueOutput",
-            "getAnalogOutput",
-            "getAnalogueOutput",
-            "getAnalogInput",
-            "getAnalogueInput",
-        };
+        return ComputerSide.NAMES;
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    /**
+     * Turn the redstone signal of a specific side on or off.
+     *
+     * @param side The side to set.
+     * @param on   Whether the redstone signal should be on or off. When on, a signal strength of 15 is emitted.
+     */
+    @LuaFunction
+    public final void setOutput( ComputerSide side, boolean on )
     {
-        switch( method )
-        {
-            case 0: // getSides
-                return new Object[] { ComputerSide.NAMES };
-            case 1:
-            {
-                // setOutput
-                ComputerSide side = parseSide( args );
-                boolean output = getBoolean( args, 1 );
-                m_environment.setOutput( side, output ? 15 : 0 );
-                return null;
-            }
-            case 2: // getOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) > 0 };
-            case 3: // getInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) > 0 };
-            case 4:
-            {
-                // setBundledOutput
-                ComputerSide side = parseSide( args );
-                int output = getInt( args, 1 );
-                m_environment.setBundledOutput( side, output );
-                return null;
-            }
-            case 5: // getBundledOutput
-                return new Object[] { m_environment.getBundledOutput( parseSide( args ) ) };
-            case 6: // getBundledInput
-                return new Object[] { m_environment.getBundledInput( parseSide( args ) ) };
-            case 7:
-            {
-                // testBundledInput
-                ComputerSide side = parseSide( args );
-                int mask = getInt( args, 1 );
-                int input = m_environment.getBundledInput( side );
-                return new Object[] { (input & mask) == mask };
-            }
-            case 8:
-            case 9:
-            {
-                // setAnalogOutput/setAnalogueOutput
-                ComputerSide side = parseSide( args );
-                int output = getInt( args, 1 );
-                if( output < 0 || output > 15 )
-                {
-                    throw new LuaException( "Expected number in range 0-15" );
-                }
-                m_environment.setOutput( side, output );
-                return null;
-            }
-            case 10:
-            case 11: // getAnalogOutput/getAnalogueOutput
-                return new Object[] { m_environment.getOutput( parseSide( args ) ) };
-            case 12:
-            case 13: // getAnalogInput/getAnalogueInput
-                return new Object[] { m_environment.getInput( parseSide( args ) ) };
-            default:
-                return null;
-        }
+        environment.setOutput( side, on ? 15 : 0 );
     }
 
-    private static ComputerSide parseSide( Object[] args ) throws LuaException
+    /**
+     * Get the current redstone output of a specific side.
+     *
+     * @param side The side to get.
+     * @return Whether the redstone output is on or off.
+     * @see #setOutput
+     */
+    @LuaFunction
+    public final boolean getOutput( ComputerSide side )
     {
-        ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
-        if( side == null ) throw new LuaException( "Invalid side." );
-        return side;
+        return environment.getOutput( side ) > 0;
+    }
+
+    /**
+     * Get the current redstone input of a specific side.
+     *
+     * @param side The side to get.
+     * @return Whether the redstone input is on or off.
+     */
+    @LuaFunction
+    public final boolean getInput( ComputerSide side )
+    {
+        return environment.getInput( side ) > 0;
+    }
+
+    /**
+     * Set the redstone signal strength for a specific side.
+     *
+     * @param side  The side to set.
+     * @param value The signal strength between 0 and 15.
+     * @throws LuaException If {@code value} is not betwene 0 and 15.
+     */
+    @LuaFunction( { "setAnalogOutput", "setAnalogueOutput" } )
+    public final void setAnalogOutput( ComputerSide side, int value ) throws LuaException
+    {
+        if( value < 0 || value > 15 ) throw new LuaException( "Expected number in range 0-15" );
+        environment.setOutput( side, value );
+    }
+
+    /**
+     * Get the redstone output signal strength for a specific side.
+     *
+     * @param side The side to get.
+     * @return The output signal strength, between 0 and 15.
+     * @see #setAnalogOutput
+     */
+    @LuaFunction( { "getAnalogOutput", "getAnalogueOutput" } )
+    public final int getAnalogOutput( ComputerSide side )
+    {
+        return environment.getOutput( side );
+    }
+
+    /**
+     * Get the redstone input signal strength for a specific side.
+     *
+     * @param side The side to get.
+     * @return The input signal strength, between 0 and 15.
+     */
+    @LuaFunction( { "getAnalogInput", "getAnalogueInput" } )
+    public final int getAnalogInput( ComputerSide side )
+    {
+        return environment.getInput( side );
+    }
+
+    /**
+     * Set the bundled cable output for a specific side.
+     *
+     * @param side   The side to set.
+     * @param output The colour bitmask to set.
+     * @cc.see colors.subtract For removing a colour from the bitmask.
+     * @cc.see colors.combine For adding a color to the bitmask.
+     */
+    @LuaFunction
+    public final void setBundledOutput( ComputerSide side, int output )
+    {
+        environment.setBundledOutput( side, output );
+    }
+
+    /**
+     * Get the bundled cable output for a specific side.
+     *
+     * @param side The side to get.
+     * @return The bundle cable's output.
+     */
+    @LuaFunction
+    public final int getBundledOutput( ComputerSide side )
+    {
+        return environment.getBundledOutput( side );
+    }
+
+    /**
+     * Get the bundled cable input for a specific side.
+     *
+     * @param side The side to get.
+     * @return The bundle cable's input.
+     * @see #testBundledInput To determine if a specific colour is set.
+     */
+    @LuaFunction
+    public final int getBundledInput( ComputerSide side )
+    {
+        return environment.getBundledOutput( side );
+    }
+
+    /**
+     * Determine if a specific combination of colours are on for the given side.
+     *
+     * @param side The side to test.
+     * @param mask The mask to test.
+     * @return If the colours are on.
+     * @cc.usage Check if @{colors.white} and @{colors.black} are on above the computer.
+     * <pre>
+     * print(redstone.testBundledInput("top", colors.combine(colors.white, colors.black)))
+     * </pre>
+     * @see #getBundledInput
+     */
+    @LuaFunction
+    public final boolean testBundledInput( ComputerSide side, int mask )
+    {
+        int input = environment.getBundledInput( side );
+        return (input & mask) == mask;
     }
 }

src/main/java/dan200/computercraft/core/apis/TableHelper.java

@@ -5,14 +5,14 @@
  */
 package dan200.computercraft.core.apis;
 
-import dan200.computercraft.api.lua.ArgumentHelper;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaValues;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.util.Map;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.getNumericType;
+import static dan200.computercraft.api.lua.LuaValues.getNumericType;
 
 /**
  * Various helpers for tables.
@@ -27,7 +27,7 @@ public final class TableHelper
     @Nonnull
     public static LuaException badKey( @Nonnull String key, @Nonnull String expected, @Nullable Object actual )
     {
-        return badKey( key, expected, ArgumentHelper.getType( actual ) );
+        return badKey( key, expected, LuaValues.getType( actual ) );
     }
 
     @Nonnull

src/main/java/dan200/computercraft/core/apis/TermAPI.java

@@ -5,28 +5,30 @@
  */
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.ILuaAPI;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.core.computer.IComputerEnvironment;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.util.Colour;
-import dan200.computercraft.shared.util.Palette;
-import org.apache.commons.lang3.ArrayUtils;
 
 import javax.annotation.Nonnull;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.*;
-
-public class TermAPI implements ILuaAPI
+/**
+ * The Terminal API provides functions for writing text to the terminal and monitors, and drawing ASCII graphics.
+ *
+ * @cc.module term
+ */
+public class TermAPI extends TermMethods implements ILuaAPI
 {
-    private final Terminal m_terminal;
-    private final IComputerEnvironment m_environment;
+    private final Terminal terminal;
+    private final IComputerEnvironment environment;
 
     public TermAPI( IAPIEnvironment environment )
     {
-        m_terminal = environment.getTerminal();
-        m_environment = environment.getComputerEnvironment();
+        terminal = environment.getTerminal();
+        this.environment = environment.getComputerEnvironment();
     }
 
     @Override
@@ -35,262 +37,40 @@ public class TermAPI implements ILuaAPI
         return new String[] { "term" };
     }
 
+    /**
+     * Get the default palette value for a colour.
+     *
+     * @param colour The colour whose palette should be fetched.
+     * @return The RGB values.
+     * @throws LuaException When given an invalid colour.
+     * @cc.treturn number The red channel, will be between 0 and 1.
+     * @cc.treturn number The green channel, will be between 0 and 1.
+     * @cc.treturn number The blue channel, will be between 0 and 1.
+     * @see TermMethods#setPaletteColour(IArguments) To change the palette colour.
+     */
+    @LuaFunction( { "nativePaletteColour", "nativePaletteColor" } )
+    public final Object[] nativePaletteColour( int colour ) throws LuaException
+    {
+        int actualColour = 15 - parseColour( colour );
+        Colour c = Colour.fromInt( actualColour );
+
+        float[] rgb = c.getRGB();
+
+        Object[] rgbObj = new Object[rgb.length];
+        for( int i = 0; i < rgbObj.length; ++i ) rgbObj[i] = rgb[i];
+        return rgbObj;
+    }
+
     @Nonnull
     @Override
-    public String[] getMethodNames()
+    public Terminal getTerminal()
     {
-        return new String[] {
-            "write",
-            "scroll",
-            "setCursorPos",
-            "setCursorBlink",
-            "getCursorPos",
-            "getSize",
-            "clear",
-            "clearLine",
-            "setTextColour",
-            "setTextColor",
-            "setBackgroundColour",
-            "setBackgroundColor",
-            "isColour",
-            "isColor",
-            "getTextColour",
-            "getTextColor",
-            "getBackgroundColour",
-            "getBackgroundColor",
-            "blit",
-            "setPaletteColour",
-            "setPaletteColor",
-            "getPaletteColour",
-            "getPaletteColor",
-            "nativePaletteColour",
-            "nativePaletteColor",
-            "getCursorBlink",
-        };
-    }
-
-    public static int parseColour( Object[] args ) throws LuaException
-    {
-        int colour = getInt( args, 0 );
-        if( colour <= 0 )
-        {
-            throw new LuaException( "Colour out of range" );
-        }
-        colour = getHighestBit( colour ) - 1;
-        if( colour < 0 || colour > 15 )
-        {
-            throw new LuaException( "Colour out of range" );
-        }
-        return colour;
-    }
-
-    public static Object[] encodeColour( int colour ) throws LuaException
-    {
-        return new Object[] { 1 << colour };
-    }
-
-    public static void setColour( Terminal terminal, int colour, double r, double g, double b )
-    {
-        if( terminal.getPalette() != null )
-        {
-            terminal.getPalette().setColour( colour, r, g, b );
-            terminal.setChanged();
-        }
+        return terminal;
     }
 
     @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    public boolean isColour()
     {
-        switch( method )
-        {
-            case 0:
-            {
-                // write
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                synchronized( m_terminal )
-                {
-                    m_terminal.write( text );
-                    m_terminal.setCursorPos( m_terminal.getCursorX() + text.length(), m_terminal.getCursorY() );
-                }
-                return null;
-            }
-            case 1:
-            {
-                // scroll
-                int y = getInt( args, 0 );
-                synchronized( m_terminal )
-                {
-                    m_terminal.scroll( y );
-                }
-                return null;
-            }
-            case 2:
-            {
-                // setCursorPos
-                int x = getInt( args, 0 ) - 1;
-                int y = getInt( args, 1 ) - 1;
-                synchronized( m_terminal )
-                {
-                    m_terminal.setCursorPos( x, y );
-                }
-                return null;
-            }
-            case 3:
-            {
-                // setCursorBlink
-                boolean b = getBoolean( args, 0 );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setCursorBlink( b );
-                }
-                return null;
-            }
-            case 4:
-            {
-                // getCursorPos
-                int x, y;
-                synchronized( m_terminal )
-                {
-                    x = m_terminal.getCursorX();
-                    y = m_terminal.getCursorY();
-                }
-                return new Object[] { x + 1, y + 1 };
-            }
-            case 5:
-            {
-                // getSize
-                int width, height;
-                synchronized( m_terminal )
-                {
-                    width = m_terminal.getWidth();
-                    height = m_terminal.getHeight();
-                }
-                return new Object[] { width, height };
-            }
-            case 6: // clear
-                synchronized( m_terminal )
-                {
-                    m_terminal.clear();
-                }
-                return null;
-            case 7: // clearLine
-                synchronized( m_terminal )
-                {
-                    m_terminal.clearLine();
-                }
-                return null;
-            case 8:
-            case 9:
-            {
-                // setTextColour/setTextColor
-                int colour = parseColour( args );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setTextColour( colour );
-                }
-                return null;
-            }
-            case 10:
-            case 11:
-            {
-                // setBackgroundColour/setBackgroundColor
-                int colour = parseColour( args );
-                synchronized( m_terminal )
-                {
-                    m_terminal.setBackgroundColour( colour );
-                }
-                return null;
-            }
-            case 12:
-            case 13: // isColour/isColor
-                return new Object[] { m_environment.isColour() };
-            case 14:
-            case 15: // getTextColour/getTextColor
-                return encodeColour( m_terminal.getTextColour() );
-            case 16:
-            case 17: // getBackgroundColour/getBackgroundColor
-                return encodeColour( m_terminal.getBackgroundColour() );
-            case 18:
-            {
-                // blit
-                String text = getString( args, 0 );
-                String textColour = getString( args, 1 );
-                String backgroundColour = getString( args, 2 );
-                if( textColour.length() != text.length() || backgroundColour.length() != text.length() )
-                {
-                    throw new LuaException( "Arguments must be the same length" );
-                }
-
-                synchronized( m_terminal )
-                {
-                    m_terminal.blit( text, textColour, backgroundColour );
-                    m_terminal.setCursorPos( m_terminal.getCursorX() + text.length(), m_terminal.getCursorY() );
-                }
-                return null;
-            }
-            case 19:
-            case 20:
-            {
-                // setPaletteColour/setPaletteColor
-                int colour = 15 - parseColour( args );
-                if( args.length == 2 )
-                {
-                    int hex = getInt( args, 1 );
-                    double[] rgb = Palette.decodeRGB8( hex );
-                    setColour( m_terminal, colour, rgb[0], rgb[1], rgb[2] );
-                }
-                else
-                {
-                    double r = getFiniteDouble( args, 1 );
-                    double g = getFiniteDouble( args, 2 );
-                    double b = getFiniteDouble( args, 3 );
-                    setColour( m_terminal, colour, r, g, b );
-                }
-                return null;
-            }
-            case 21:
-            case 22:
-            {
-                // getPaletteColour/getPaletteColor
-                int colour = 15 - parseColour( args );
-                synchronized( m_terminal )
-                {
-                    if( m_terminal.getPalette() != null )
-                    {
-                        return ArrayUtils.toObject( m_terminal.getPalette().getColour( colour ) );
-                    }
-                }
-                return null;
-            }
-            case 23:
-            case 24:
-            {
-                // nativePaletteColour/nativePaletteColor
-                int colour = 15 - parseColour( args );
-                Colour c = Colour.fromInt( colour );
-
-                float[] rgb = c.getRGB();
-
-                Object[] rgbObj = new Object[rgb.length];
-                for( int i = 0; i < rgbObj.length; ++i ) rgbObj[i] = rgb[i];
-                return rgbObj;
-            }
-            case 25:
-                // getCursorBlink
-                return new Object[] { m_terminal.getCursorBlink() };
-            default:
-                return null;
-        }
-    }
-
-    private static int getHighestBit( int group )
-    {
-        int bit = 0;
-        while( group > 0 )
-        {
-            group >>= 1;
-            bit++;
-        }
-        return bit;
+        return environment.isColour();
     }
 }

src/main/java/dan200/computercraft/core/apis/TermMethods.java

@@ -0,0 +1,383 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis;
+
+import dan200.computercraft.api.lua.IArguments;
+import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.shared.util.Palette;
+import dan200.computercraft.shared.util.StringUtil;
+import org.apache.commons.lang3.ArrayUtils;
+
+import javax.annotation.Nonnull;
+
+/**
+ * A base class for all objects which interact with a terminal. Namely the {@link TermAPI} and monitors.
+ *
+ * @cc.module term.Redirect
+ */
+public abstract class TermMethods
+{
+    private static int getHighestBit( int group )
+    {
+        int bit = 0;
+        while( group > 0 )
+        {
+            group >>= 1;
+            bit++;
+        }
+        return bit;
+    }
+
+    @Nonnull
+    public abstract Terminal getTerminal() throws LuaException;
+
+    public abstract boolean isColour() throws LuaException;
+
+    /**
+     * Write {@code text} at the current cursor position, moving the cursor to the end of the text.
+     *
+     * Unlike functions like {@code write} and {@code print}, this does not wrap the text - it simply copies the
+     * text to the current terminal line.
+     *
+     * @param arguments The text to write.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.param text The text to write.
+     */
+    @LuaFunction
+    public final void write( IArguments arguments ) throws LuaException
+    {
+        String text = StringUtil.toString( arguments.get( 0 ) );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.write( text );
+            terminal.setCursorPos( terminal.getCursorX() + text.length(), terminal.getCursorY() );
+        }
+    }
+
+    /**
+     * Move all positions up (or down) by {@code y} pixels.
+     *
+     * Every pixel in the terminal will be replaced by the line {@code y} pixels below it. If {@code y} is negative, it
+     * will copy pixels from above instead.
+     *
+     * @param y The number of lines to move up by. This may be a negative number.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final void scroll( int y ) throws LuaException
+    {
+        getTerminal().scroll( y );
+    }
+
+    /**
+     * Get the position of the cursor.
+     *
+     * @return The cursor's position.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.treturn number The x position of the cursor.
+     * @cc.treturn number The y position of the cursor.
+     */
+    @LuaFunction
+    public final Object[] getCursorPos() throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        return new Object[] { terminal.getCursorX() + 1, terminal.getCursorY() + 1 };
+    }
+
+    /**
+     * Set the position of the cursor. {@link #write(IArguments) terminal writes} will begin from this position.
+     *
+     * @param x The new x position of the cursor.
+     * @param y The new y position of the cursor.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final void setCursorPos( int x, int y ) throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setCursorPos( x - 1, y - 1 );
+        }
+    }
+
+    /**
+     * Checks if the cursor is currently blinking.
+     *
+     * @return If the cursor is blinking.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final boolean getCursorBlink() throws LuaException
+    {
+        return getTerminal().getCursorBlink();
+    }
+
+    /**
+     * Sets whether the cursor should be visible (and blinking) at the current {@link #getCursorPos() cursor position}.
+     *
+     * @param blink Whether the cursor should blink.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final void setCursorBlink( boolean blink ) throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setCursorBlink( blink );
+        }
+    }
+
+    /**
+     * Get the size of the terminal.
+     *
+     * @return The terminal's size.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.treturn number The terminal's width.
+     * @cc.treturn number The terminal's height.
+     */
+    @LuaFunction
+    public final Object[] getSize() throws LuaException
+    {
+        Terminal terminal = getTerminal();
+        return new Object[] { terminal.getWidth(), terminal.getHeight() };
+    }
+
+    /**
+     * Clears the terminal, filling it with the {@link #getBackgroundColour() current background colour}.
+     *
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final void clear() throws LuaException
+    {
+        getTerminal().clear();
+    }
+
+    /**
+     * Clears the line the cursor is currently on, filling it with the {@link #getBackgroundColour() current background
+     * colour}.
+     *
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction
+    public final void clearLine() throws LuaException
+    {
+        getTerminal().clearLine();
+    }
+
+    /**
+     * Return the colour that new text will be written as.
+     *
+     * @return The current text colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.see colors For a list of colour constants, returned by this function.
+     */
+    @LuaFunction( { "getTextColour", "getTextColor" } )
+    public final int getTextColour() throws LuaException
+    {
+        return encodeColour( getTerminal().getTextColour() );
+    }
+
+    /**
+     * Set the colour that new text will be written as.
+     *
+     * @param colourArg The new text colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.see colors For a list of colour constants.
+     */
+    @LuaFunction( { "setTextColour", "setTextColor" } )
+    public final void setTextColour( int colourArg ) throws LuaException
+    {
+        int colour = parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setTextColour( colour );
+        }
+    }
+
+    /**
+     * Return the current background colour. This is used when {@link #write writing text} and {@link #clear clearing}
+     * the terminal.
+     *
+     * @return The current background colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.see colors For a list of colour constants, returned by this function.
+     */
+    @LuaFunction( { "getBackgroundColour", "getBackgroundColor" } )
+    public final int getBackgroundColour() throws LuaException
+    {
+        return encodeColour( getTerminal().getBackgroundColour() );
+    }
+
+    /**
+     * Set the current background colour. This is used when {@link #write writing text} and {@link #clear clearing} the
+     * terminal.
+     *
+     * @param colourArg The new background colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.see colors For a list of colour constants.
+     */
+    @LuaFunction( { "setBackgroundColour", "setBackgroundColor" } )
+    public final void setBackgroundColour( int colourArg ) throws LuaException
+    {
+        int colour = parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.setBackgroundColour( colour );
+        }
+    }
+
+    /**
+     * Determine if this terminal supports colour.
+     *
+     * Terminals which do not support colour will still allow writing coloured text/backgrounds, but it will be
+     * displayed in greyscale.
+     *
+     * @return Whether this terminal supports colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     */
+    @LuaFunction( { "isColour", "isColor" } )
+    public final boolean getIsColour() throws LuaException
+    {
+        return isColour();
+    }
+
+    /**
+     * Writes {@code text} to the terminal with the specific foreground and background characters.
+     *
+     * As with {@link #write(IArguments)}, the text will be written at the current cursor location, with the cursor
+     * moving to the end of the text.
+     *
+     * {@code textColour} and {@code backgroundColour} must both be strings the same length as {@code text}. All
+     * characters represent a single hexadecimal digit, which is converted to one of CC's colours. For instance,
+     * {@code "a"} corresponds to purple.
+     *
+     * @param text             The text to write.
+     * @param textColour       The corresponding text colours.
+     * @param backgroundColour The corresponding background colours.
+     * @throws LuaException If the three inputs are not the same length.
+     * @cc.see colors For a list of colour constants, and their hexadecimal values.
+     * @cc.usage Prints "Hello, world!" in rainbow text.
+     * <pre>{@code
+     * term.blit("Hello, world!","01234456789ab","0000000000000")
+     * }</pre>
+     */
+    @LuaFunction
+    public final void blit( String text, String textColour, String backgroundColour ) throws LuaException
+    {
+        if( textColour.length() != text.length() || backgroundColour.length() != text.length() )
+        {
+            throw new LuaException( "Arguments must be the same length" );
+        }
+
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            terminal.blit( text, textColour, backgroundColour );
+            terminal.setCursorPos( terminal.getCursorX() + text.length(), terminal.getCursorY() );
+        }
+    }
+
+    /**
+     * Set the palette for a specific colour.
+     *
+     * ComputerCraft's palette system allows you to change how a specific colour should be displayed. For instance, you
+     * can make @{colors.red} <em>more red</em> by setting its palette to #FF0000. This does now allow you to draw more
+     * colours - you are still limited to 16 on the screen at one time - but you can change <em>which</em> colours are
+     * used.
+     *
+     * @param args The new palette values.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.tparam [1] number index The colour whose palette should be changed.
+     * @cc.tparam number colour A 24-bit integer representing the RGB value of the colour. For instance the integer
+     * `0xFF0000` corresponds to the colour #FF0000.
+     * @cc.tparam [2] number index The colour whose palette should be changed.
+     * @cc.tparam number r The intensity of the red channel, between 0 and 1.
+     * @cc.tparam number g The intensity of the green channel, between 0 and 1.
+     * @cc.tparam number b The intensity of the blue channel, between 0 and 1.
+     * @cc.usage Change the @{colors.red|red colour} from the default #CC4C4C to #FF0000.
+     * <pre>{@code
+     * term.setPaletteColour(colors.red, 0xFF0000)
+     * term.setTextColour(colors.red)
+     * print("Hello, world!")
+     * }</pre>
+     * @cc.usage As above, but specifying each colour channel separately.
+     * <pre>{@code
+     * term.setPaletteColour(colors.red, 1, 0, 0)
+     * term.setTextColour(colors.red)
+     * print("Hello, world!")
+     * }</pre>
+     * @cc.see colors.unpackRGB To convert from the 24-bit format to three separate channels.
+     * @cc.see colors.packRGB To convert from three separate channels to the 24-bit format.
+     */
+    @LuaFunction( { "setPaletteColour", "setPaletteColor" } )
+    public final void setPaletteColour( IArguments args ) throws LuaException
+    {
+        int colour = 15 - parseColour( args.getInt( 0 ) );
+        if( args.count() == 2 )
+        {
+            int hex = args.getInt( 1 );
+            double[] rgb = Palette.decodeRGB8( hex );
+            setColour( getTerminal(), colour, rgb[0], rgb[1], rgb[2] );
+        }
+        else
+        {
+            double r = args.getFiniteDouble( 1 );
+            double g = args.getFiniteDouble( 2 );
+            double b = args.getFiniteDouble( 3 );
+            setColour( getTerminal(), colour, r, g, b );
+        }
+    }
+
+    /**
+     * Get the current palette for a specific colour.
+     *
+     * @param colourArg The colour whose palette should be fetched.
+     * @return The resulting colour.
+     * @throws LuaException (hidden) If the terminal cannot be found.
+     * @cc.treturn number The red channel, will be between 0 and 1.
+     * @cc.treturn number The green channel, will be between 0 and 1.
+     * @cc.treturn number The blue channel, will be between 0 and 1.
+     */
+    @LuaFunction( { "getPaletteColour", "getPaletteColor" } )
+    public final Object[] getPaletteColour( int colourArg ) throws LuaException
+    {
+        int colour = 15 - parseColour( colourArg );
+        Terminal terminal = getTerminal();
+        synchronized( terminal )
+        {
+            return ArrayUtils.toObject( terminal.getPalette().getColour( colour ) );
+        }
+    }
+
+    public static int parseColour( int colour ) throws LuaException
+    {
+        if( colour <= 0 ) throw new LuaException( "Colour out of range" );
+        colour = getHighestBit( colour ) - 1;
+        if( colour < 0 || colour > 15 ) throw new LuaException( "Colour out of range" );
+        return colour;
+    }
+
+
+    public static int encodeColour( int colour )
+    {
+        return 1 << colour;
+    }
+
+    public static void setColour( Terminal terminal, int colour, double r, double g, double b )
+    {
+        terminal.getPalette().setColour( colour, r, g, b );
+        terminal.setChanged();
+    }
+}

src/main/java/dan200/computercraft/core/apis/handles/BinaryReadableHandle.java

@@ -5,11 +5,9 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import com.google.common.collect.ObjectArrays;
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 
-import javax.annotation.Nonnull;
 import java.io.ByteArrayOutputStream;
 import java.io.Closeable;
 import java.io.IOException;
@@ -17,208 +15,256 @@ import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.SeekableByteChannel;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.getInt;
-import static dan200.computercraft.api.lua.ArgumentHelper.optBoolean;
-
+/**
+ * A file handle opened with {@link dan200.computercraft.core.apis.FSAPI#open(String, String)} with the {@code "rb"}
+ * mode.
+ *
+ * @cc.module fs.BinaryReadHandle
+ */
 public class BinaryReadableHandle extends HandleGeneric
 {
     private static final int BUFFER_SIZE = 8192;
 
-    private static final String[] METHOD_NAMES = new String[] { "read", "readAll", "readLine", "close" };
-    private static final String[] METHOD_SEEK_NAMES = ObjectArrays.concat( METHOD_NAMES, new String[] { "seek" }, String.class );
-
-    private final ReadableByteChannel m_reader;
-    private final SeekableByteChannel m_seekable;
+    private final ReadableByteChannel reader;
+    final SeekableByteChannel seekable;
     private final ByteBuffer single = ByteBuffer.allocate( 1 );
 
-    public BinaryReadableHandle( ReadableByteChannel channel, Closeable closeable )
+    BinaryReadableHandle( ReadableByteChannel reader, SeekableByteChannel seekable, Closeable closeable )
     {
         super( closeable );
-        m_reader = channel;
-        m_seekable = asSeekable( channel );
+        this.reader = reader;
+        this.seekable = seekable;
     }
 
-    public BinaryReadableHandle( ReadableByteChannel channel )
+    public static BinaryReadableHandle of( ReadableByteChannel channel, Closeable closeable )
     {
-        this( channel, channel );
+        SeekableByteChannel seekable = asSeekable( channel );
+        return seekable == null ? new BinaryReadableHandle( channel, null, closeable ) : new Seekable( seekable, closeable );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    public static BinaryReadableHandle of( ReadableByteChannel channel )
     {
-        return m_seekable == null ? METHOD_NAMES : METHOD_SEEK_NAMES;
+        return of( channel, channel );
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    /**
+     * Read a number of bytes from this file.
+     *
+     * @param countArg The number of bytes to read. When absent, a single byte will be read <em>as a number</em>. This
+     *                 may be 0 to determine we are at the end of the file.
+     * @return The read bytes.
+     * @throws LuaException When trying to read a negative number of bytes.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn [1] nil If we are at the end of the file.
+     * @cc.treturn [2] number The value of the byte read. This is returned when the {@code count} is absent.
+     * @cc.treturn [3] string The bytes read as a string. This is returned when the {@code count} is given.
+     */
+    @LuaFunction
+    public final Object[] read( Optional<Integer> countArg ) throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // read
-                checkOpen();
-                try
-                {
-                    if( args.length > 0 && args[0] != null )
-                    {
-                        int count = getInt( args, 0 );
-                        if( count < 0 )
-                        {
-                            throw new LuaException( "Cannot read a negative number of bytes" );
-                        }
-                        else if( count == 0 && m_seekable != null )
-                        {
-                            return m_seekable.position() >= m_seekable.size() ? null : new Object[] { "" };
-                        }
-
-                        if( count <= BUFFER_SIZE )
-                        {
-                            ByteBuffer buffer = ByteBuffer.allocate( count );
-
-                            int read = m_reader.read( buffer );
-                            if( read < 0 ) return null;
-                            return new Object[] { read < count ? Arrays.copyOf( buffer.array(), read ) : buffer.array() };
-                        }
-                        else
-                        {
-                            // Read the initial set of characters, failing if none are read.
-                            ByteBuffer buffer = ByteBuffer.allocate( BUFFER_SIZE );
-                            int read = m_reader.read( buffer );
-                            if( read < 0 ) return null;
-
-                            // If we failed to read "enough" here, let's just abort
-                            if( read >= count || read < BUFFER_SIZE )
-                            {
-                                return new Object[] { Arrays.copyOf( buffer.array(), read ) };
-                            }
-
-                            // Build up an array of ByteBuffers. Hopefully this means we can perform less allocation
-                            // than doubling up the buffer each time.
-                            int totalRead = read;
-                            List<ByteBuffer> parts = new ArrayList<>( 4 );
-                            parts.add( buffer );
-                            while( read >= BUFFER_SIZE && totalRead < count )
-                            {
-                                buffer = ByteBuffer.allocate( Math.min( BUFFER_SIZE, count - totalRead ) );
-                                read = m_reader.read( buffer );
-                                if( read < 0 ) break;
-
-                                totalRead += read;
-                                parts.add( buffer );
-                            }
-
-                            // Now just copy all the bytes across!
-                            byte[] bytes = new byte[totalRead];
-                            int pos = 0;
-                            for( ByteBuffer part : parts )
-                            {
-                                System.arraycopy( part.array(), 0, bytes, pos, part.position() );
-                                pos += part.position();
-                            }
-                            return new Object[] { bytes };
-                        }
-                    }
-                    else
-                    {
-                        single.clear();
-                        int b = m_reader.read( single );
-                        return b == -1 ? null : new Object[] { single.get( 0 ) & 0xFF };
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 1: // readAll
-                checkOpen();
-                try
-                {
-                    int expected = 32;
-                    if( m_seekable != null )
-                    {
-                        expected = Math.max( expected, (int) (m_seekable.size() - m_seekable.position()) );
-                    }
-                    ByteArrayOutputStream stream = new ByteArrayOutputStream( expected );
-
-                    ByteBuffer buf = ByteBuffer.allocate( 8192 );
-                    boolean readAnything = false;
-                    while( true )
-                    {
-                        buf.clear();
-                        int r = m_reader.read( buf );
-                        if( r == -1 ) break;
-
-                        readAnything = true;
-                        stream.write( buf.array(), 0, r );
-                    }
-                    return readAnything ? new Object[] { stream.toByteArray() } : null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // readLine
+            if( countArg.isPresent() )
             {
-                checkOpen();
-                boolean withTrailing = optBoolean( args, 0, false );
-                try
+                int count = countArg.get();
+                if( count < 0 ) throw new LuaException( "Cannot read a negative number of bytes" );
+                if( count == 0 && seekable != null )
                 {
-                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
-
-                    boolean readAnything = false, readRc = false;
-                    while( true )
-                    {
-                        single.clear();
-                        int read = m_reader.read( single );
-                        if( read <= 0 )
-                        {
-                            // Nothing else to read, and we saw no \n. Return the array. If we saw a \r, then add it
-                            // back.
-                            if( readRc ) stream.write( '\r' );
-                            return readAnything ? new Object[] { stream.toByteArray() } : null;
-                        }
-
-                        readAnything = true;
-
-                        byte chr = single.get( 0 );
-                        if( chr == '\n' )
-                        {
-                            if( withTrailing )
-                            {
-                                if( readRc ) stream.write( '\r' );
-                                stream.write( chr );
-                            }
-                            return new Object[] { stream.toByteArray() };
-                        }
-                        else
-                        {
-                            // We want to skip \r\n, but obviously need to include cases where \r is not followed by \n.
-                            // Note, this behaviour is non-standard compliant (strictly speaking we should have no
-                            // special logic for \r), but we preserve compatibility with EncodedReadableHandle and
-                            // previous behaviour of the io library.
-                            if( readRc ) stream.write( '\r' );
-                            readRc = chr == '\r';
-                            if( !readRc ) stream.write( chr );
-                        }
-                    }
+                    return seekable.position() >= seekable.size() ? null : new Object[] { "" };
                 }
-                catch( IOException e )
+
+                if( count <= BUFFER_SIZE )
                 {
-                    return null;
+                    ByteBuffer buffer = ByteBuffer.allocate( count );
+
+                    int read = reader.read( buffer );
+                    if( read < 0 ) return null;
+                    buffer.flip();
+                    return new Object[] { buffer };
+                }
+                else
+                {
+                    // Read the initial set of characters, failing if none are read.
+                    ByteBuffer buffer = ByteBuffer.allocate( BUFFER_SIZE );
+                    int read = reader.read( buffer );
+                    if( read < 0 ) return null;
+
+                    // If we failed to read "enough" here, let's just abort
+                    if( read >= count || read < BUFFER_SIZE )
+                    {
+                        buffer.flip();
+                        return new Object[] { buffer };
+                    }
+
+                    // Build up an array of ByteBuffers. Hopefully this means we can perform less allocation
+                    // than doubling up the buffer each time.
+                    int totalRead = read;
+                    List<ByteBuffer> parts = new ArrayList<>( 4 );
+                    parts.add( buffer );
+                    while( read >= BUFFER_SIZE && totalRead < count )
+                    {
+                        buffer = ByteBuffer.allocate( Math.min( BUFFER_SIZE, count - totalRead ) );
+                        read = reader.read( buffer );
+                        if( read < 0 ) break;
+
+                        totalRead += read;
+                        parts.add( buffer );
+                    }
+
+                    // Now just copy all the bytes across!
+                    byte[] bytes = new byte[totalRead];
+                    int pos = 0;
+                    for( ByteBuffer part : parts )
+                    {
+                        System.arraycopy( part.array(), 0, bytes, pos, part.position() );
+                        pos += part.position();
+                    }
+                    return new Object[] { bytes };
                 }
             }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            case 4: // seek
-                checkOpen();
-                return handleSeek( m_seekable, args );
-            default:
-                return null;
+            else
+            {
+                single.clear();
+                int b = reader.read( single );
+                return b == -1 ? null : new Object[] { single.get( 0 ) & 0xFF };
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    /**
+     * Read the remainder of the file.
+     *
+     * @return The file, or {@code null} if at the end of it.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn string|nil The remaining contents of the file, or {@code nil} if we are at the end.
+     */
+    @LuaFunction
+    public final Object[] readAll() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            int expected = 32;
+            if( seekable != null ) expected = Math.max( expected, (int) (seekable.size() - seekable.position()) );
+            ByteArrayOutputStream stream = new ByteArrayOutputStream( expected );
+
+            ByteBuffer buf = ByteBuffer.allocate( 8192 );
+            boolean readAnything = false;
+            while( true )
+            {
+                buf.clear();
+                int r = reader.read( buf );
+                if( r == -1 ) break;
+
+                readAnything = true;
+                stream.write( buf.array(), 0, r );
+            }
+            return readAnything ? new Object[] { stream.toByteArray() } : null;
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    /**
+     * Read a line from the file.
+     *
+     * @param withTrailingArg Whether to include the newline characters with the returned string. Defaults to {@code false}.
+     * @return The read string.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn string|nil The read line or {@code nil} if at the end of the file.
+     */
+    @LuaFunction
+    public final Object[] readLine( Optional<Boolean> withTrailingArg ) throws LuaException
+    {
+        checkOpen();
+        boolean withTrailing = withTrailingArg.orElse( false );
+        try
+        {
+            ByteArrayOutputStream stream = new ByteArrayOutputStream();
+
+            boolean readAnything = false, readRc = false;
+            while( true )
+            {
+                single.clear();
+                int read = reader.read( single );
+                if( read <= 0 )
+                {
+                    // Nothing else to read, and we saw no \n. Return the array. If we saw a \r, then add it
+                    // back.
+                    if( readRc ) stream.write( '\r' );
+                    return readAnything ? new Object[] { stream.toByteArray() } : null;
+                }
+
+                readAnything = true;
+
+                byte chr = single.get( 0 );
+                if( chr == '\n' )
+                {
+                    if( withTrailing )
+                    {
+                        if( readRc ) stream.write( '\r' );
+                        stream.write( chr );
+                    }
+                    return new Object[] { stream.toByteArray() };
+                }
+                else
+                {
+                    // We want to skip \r\n, but obviously need to include cases where \r is not followed by \n.
+                    // Note, this behaviour is non-standard compliant (strictly speaking we should have no
+                    // special logic for \r), but we preserve compatibility with EncodedReadableHandle and
+                    // previous behaviour of the io library.
+                    if( readRc ) stream.write( '\r' );
+                    readRc = chr == '\r';
+                    if( !readRc ) stream.write( chr );
+                }
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    public static class Seekable extends BinaryReadableHandle
+    {
+        Seekable( SeekableByteChannel seekable, Closeable closeable )
+        {
+            super( seekable, seekable, closeable );
+        }
+
+        /**
+         * Seek to a new position within the file, changing where bytes are written to. The new position is an offset
+         * given by {@code offset}, relative to a start position determined by {@code whence}:
+         *
+         * - {@code "set"}: {@code offset} is relative to the beginning of the file.
+         * - {@code "cur"}: Relative to the current position. This is the default.
+         * - {@code "end"}: Relative to the end of the file.
+         *
+         * In case of success, {@code seek} returns the new file position from the beginning of the file.
+         *
+         * @param whence Where the offset is relative to.
+         * @param offset The offset to seek to.
+         * @return The new position.
+         * @throws LuaException If the file has been closed.
+         * @cc.treturn [1] number The new position.
+         * @cc.treturn [2] nil If seeking failed.
+         * @cc.treturn string The reason seeking failed.
+         */
+        @LuaFunction
+        public final Object[] seek( Optional<String> whence, Optional<Long> offset ) throws LuaException
+        {
+            checkOpen();
+            return handleSeek( seekable, whence, offset );
         }
     }
 }

src/main/java/dan200/computercraft/core/apis/handles/BinaryWritableHandle.java

@@ -5,103 +5,137 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import com.google.common.collect.ObjectArrays;
-import dan200.computercraft.api.lua.ArgumentHelper;
-import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.shared.util.StringUtil;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.api.lua.LuaValues;
 
-import javax.annotation.Nonnull;
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.util.Optional;
 
+/**
+ * A file handle opened by {@link dan200.computercraft.core.apis.FSAPI#open} using the {@code "wb"} or {@code "ab"}
+ * modes.
+ *
+ * @cc.module fs.BinaryWriteHandle
+ */
 public class BinaryWritableHandle extends HandleGeneric
 {
-    private static final String[] METHOD_NAMES = new String[] { "write", "flush", "close" };
-    private static final String[] METHOD_SEEK_NAMES = ObjectArrays.concat( METHOD_NAMES, new String[] { "seek" }, String.class );
-
-    private final WritableByteChannel m_writer;
-    private final SeekableByteChannel m_seekable;
+    private final WritableByteChannel writer;
+    final SeekableByteChannel seekable;
     private final ByteBuffer single = ByteBuffer.allocate( 1 );
 
-    public BinaryWritableHandle( WritableByteChannel channel, Closeable closeable )
+    protected BinaryWritableHandle( WritableByteChannel writer, SeekableByteChannel seekable, Closeable closeable )
     {
         super( closeable );
-        m_writer = channel;
-        m_seekable = asSeekable( channel );
+        this.writer = writer;
+        this.seekable = seekable;
     }
 
-    public BinaryWritableHandle( WritableByteChannel channel )
+    public static BinaryWritableHandle of( WritableByteChannel channel, Closeable closeable )
     {
-        this( channel, channel );
+        SeekableByteChannel seekable = asSeekable( channel );
+        return seekable == null ? new BinaryWritableHandle( channel, null, closeable ) : new Seekable( seekable, closeable );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    public static BinaryWritableHandle of( WritableByteChannel channel )
     {
-        return m_seekable == null ? METHOD_NAMES : METHOD_SEEK_NAMES;
+        return of( channel, channel );
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    /**
+     * Write a string or byte to the file.
+     *
+     * @param arguments The value to write.
+     * @throws LuaException If the file has been closed.
+     * @cc.tparam [1] number The byte to write.
+     * @cc.tparam [2] string The string to write.
+     */
+    @LuaFunction
+    public final void write( IArguments arguments ) throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // write
-                checkOpen();
-                try
-                {
-                    if( args.length > 0 && args[0] instanceof Number )
-                    {
-                        int number = ((Number) args[0]).intValue();
-                        single.clear();
-                        single.put( (byte) number );
-                        single.flip();
+            Object arg = arguments.get( 0 );
+            if( arg instanceof Number )
+            {
+                int number = ((Number) arg).intValue();
+                single.clear();
+                single.put( (byte) number );
+                single.flip();
 
-                        m_writer.write( single );
-                    }
-                    else if( args.length > 0 && args[0] instanceof String )
-                    {
-                        String value = (String) args[0];
-                        m_writer.write( ByteBuffer.wrap( StringUtil.encodeString( value ) ) );
-                    }
-                    else
-                    {
-                        throw ArgumentHelper.badArgumentOf( 0, "string or number", args.length > 0 ? args[0] : null );
-                    }
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            case 1: // flush
-                checkOpen();
-                try
-                {
-                    // Technically this is not needed
-                    if( m_writer instanceof FileChannel ) ((FileChannel) m_writer).force( false );
+                writer.write( single );
+            }
+            else if( arg instanceof String )
+            {
+                writer.write( arguments.getBytes( 0 ) );
+            }
+            else
+            {
+                throw LuaValues.badArgumentOf( 0, "string or number", arg );
+            }
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
 
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // close
-                checkOpen();
-                close();
-                return null;
-            case 3: // seek
-                checkOpen();
-                return handleSeek( m_seekable, args );
-            default:
-                return null;
+    /**
+     * Save the current file without closing it.
+     *
+     * @throws LuaException If the file has been closed.
+     */
+    @LuaFunction
+    public final void flush() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            // Technically this is not needed
+            if( writer instanceof FileChannel ) ((FileChannel) writer).force( false );
+        }
+        catch( IOException ignored )
+        {
+        }
+    }
+
+    public static class Seekable extends BinaryWritableHandle
+    {
+        public Seekable( SeekableByteChannel seekable, Closeable closeable )
+        {
+            super( seekable, seekable, closeable );
+        }
+
+        /**
+         * Seek to a new position within the file, changing where bytes are written to. The new position is an offset
+         * given by {@code offset}, relative to a start position determined by {@code whence}:
+         *
+         * - {@code "set"}: {@code offset} is relative to the beginning of the file.
+         * - {@code "cur"}: Relative to the current position. This is the default.
+         * - {@code "end"}: Relative to the end of the file.
+         *
+         * In case of success, {@code seek} returns the new file position from the beginning of the file.
+         *
+         * @param whence Where the offset is relative to.
+         * @param offset The offset to seek to.
+         * @return The new position.
+         * @throws LuaException If the file has been closed.
+         * @cc.treturn [1] number The new position.
+         * @cc.treturn [2] nil If seeking failed.
+         * @cc.treturn string The reason seeking failed.
+         */
+        @LuaFunction
+        public final Object[] seek( Optional<String> whence, Optional<Long> offset ) throws LuaException
+        {
+            checkOpen();
+            return handleSeek( seekable, whence, offset );
         }
     }
 }

src/main/java/dan200/computercraft/core/apis/handles/EncodedReadableHandle.java

@@ -5,8 +5,8 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 
 import javax.annotation.Nonnull;
 import java.io.BufferedReader;
@@ -18,20 +18,24 @@ import java.nio.charset.Charset;
 import java.nio.charset.CharsetDecoder;
 import java.nio.charset.CodingErrorAction;
 import java.nio.charset.StandardCharsets;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.optBoolean;
-import static dan200.computercraft.api.lua.ArgumentHelper.optInt;
-
+/**
+ * A file handle opened with {@link dan200.computercraft.core.apis.FSAPI#open(String, String)} with the {@code "r"}
+ * mode.
+ *
+ * @cc.module fs.ReadHandle
+ */
 public class EncodedReadableHandle extends HandleGeneric
 {
     private static final int BUFFER_SIZE = 8192;
 
-    private BufferedReader m_reader;
+    private final BufferedReader reader;
 
     public EncodedReadableHandle( @Nonnull BufferedReader reader, @Nonnull Closeable closable )
     {
         super( closable );
-        m_reader = reader;
+        this.reader = reader;
     }
 
     public EncodedReadableHandle( @Nonnull BufferedReader reader )
@@ -39,123 +43,131 @@ public class EncodedReadableHandle extends HandleGeneric
         this( reader, reader );
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    /**
+     * Read a line from the file.
+     *
+     * @param withTrailingArg Whether to include the newline characters with the returned string. Defaults to {@code false}.
+     * @return The read string.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn string|nil The read line or {@code nil} if at the end of the file.
+     */
+    @LuaFunction
+    public final Object[] readLine( Optional<Boolean> withTrailingArg ) throws LuaException
     {
-        return new String[] {
-            "readLine",
-            "readAll",
-            "read",
-            "close",
-        };
+        checkOpen();
+        boolean withTrailing = withTrailingArg.orElse( false );
+        try
+        {
+            String line = reader.readLine();
+            if( line != null )
+            {
+                // While this is technically inaccurate, it's better than nothing
+                if( withTrailing ) line += "\n";
+                return new Object[] { line };
+            }
+            else
+            {
+                return null;
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
     }
 
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
+    /**
+     * Read the remainder of the file.
+     *
+     * @return The file, or {@code null} if at the end of it.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn nil|string The remaining contents of the file, or {@code nil} if we are at the end.
+     */
+    @LuaFunction
+    public final Object[] readAll() throws LuaException
     {
-        switch( method )
+        checkOpen();
+        try
         {
-            case 0: // readLine
+            StringBuilder result = new StringBuilder();
+            String line = reader.readLine();
+            while( line != null )
             {
-                checkOpen();
-                boolean withTrailing = optBoolean( args, 0, false );
-                try
+                result.append( line );
+                line = reader.readLine();
+                if( line != null )
                 {
-                    String line = m_reader.readLine();
-                    if( line != null )
-                    {
-                        // While this is technically inaccurate, it's better than nothing
-                        if( withTrailing ) line += "\n";
-                        return new Object[] { line };
-                    }
-                    else
-                    {
-                        return null;
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
+                    result.append( "\n" );
                 }
             }
-            case 1: // readAll
-                checkOpen();
-                try
+            return new Object[] { result.toString() };
+        }
+        catch( IOException e )
+        {
+            return null;
+        }
+    }
+
+    /**
+     * Read a number of characters from this file.
+     *
+     * @param countA The number of characters to read, defaulting to 1.
+     * @return The read characters.
+     * @throws LuaException When trying to read a negative number of characters.
+     * @throws LuaException If the file has been closed.
+     * @cc.treturn string|nil The read characters, or {@code nil} if at the of the file.
+     */
+    @LuaFunction
+    public final Object[] read( Optional<Integer> countA ) throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            int count = countA.orElse( 1 );
+            if( count < 0 )
+            {
+                // Whilst this may seem absurd to allow reading 0 characters, PUC Lua it so
+                // it seems best to remain somewhat consistent.
+                throw new LuaException( "Cannot read a negative number of characters" );
+            }
+            else if( count <= BUFFER_SIZE )
+            {
+                // If we've got a small count, then allocate that and read it.
+                char[] chars = new char[count];
+                int read = reader.read( chars );
+
+                return read < 0 ? null : new Object[] { new String( chars, 0, read ) };
+            }
+            else
+            {
+                // If we've got a large count, read in bunches of 8192.
+                char[] buffer = new char[BUFFER_SIZE];
+
+                // Read the initial set of characters, failing if none are read.
+                int read = reader.read( buffer, 0, Math.min( buffer.length, count ) );
+                if( read < 0 ) return null;
+
+                StringBuilder out = new StringBuilder( read );
+                int totalRead = read;
+                out.append( buffer, 0, read );
+
+                // Otherwise read until we either reach the limit or we no longer consume
+                // the full buffer.
+                while( read >= BUFFER_SIZE && totalRead < count )
                 {
-                    StringBuilder result = new StringBuilder();
-                    String line = m_reader.readLine();
-                    while( line != null )
-                    {
-                        result.append( line );
-                        line = m_reader.readLine();
-                        if( line != null )
-                        {
-                            result.append( "\n" );
-                        }
-                    }
-                    return new Object[] { result.toString() };
+                    read = reader.read( buffer, 0, Math.min( BUFFER_SIZE, count - totalRead ) );
+                    if( read < 0 ) break;
+
+                    totalRead += read;
+                    out.append( buffer, 0, read );
                 }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 2: // read
-                checkOpen();
-                try
-                {
-                    int count = optInt( args, 0, 1 );
-                    if( count < 0 )
-                    {
-                        // Whilst this may seem absurd to allow reading 0 characters, PUC Lua it so
-                        // it seems best to remain somewhat consistent.
-                        throw new LuaException( "Cannot read a negative number of characters" );
-                    }
-                    else if( count <= BUFFER_SIZE )
-                    {
-                        // If we've got a small count, then allocate that and read it.
-                        char[] chars = new char[count];
-                        int read = m_reader.read( chars );
 
-                        return read < 0 ? null : new Object[] { new String( chars, 0, read ) };
-                    }
-                    else
-                    {
-                        // If we've got a large count, read in bunches of 8192.
-                        char[] buffer = new char[BUFFER_SIZE];
-
-                        // Read the initial set of characters, failing if none are read.
-                        int read = m_reader.read( buffer, 0, Math.min( buffer.length, count ) );
-                        if( read < 0 ) return null;
-
-                        StringBuilder out = new StringBuilder( read );
-                        int totalRead = read;
-                        out.append( buffer, 0, read );
-
-                        // Otherwise read until we either reach the limit or we no longer consume
-                        // the full buffer.
-                        while( read >= BUFFER_SIZE && totalRead < count )
-                        {
-                            read = m_reader.read( buffer, 0, Math.min( BUFFER_SIZE, count - totalRead ) );
-                            if( read < 0 ) break;
-
-                            totalRead += read;
-                            out.append( buffer, 0, read );
-                        }
-
-                        return new Object[] { out.toString() };
-                    }
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            default:
-                return null;
+                return new Object[] { out.toString() };
+            }
+        }
+        catch( IOException e )
+        {
+            return null;
         }
     }
 

src/main/java/dan200/computercraft/core/apis/handles/EncodedWritableHandle.java

@@ -5,8 +5,10 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.shared.util.StringUtil;
 
 import javax.annotation.Nonnull;
 import java.io.BufferedWriter;
@@ -19,87 +21,83 @@ import java.nio.charset.CharsetEncoder;
 import java.nio.charset.CodingErrorAction;
 import java.nio.charset.StandardCharsets;
 
+/**
+ * A file handle opened by {@link dan200.computercraft.core.apis.FSAPI#open} using the {@code "w"} or {@code "a"} modes.
+ *
+ * @cc.module fs.WriteHandle
+ */
 public class EncodedWritableHandle extends HandleGeneric
 {
-    private BufferedWriter m_writer;
+    private final BufferedWriter writer;
 
     public EncodedWritableHandle( @Nonnull BufferedWriter writer, @Nonnull Closeable closable )
     {
         super( closable );
-        m_writer = writer;
+        this.writer = writer;
     }
 
-    public EncodedWritableHandle( @Nonnull BufferedWriter writer )
+    /**
+     * Write a string of characters to the file.
+     *
+     * @param args The value to write.
+     * @throws LuaException If the file has been closed.
+     * @cc.param The value to write to the file.
+     */
+    @LuaFunction
+    public final void write( IArguments args ) throws LuaException
     {
-        this( writer, writer );
-    }
-
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
-    {
-        return new String[] {
-            "write",
-            "writeLine",
-            "flush",
-            "close",
-        };
-    }
-
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
-    {
-        switch( method )
+        checkOpen();
+        String text = StringUtil.toString( args.get( 0 ) );
+        try
         {
-            case 0: // write
-            {
-                checkOpen();
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                try
-                {
-                    m_writer.write( text, 0, text.length() );
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 1: // writeLine
-            {
-                checkOpen();
-                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
-                try
-                {
-                    m_writer.write( text, 0, text.length() );
-                    m_writer.newLine();
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    throw new LuaException( e.getMessage() );
-                }
-            }
-            case 2: // flush
-                checkOpen();
-                try
-                {
-                    m_writer.flush();
-                    return null;
-                }
-                catch( IOException e )
-                {
-                    return null;
-                }
-            case 3: // close
-                checkOpen();
-                close();
-                return null;
-            default:
-                return null;
+            writer.write( text, 0, text.length() );
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
         }
     }
 
+    /**
+     * Write a string of characters to the file, follwing them with a new line character.
+     *
+     * @param args The value to write.
+     * @throws LuaException If the file has been closed.
+     * @cc.param The value to write to the file.
+     */
+    @LuaFunction
+    public final void writeLine( IArguments args ) throws LuaException
+    {
+        checkOpen();
+        String text = StringUtil.toString( args.get( 0 ) );
+        try
+        {
+            writer.write( text, 0, text.length() );
+            writer.newLine();
+        }
+        catch( IOException e )
+        {
+            throw new LuaException( e.getMessage() );
+        }
+    }
+
+    /**
+     * Save the current file without closing it.
+     *
+     * @throws LuaException If the file has been closed.
+     */
+    @LuaFunction
+    public final void flush() throws LuaException
+    {
+        checkOpen();
+        try
+        {
+            writer.flush();
+        }
+        catch( IOException ignored )
+        {
+        }
+    }
 
     public static BufferedWriter openUtf8( WritableByteChannel channel )
     {

src/main/java/dan200/computercraft/core/apis/handles/HandleGeneric.java

@@ -5,8 +5,8 @@
  */
 package dan200.computercraft.core.apis.handles;
 
-import dan200.computercraft.api.lua.ILuaObject;
 import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.shared.util.IoUtil;
 
 import javax.annotation.Nonnull;
@@ -14,62 +14,71 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.nio.channels.Channel;
 import java.nio.channels.SeekableByteChannel;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.optLong;
-import static dan200.computercraft.api.lua.ArgumentHelper.optString;
-
-public abstract class HandleGeneric implements ILuaObject
+public abstract class HandleGeneric
 {
-    private Closeable m_closable;
-    private boolean m_open = true;
+    private Closeable closable;
+    private boolean open = true;
 
     protected HandleGeneric( @Nonnull Closeable closable )
     {
-        m_closable = closable;
+        this.closable = closable;
     }
 
     protected void checkOpen() throws LuaException
     {
-        if( !m_open ) throw new LuaException( "attempt to use a closed file" );
+        if( !open ) throw new LuaException( "attempt to use a closed file" );
     }
 
     protected final void close()
     {
-        m_open = false;
+        open = false;
 
-        Closeable closeable = m_closable;
-        if( closeable != null )
-        {
-            IoUtil.closeQuietly( closeable );
-            m_closable = null;
-        }
+        IoUtil.closeQuietly( closable );
+        closable = null;
     }
 
+    /**
+     * Close this file, freeing any resources it uses.
+     *
+     * Once a file is closed it may no longer be read or written to.
+     *
+     * @throws LuaException If the file has already been closed.
+     */
+    @LuaFunction( "close" )
+    public final void doClose() throws LuaException
+    {
+        checkOpen();
+        close();
+    }
+
+
     /**
      * Shared implementation for various file handle types.
      *
      * @param channel The channel to seek in
-     * @param args    The Lua arguments to process, like Lua's {@code file:seek}.
+     * @param whence  The seeking mode.
+     * @param offset  The offset to seek to.
      * @return The new position of the file, or null if some error occurred.
      * @throws LuaException If the arguments were invalid
      * @see <a href="https://www.lua.org/manual/5.1/manual.html#pdf-file:seek">{@code file:seek} in the Lua manual.</a>
      */
-    protected static Object[] handleSeek( SeekableByteChannel channel, Object[] args ) throws LuaException
+    protected static Object[] handleSeek( SeekableByteChannel channel, Optional<String> whence, Optional<Long> offset ) throws LuaException
     {
+        long actualOffset = offset.orElse( 0L );
         try
         {
-            String whence = optString( args, 0, "cur" );
-            long offset = optLong( args, 1, 0 );
-            switch( whence )
+            switch( whence.orElse( "cur" ) )
             {
                 case "set":
-                    channel.position( offset );
+                    channel.position( actualOffset );
                     break;
                 case "cur":
-                    channel.position( channel.position() + offset );
+                    channel.position( channel.position() + actualOffset );
                     break;
                 case "end":
-                    channel.position( channel.size() + offset );
+                    channel.position( channel.size() + actualOffset );
                     break;
                 default:
                     throw new LuaException( "bad argument #1 to 'seek' (invalid option '" + whence + "'" );
@@ -79,7 +88,7 @@ public abstract class HandleGeneric implements ILuaObject
         }
         catch( IllegalArgumentException e )
         {
-            return new Object[] { false, "Position is negative" };
+            return new Object[] { null, "Position is negative" };
         }
         catch( IOException e )
         {

src/main/java/dan200/computercraft/core/apis/http/CheckUrl.java

@@ -7,6 +7,7 @@ package dan200.computercraft.core.apis.http;
 
 import dan200.computercraft.core.apis.IAPIEnvironment;
 
+import java.net.InetSocketAddress;
 import java.net.URI;
 import java.util.concurrent.Future;
 
@@ -46,12 +47,14 @@ public class CheckUrl extends Resource<CheckUrl>
 
         try
         {
-            NetworkUtils.getAddress( host, 80, false );
-            if( tryClose() ) environment.queueEvent( EVENT, new Object[] { address, true } );
+            InetSocketAddress netAddress = NetworkUtils.getAddress( host, 80, false );
+            NetworkUtils.getOptions( host, netAddress );
+
+            if( tryClose() ) environment.queueEvent( EVENT, address, true );
         }
         catch( HTTPRequestException e )
         {
-            if( tryClose() ) environment.queueEvent( EVENT, new Object[] { address, false, e.getMessage() } );
+            if( tryClose() ) environment.queueEvent( EVENT, address, false, e.getMessage() );
         }
     }
 

src/main/java/dan200/computercraft/core/apis/http/NetworkUtils.java

@@ -6,6 +6,9 @@
 package dan200.computercraft.core.apis.http;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.core.apis.http.options.Action;
+import dan200.computercraft.core.apis.http.options.AddressRule;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.shared.util.ThreadUtils;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.EventLoopGroup;
@@ -15,7 +18,6 @@ import io.netty.handler.ssl.SslContextBuilder;
 
 import javax.net.ssl.SSLException;
 import javax.net.ssl.TrustManagerFactory;
-import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.security.KeyStore;
 import java.util.concurrent.ExecutorService;
@@ -106,24 +108,31 @@ public final class NetworkUtils
      * @param port The port, or -1 if not defined.
      * @param ssl  Whether to connect with SSL. This is used to find the default port if not otherwise specified.
      * @return The resolved address.
-     * @throws HTTPRequestException If the host is not permitted.
+     * @throws HTTPRequestException If the host is not malformed.
      */
     public static InetSocketAddress getAddress( String host, int port, boolean ssl ) throws HTTPRequestException
     {
         if( port < 0 ) port = ssl ? 443 : 80;
-
         InetSocketAddress socketAddress = new InetSocketAddress( host, port );
         if( socketAddress.isUnresolved() ) throw new HTTPRequestException( "Unknown host" );
-
-        InetAddress address = socketAddress.getAddress();
-        if( AddressRule.apply( ComputerCraft.httpRules, host, address ) == AddressRule.Action.DENY )
-        {
-            throw new HTTPRequestException( "Domain not permitted" );
-        }
-
         return socketAddress;
     }
 
+    /**
+     * Get options for a specific domain.
+     *
+     * @param host    The host to resolve.
+     * @param address The address, resolved by {@link #getAddress(String, int, boolean)}.
+     * @return The options for this host.
+     * @throws HTTPRequestException If the host is not permitted
+     */
+    public static Options getOptions( String host, InetSocketAddress address ) throws HTTPRequestException
+    {
+        Options options = AddressRule.apply( ComputerCraft.httpRules, host, address.getAddress() );
+        if( options.action == Action.DENY ) throw new HTTPRequestException( "Domain not permitted" );
+        return options;
+    }
+
     /**
      * Read a {@link ByteBuf} into a byte array.
      *

src/main/java/dan200/computercraft/core/apis/http/Resource.java

@@ -106,7 +106,7 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
 
     protected static <T extends Closeable> T closeCloseable( T closeable )
     {
-        if( closeable != null ) IoUtil.closeQuietly( closeable );
+        IoUtil.closeQuietly( closeable );
         return null;
     }
 

src/main/java/dan200/computercraft/core/apis/http/options/Action.java

@@ -0,0 +1,23 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis.http.options;
+
+import javax.annotation.Nonnull;
+
+public enum Action
+{
+    ALLOW,
+    DENY;
+
+    private final PartialOptions partial = new PartialOptions( this, null, null, null, null );
+
+    @Nonnull
+    public PartialOptions toPartial()
+    {
+        return partial;
+    }
+}

src/main/java/dan200/computercraft/core/apis/http/options/AddressRule.java

@@ -3,11 +3,12 @@
  * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
  * Send enquiries to dratcliffe@gmail.com
  */
-package dan200.computercraft.core.apis.http;
+package dan200.computercraft.core.apis.http.options;
 
 import com.google.common.net.InetAddresses;
 import dan200.computercraft.ComputerCraft;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.net.Inet6Address;
 import java.net.InetAddress;
@@ -18,6 +19,11 @@ import java.util.regex.Pattern;
  */
 public final class AddressRule
 {
+    public static final long MAX_DOWNLOAD = 16 * 1024 * 1024;
+    public static final long MAX_UPLOAD = 4 * 1024 * 1024;
+    public static final int TIMEOUT = 30_000;
+    public static final int WEBSOCKET_MESSAGE = 128 * 1024;
+
     private static final class HostRange
     {
         private final byte[] min;
@@ -44,25 +50,19 @@ public final class AddressRule
         }
     }
 
-    public enum Action
-    {
-        ALLOW,
-        DENY,
-    }
-
     private final HostRange ip;
     private final Pattern domainPattern;
-    private final Action action;
+    private final PartialOptions partial;
 
-    private AddressRule( HostRange ip, Pattern domainPattern, Action action )
+    private AddressRule( @Nullable HostRange ip, @Nullable Pattern domainPattern, @Nonnull PartialOptions partial )
     {
         this.ip = ip;
         this.domainPattern = domainPattern;
-        this.action = action;
+        this.partial = partial;
     }
 
     @Nullable
-    public static AddressRule parse( String filter, Action action )
+    public static AddressRule parse( String filter, @Nonnull PartialOptions partial )
     {
         int cidr = filter.indexOf( '/' );
         if( cidr >= 0 )
@@ -117,12 +117,12 @@ public final class AddressRule
                 size -= 8;
             }
 
-            return new AddressRule( new HostRange( minBytes, maxBytes ), null, action );
+            return new AddressRule( new HostRange( minBytes, maxBytes ), null, partial );
         }
         else
         {
             Pattern pattern = Pattern.compile( "^\\Q" + filter.replaceAll( "\\*", "\\\\E.*\\\\Q" ) + "\\E$" );
-            return new AddressRule( null, pattern, action );
+            return new AddressRule( null, pattern, partial );
         }
     }
 
@@ -133,7 +133,7 @@ public final class AddressRule
      * @param address The address to check.
      * @return Whether it matches any of these patterns.
      */
-    public boolean matches( String domain, InetAddress address )
+    private boolean matches( String domain, InetAddress address )
     {
         if( domainPattern != null )
         {
@@ -155,13 +155,32 @@ public final class AddressRule
         return ip != null && ip.contains( address );
     }
 
-    public static Action apply( Iterable<? extends AddressRule> rules, String domain, InetAddress address )
+    public static Options apply( Iterable<? extends AddressRule> rules, String domain, InetAddress address )
     {
+        PartialOptions options = null;
+        boolean hasMany = false;
+
         for( AddressRule rule : rules )
         {
-            if( rule.matches( domain, address ) ) return rule.action;
+            if( !rule.matches( domain, address ) ) continue;
+
+            if( options == null )
+            {
+                options = rule.partial;
+            }
+            else
+            {
+
+                if( !hasMany )
+                {
+                    options = options.copy();
+                    hasMany = true;
+                }
+
+                options.merge( rule.partial );
+            }
         }
 
-        return Action.DENY;
+        return (options == null ? PartialOptions.DEFAULT : options).toOptions();
     }
 }

src/main/java/dan200/computercraft/core/apis/http/options/AddressRuleConfig.java

@@ -0,0 +1,132 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis.http.options;
+
+import com.electronwill.nightconfig.core.CommentedConfig;
+import com.electronwill.nightconfig.core.Config;
+import com.electronwill.nightconfig.core.InMemoryCommentedFormat;
+import com.electronwill.nightconfig.core.UnmodifiableConfig;
+import dan200.computercraft.ComputerCraft;
+
+import javax.annotation.Nullable;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Parses, checks and generates {@link Config}s for {@link AddressRule}.
+ */
+public class AddressRuleConfig
+{
+    public static UnmodifiableConfig makeRule( String host, Action action )
+    {
+        CommentedConfig config = InMemoryCommentedFormat.defaultInstance().createConfig( ConcurrentHashMap::new );
+        config.add( "host", host );
+        config.add( "action", action.name().toLowerCase( Locale.ROOT ) );
+
+        if( host.equals( "*" ) && action == Action.ALLOW )
+        {
+            config.setComment( "timeout", "The period of time (in milliseconds) to wait before a HTTP request times out. Set to 0 for unlimited." );
+            config.add( "timeout", AddressRule.TIMEOUT );
+
+            config.setComment( "max_download", "The maximum size (in bytes) that a computer can download in a single request. Note that responses may receive more data than allowed, but this data will not be returned to the client." );
+            config.set( "max_download", AddressRule.MAX_DOWNLOAD );
+
+            config.setComment( "max_upload", "The maximum size (in bytes) that a computer can upload in a single request. This includes headers and POST text." );
+            config.set( "max_upload", AddressRule.MAX_UPLOAD );
+
+            config.setComment( "max_websocket_message", "The maximum size (in bytes) that a computer can send or receive in one websocket packet." );
+            config.set( "max_websocket_message", AddressRule.WEBSOCKET_MESSAGE );
+        }
+
+        return config;
+    }
+
+    public static boolean checkRule( UnmodifiableConfig builder )
+    {
+        String hostObj = get( builder, "host", String.class ).orElse( null );
+        return hostObj != null && checkEnum( builder, "action", Action.class )
+            && check( builder, "timeout", Number.class )
+            && check( builder, "max_upload", Number.class )
+            && check( builder, "max_download", Number.class )
+            && check( builder, "websocket_message", Number.class )
+            && AddressRule.parse( hostObj, PartialOptions.DEFAULT ) != null;
+    }
+
+    @Nullable
+    public static AddressRule parseRule( UnmodifiableConfig builder )
+    {
+        String hostObj = get( builder, "host", String.class ).orElse( null );
+        if( hostObj == null ) return null;
+
+        Action action = getEnum( builder, "action", Action.class ).orElse( null );
+        Integer timeout = get( builder, "timeout", Number.class ).map( Number::intValue ).orElse( null );
+        Long maxUpload = get( builder, "max_upload", Number.class ).map( Number::longValue ).orElse( null );
+        Long maxDownload = get( builder, "max_download", Number.class ).map( Number::longValue ).orElse( null );
+        Integer websocketMessage = get( builder, "websocket_message", Number.class ).map( Number::intValue ).orElse( null );
+
+        PartialOptions options = new PartialOptions(
+            action,
+            maxUpload,
+            maxDownload,
+            timeout,
+            websocketMessage
+        );
+
+        return AddressRule.parse( hostObj, options );
+    }
+
+    private static <T> boolean check( UnmodifiableConfig config, String field, Class<T> klass )
+    {
+        Object value = config.get( field );
+        if( value == null || klass.isInstance( value ) ) return true;
+
+        ComputerCraft.log.warn( "HTTP rule's {} is not a {}.", field, klass.getSimpleName() );
+        return false;
+    }
+
+    private static <T extends Enum<T>> boolean checkEnum( UnmodifiableConfig config, String field, Class<T> klass )
+    {
+        Object value = config.get( field );
+        if( value == null ) return true;
+
+        if( !(value instanceof String) )
+        {
+            ComputerCraft.log.warn( "HTTP rule's {} is not a string", field );
+            return false;
+        }
+
+        if( parseEnum( klass, (String) value ) == null )
+        {
+            ComputerCraft.log.warn( "HTTP rule's {} is not a known option", field );
+            return false;
+        }
+
+        return true;
+    }
+
+    private static <T> Optional<T> get( UnmodifiableConfig config, String field, Class<T> klass )
+    {
+        Object value = config.get( field );
+        return klass.isInstance( value ) ? Optional.of( klass.cast( value ) ) : Optional.empty();
+    }
+
+    private static <T extends Enum<T>> Optional<T> getEnum( UnmodifiableConfig config, String field, Class<T> klass )
+    {
+        return get( config, field, String.class ).map( x -> parseEnum( klass, x ) );
+    }
+
+    @Nullable
+    private static <T extends Enum<T>> T parseEnum( Class<T> klass, String x )
+    {
+        for( T value : klass.getEnumConstants() )
+        {
+            if( value.name().equalsIgnoreCase( x ) ) return value;
+        }
+        return null;
+    }
+}

src/main/java/dan200/computercraft/core/apis/http/options/Options.java

@@ -0,0 +1,31 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis.http.options;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Options about a specific domain.
+ */
+public final class Options
+{
+    @Nonnull
+    public final Action action;
+    public final long maxUpload;
+    public final long maxDownload;
+    public final int timeout;
+    public final int websocketMessage;
+
+    Options( @Nonnull Action action, long maxUpload, long maxDownload, int timeout, int websocketMessage )
+    {
+        this.action = action;
+        this.maxUpload = maxUpload;
+        this.maxDownload = maxDownload;
+        this.timeout = timeout;
+        this.websocketMessage = websocketMessage;
+    }
+}

src/main/java/dan200/computercraft/core/apis/http/options/PartialOptions.java

@@ -0,0 +1,59 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2020. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis.http.options;
+
+import javax.annotation.Nonnull;
+
+public final class PartialOptions
+{
+    static final PartialOptions DEFAULT = new PartialOptions( null, null, null, null, null );
+
+    Action action;
+    Long maxUpload;
+    Long maxDownload;
+    Integer timeout;
+    Integer websocketMessage;
+
+    Options options;
+
+    PartialOptions( Action action, Long maxUpload, Long maxDownload, Integer timeout, Integer websocketMessage )
+    {
+        this.action = action;
+        this.maxUpload = maxUpload;
+        this.maxDownload = maxDownload;
+        this.timeout = timeout;
+        this.websocketMessage = websocketMessage;
+    }
+
+    @Nonnull
+    Options toOptions()
+    {
+        if( options != null ) return options;
+
+        return options = new Options(
+            action == null ? Action.DENY : action,
+            maxUpload == null ? AddressRule.MAX_UPLOAD : maxUpload,
+            maxDownload == null ? AddressRule.MAX_DOWNLOAD : maxDownload,
+            timeout == null ? AddressRule.TIMEOUT : timeout,
+            websocketMessage == null ? AddressRule.WEBSOCKET_MESSAGE : websocketMessage
+        );
+    }
+
+    void merge( @Nonnull PartialOptions other )
+    {
+        if( action == null && other.action != null ) action = other.action;
+        if( maxUpload == null && other.maxUpload != null ) maxUpload = other.maxUpload;
+        if( maxDownload == null && other.maxDownload != null ) maxDownload = other.maxDownload;
+        if( timeout == null && other.timeout != null ) timeout = other.timeout;
+        if( websocketMessage == null && other.websocketMessage != null ) websocketMessage = other.websocketMessage;
+    }
+
+    PartialOptions copy()
+    {
+        return new PartialOptions( action, maxUpload, maxDownload, timeout, websocketMessage );
+    }
+}

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequest.java

@@ -6,12 +6,12 @@
 package dan200.computercraft.core.apis.http.request;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.lua.ILuaObject;
 import dan200.computercraft.core.apis.IAPIEnvironment;
 import dan200.computercraft.core.apis.http.HTTPRequestException;
 import dan200.computercraft.core.apis.http.NetworkUtils;
 import dan200.computercraft.core.apis.http.Resource;
 import dan200.computercraft.core.apis.http.ResourceGroup;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.core.tracking.TrackingField;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.buffer.ByteBuf;
@@ -137,16 +137,24 @@ public class HttpRequest extends Resource<HttpRequest>
         {
             boolean ssl = uri.getScheme().equalsIgnoreCase( "https" );
             InetSocketAddress socketAddress = NetworkUtils.getAddress( uri.getHost(), uri.getPort(), ssl );
+            Options options = NetworkUtils.getOptions( uri.getHost(), socketAddress );
             SslContext sslContext = ssl ? NetworkUtils.getSslContext() : null;
 
             // getAddress may have a slight delay, so let's perform another cancellation check.
             if( isClosed() ) return;
 
+            long requestBody = getHeaderSize( headers ) + postBuffer.capacity();
+            if( options.maxUpload != 0 && requestBody > options.maxUpload )
+            {
+                failure( "Request body is too large" );
+                return;
+            }
+
             // Add request size to the tracker before opening the connection
             environment.addTrackingChange( TrackingField.HTTP_REQUESTS, 1 );
-            environment.addTrackingChange( TrackingField.HTTP_UPLOAD, getHeaderSize( headers ) + postBuffer.capacity() );
+            environment.addTrackingChange( TrackingField.HTTP_UPLOAD, requestBody );
 
-            HttpRequestHandler handler = currentRequest = new HttpRequestHandler( this, uri, method );
+            HttpRequestHandler handler = currentRequest = new HttpRequestHandler( this, uri, method, options );
             connectFuture = new Bootstrap()
                 .group( NetworkUtils.LOOP_GROUP )
                 .channelFactory( NioSocketChannel::new )
@@ -156,9 +164,9 @@ public class HttpRequest extends Resource<HttpRequest>
                     protected void initChannel( SocketChannel ch )
                     {
 
-                        if( ComputerCraft.httpTimeout > 0 )
+                        if( options.timeout > 0 )
                         {
-                            ch.config().setConnectTimeoutMillis( ComputerCraft.httpTimeout );
+                            ch.config().setConnectTimeoutMillis( options.timeout );
                         }
 
                         ChannelPipeline p = ch.pipeline();
@@ -167,9 +175,9 @@ public class HttpRequest extends Resource<HttpRequest>
                             p.addLast( sslContext.newHandler( ch.alloc(), uri.getHost(), socketAddress.getPort() ) );
                         }
 
-                        if( ComputerCraft.httpTimeout > 0 )
+                        if( options.timeout > 0 )
                         {
-                            p.addLast( new ReadTimeoutHandler( ComputerCraft.httpTimeout, TimeUnit.MILLISECONDS ) );
+                            p.addLast( new ReadTimeoutHandler( options.timeout, TimeUnit.MILLISECONDS ) );
                         }
 
                         p.addLast(
@@ -195,13 +203,13 @@ public class HttpRequest extends Resource<HttpRequest>
         catch( Exception e )
         {
             failure( "Could not connect" );
-            if( ComputerCraft.logPeripheralErrors ) ComputerCraft.log.error( "Error in HTTP request", e );
+            if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in HTTP request", e );
         }
     }
 
     void failure( String message )
     {
-        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, new Object[] { address, message } );
+        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message );
     }
 
     void failure( Throwable cause )
@@ -227,14 +235,14 @@ public class HttpRequest extends Resource<HttpRequest>
         failure( message );
     }
 
-    void failure( String message, ILuaObject object )
+    void failure( String message, HttpResponseHandle object )
     {
-        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, new Object[] { address, message, object } );
+        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message, object );
     }
 
-    void success( ILuaObject object )
+    void success( HttpResponseHandle object )
     {
-        if( tryClose() ) environment.queueEvent( SUCCESS_EVENT, new Object[] { address, object } );
+        if( tryClose() ) environment.queueEvent( SUCCESS_EVENT, address, object );
     }
 
     @Override

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequestHandler.java

@@ -6,12 +6,13 @@
 package dan200.computercraft.core.apis.http.request;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.lua.ILuaObject;
 import dan200.computercraft.core.apis.handles.ArrayByteChannel;
 import dan200.computercraft.core.apis.handles.BinaryReadableHandle;
 import dan200.computercraft.core.apis.handles.EncodedReadableHandle;
+import dan200.computercraft.core.apis.handles.HandleGeneric;
 import dan200.computercraft.core.apis.http.HTTPRequestException;
 import dan200.computercraft.core.apis.http.NetworkUtils;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.core.tracking.TrackingField;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.CompositeByteBuf;
@@ -45,18 +46,20 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
 
     private final URI uri;
     private final HttpMethod method;
+    private final Options options;
 
     private Charset responseCharset;
     private final HttpHeaders responseHeaders = new DefaultHttpHeaders();
     private HttpResponseStatus responseStatus;
     private CompositeByteBuf responseBody;
 
-    HttpRequestHandler( HttpRequest request, URI uri, HttpMethod method )
+    HttpRequestHandler( HttpRequest request, URI uri, HttpMethod method, Options options )
     {
         this.request = request;
 
         this.uri = uri;
         this.method = method;
+        this.options = options;
     }
 
     @Override
@@ -81,9 +84,9 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
         }
         if( !request.headers().contains( HttpHeaderNames.USER_AGENT ) )
         {
-            request.headers().set( HttpHeaderNames.USER_AGENT, ComputerCraft.MOD_ID + "/" + ComputerCraft.getVersion() );
+            request.headers().set( HttpHeaderNames.USER_AGENT, this.request.environment().getComputerEnvironment().getUserAgent() );
         }
-        request.headers().set( HttpHeaderNames.HOST, uri.getHost() );
+        request.headers().set( HttpHeaderNames.HOST, uri.getPort() < 0 ? uri.getHost() : uri.getHost() + ":" + uri.getPort() );
         request.headers().set( HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE );
 
         ctx.channel().writeAndFlush( request );
@@ -153,7 +156,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
             if( partial.isReadable() )
             {
                 // If we've read more than we're allowed to handle, abort as soon as possible.
-                if( ComputerCraft.httpMaxDownload != 0 && responseBody.readableBytes() + partial.readableBytes() > ComputerCraft.httpMaxDownload )
+                if( options.maxDownload != 0 && responseBody.readableBytes() + partial.readableBytes() > options.maxDownload )
                 {
                     closed = true;
                     ctx.close();
@@ -185,7 +188,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
     @Override
     public void exceptionCaught( ChannelHandlerContext ctx, Throwable cause )
     {
-        if( ComputerCraft.logPeripheralErrors ) ComputerCraft.log.error( "Error handling HTTP response", cause );
+        if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error handling HTTP response", cause );
         request.failure( cause );
     }
 
@@ -209,10 +212,10 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
 
         // Prepare to queue an event
         ArrayByteChannel contents = new ArrayByteChannel( bytes );
-        final ILuaObject reader = request.isBinary()
-            ? new BinaryReadableHandle( contents )
+        HandleGeneric reader = request.isBinary()
+            ? BinaryReadableHandle.of( contents )
             : new EncodedReadableHandle( EncodedReadableHandle.open( contents, responseCharset ) );
-        ILuaObject stream = new HttpResponseHandle( reader, status.code(), status.reasonPhrase(), headers );
+        HttpResponseHandle stream = new HttpResponseHandle( reader, status.code(), status.reasonPhrase(), headers );
 
         if( status.code() >= 200 && status.code() < 400 )
         {

src/main/java/dan200/computercraft/core/apis/http/request/HttpResponseHandle.java

@@ -5,62 +5,81 @@
  */
 package dan200.computercraft.core.apis.http.request;
 
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.ILuaObject;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.IArguments;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.core.apis.HTTPAPI;
+import dan200.computercraft.core.apis.handles.BinaryReadableHandle;
+import dan200.computercraft.core.apis.handles.EncodedReadableHandle;
+import dan200.computercraft.core.apis.handles.HandleGeneric;
+import dan200.computercraft.core.asm.ObjectSource;
 
 import javax.annotation.Nonnull;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.Map;
 
 /**
- * Wraps a {@link dan200.computercraft.core.apis.handles.HandleGeneric} and provides additional methods for
- * getting the response code and headers.
+ * A http response. This provides the same methods as a {@link EncodedReadableHandle file} (or
+ * {@link BinaryReadableHandle binary file} if the request used binary mode), though provides several request specific
+ * methods.
+ *
+ * @cc.module http.Response
+ * @see HTTPAPI#request(IArguments)  On how to make a http request.
  */
-public class HttpResponseHandle implements ILuaObject
+public class HttpResponseHandle implements ObjectSource
 {
-    private final String[] newMethods;
-    private final int methodOffset;
-    private final ILuaObject reader;
+    private final Object reader;
     private final int responseCode;
     private final String responseStatus;
     private final Map<String, String> responseHeaders;
 
-    public HttpResponseHandle( @Nonnull ILuaObject reader, int responseCode, String responseStatus, @Nonnull Map<String, String> responseHeaders )
+    public HttpResponseHandle( @Nonnull HandleGeneric reader, int responseCode, String responseStatus, @Nonnull Map<String, String> responseHeaders )
     {
         this.reader = reader;
         this.responseCode = responseCode;
         this.responseStatus = responseStatus;
         this.responseHeaders = responseHeaders;
-
-        String[] oldMethods = reader.getMethodNames();
-        final int methodOffset = this.methodOffset = oldMethods.length;
-
-        final String[] newMethods = this.newMethods = Arrays.copyOf( oldMethods, oldMethods.length + 2 );
-        newMethods[methodOffset + 0] = "getResponseCode";
-        newMethods[methodOffset + 1] = "getResponseHeaders";
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    /**
+     * Returns the response code and response message returned by the server.
+     *
+     * @return The response code and message.
+     * @cc.treturn number The response code (i.e. 200)
+     * @cc.treturn string The response message (i.e. "OK")
+     */
+    @LuaFunction
+    public final Object[] getResponseCode()
     {
-        return newMethods;
+        return new Object[] { responseCode, responseStatus };
+    }
+
+    /**
+     * Get a table containing the response's headers, in a format similar to that required by {@link HTTPAPI#request}.
+     * If multiple headers are sent with the same name, they will be combined with a comma.
+     *
+     * @return The response's headers.
+     * @cc.usage Make a request to [example.computercraft.cc](https://example.computercraft.cc), and print the
+     * returned headers.
+     * <pre>{@code
+     * local request = http.get("https://example.computercraft.cc")
+     * print(textutils.serialize(request.getResponseHeaders()))
+     * -- => {
+     * --  [ "Content-Type" ] = "text/plain; charset=utf8",
+     * --  [ "content-length" ] = 17,
+     * --  ...
+     * -- }
+     * request.close()
+     * }</pre>
+     */
+    @LuaFunction
+    public final Map<String, String> getResponseHeaders()
+    {
+        return responseHeaders;
     }
 
     @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException, InterruptedException
+    public Iterable<Object> getExtra()
     {
-        if( method < methodOffset ) return reader.callMethod( context, method, args );
-
-        switch( method - methodOffset )
-        {
-            case 0: // getResponseCode
-                return new Object[] { responseCode, responseStatus };
-            case 1: // getResponseHeaders
-                return new Object[] { responseHeaders };
-            default:
-                return null;
-        }
+        return Collections.singletonList( reader );
     }
 }

src/main/java/dan200/computercraft/core/apis/http/websocket/Websocket.java

@@ -12,6 +12,7 @@ import dan200.computercraft.core.apis.http.HTTPRequestException;
 import dan200.computercraft.core.apis.http.NetworkUtils;
 import dan200.computercraft.core.apis.http.Resource;
 import dan200.computercraft.core.apis.http.ResourceGroup;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.shared.util.IoUtil;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
@@ -130,6 +131,7 @@ public class Websocket extends Resource<Websocket>
             boolean ssl = uri.getScheme().equalsIgnoreCase( "wss" );
 
             InetSocketAddress socketAddress = NetworkUtils.getAddress( uri.getHost(), uri.getPort(), ssl );
+            Options options = NetworkUtils.getOptions( uri.getHost(), socketAddress );
             SslContext sslContext = ssl ? NetworkUtils.getSslContext() : null;
 
             // getAddress may have a slight delay, so let's perform another cancellation check.
@@ -151,14 +153,14 @@ public class Websocket extends Resource<Websocket>
 
                         WebSocketClientHandshaker handshaker = WebSocketClientHandshakerFactory.newHandshaker(
                             uri, WebSocketVersion.V13, null, true, headers,
-                            ComputerCraft.httpMaxWebsocketMessage == 0 ? MAX_MESSAGE_SIZE : ComputerCraft.httpMaxWebsocketMessage
+                            options.websocketMessage <= 0 ? MAX_MESSAGE_SIZE : options.websocketMessage
                         );
 
                         p.addLast(
                             new HttpClientCodec(),
                             new HttpObjectAggregator( 8192 ),
                             WebSocketClientCompressionHandler.INSTANCE,
-                            new WebsocketHandler( Websocket.this, handshaker )
+                            new WebsocketHandler( Websocket.this, handshaker, options )
                         );
                     }
                 } )
@@ -178,16 +180,16 @@ public class Websocket extends Resource<Websocket>
         catch( Exception e )
         {
             failure( "Could not connect" );
-            if( ComputerCraft.logPeripheralErrors ) ComputerCraft.log.error( "Error in websocket", e );
+            if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in websocket", e );
         }
     }
 
-    void success( Channel channel )
+    void success( Channel channel, Options options )
     {
         if( isClosed() ) return;
 
-        WebsocketHandle handle = new WebsocketHandle( this, channel );
-        environment().queueEvent( SUCCESS_EVENT, new Object[] { address, handle } );
+        WebsocketHandle handle = new WebsocketHandle( this, options, channel );
+        environment().queueEvent( SUCCESS_EVENT, address, handle );
         websocketHandle = createOwnerReference( handle );
 
         checkClosed();
@@ -195,18 +197,16 @@ public class Websocket extends Resource<Websocket>
 
     void failure( String message )
     {
-        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, new Object[] { address, message } );
+        if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message );
     }
 
     void close( int status, String reason )
     {
         if( tryClose() )
         {
-            environment.queueEvent( CLOSE_EVENT, new Object[] {
-                address,
+            environment.queueEvent( CLOSE_EVENT, address,
                 Strings.isNullOrEmpty( reason ) ? null : reason,
-                status < 0 ? null : status,
-            } );
+                status < 0 ? null : status );
         }
     }
 
@@ -220,7 +220,7 @@ public class Websocket extends Resource<Websocket>
 
         WeakReference<WebsocketHandle> websocketHandleRef = websocketHandle;
         WebsocketHandle websocketHandle = websocketHandleRef == null ? null : websocketHandleRef.get();
-        if( websocketHandle != null ) IoUtil.closeQuietly( websocketHandle );
+        IoUtil.closeQuietly( websocketHandle );
         this.websocketHandle = null;
     }
 

src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandle.java

@@ -6,11 +6,8 @@
 package dan200.computercraft.core.apis.http.websocket;
 
 import com.google.common.base.Objects;
-import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.lua.ArgumentHelper;
-import dan200.computercraft.api.lua.ILuaContext;
-import dan200.computercraft.api.lua.ILuaObject;
-import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.*;
+import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.core.tracking.TrackingField;
 import dan200.computercraft.shared.util.StringUtil;
 import io.netty.buffer.Unpooled;
@@ -19,109 +16,96 @@ import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import java.io.Closeable;
 import java.util.Arrays;
+import java.util.Optional;
 
-import static dan200.computercraft.api.lua.ArgumentHelper.optBoolean;
+import static dan200.computercraft.api.lua.LuaValues.checkFinite;
 import static dan200.computercraft.core.apis.IAPIEnvironment.TIMER_EVENT;
 import static dan200.computercraft.core.apis.http.websocket.Websocket.CLOSE_EVENT;
 import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
 
-public class WebsocketHandle implements ILuaObject, Closeable
+/**
+ * A websocket, which can be used to send an receive messages with a web server.
+ *
+ * @cc.module http.Websocket
+ * @see dan200.computercraft.core.apis.HTTPAPI#websocket On how to open a websocket.
+ */
+public class WebsocketHandle implements Closeable
 {
     private final Websocket websocket;
+    private final Options options;
     private boolean closed = false;
 
     private Channel channel;
 
-    public WebsocketHandle( Websocket websocket, Channel channel )
+    public WebsocketHandle( Websocket websocket, Options options, Channel channel )
     {
         this.websocket = websocket;
+        this.options = options;
         this.channel = channel;
     }
 
-    @Nonnull
-    @Override
-    public String[] getMethodNames()
+    /**
+     * Wait for a message from the server.
+     *
+     * @param timeout The number of seconds to wait if no message is received.
+     * @return The result of receiving.
+     * @throws LuaException If the websocket has been closed.
+     * @cc.treturn [1] string The received message.
+     * @cc.treturn boolean If this was a binary message.
+     * @cc.treturn [2] nil If the websocket was closed while waiting, or if we timed out.
+     */
+    @LuaFunction
+    public final MethodResult receive( Optional<Double> timeout ) throws LuaException
     {
-        return new String[] { "receive", "send", "close" };
+        checkOpen();
+        int timeoutId = timeout.isPresent()
+            ? websocket.environment().startTimer( Math.round( checkFinite( 0, timeout.get() ) / 0.05 ) )
+            : -1;
+
+        return new ReceiveCallback( timeoutId ).pull;
     }
 
-    @Nullable
-    @Override
-    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException
+    /**
+     * Send a websocket message to the connected server.
+     *
+     * @param message The message to send.
+     * @param binary  Whether this message should be treated as a
+     * @throws LuaException If the message is too large.
+     * @throws LuaException If the websocket has been closed.
+     */
+    @LuaFunction
+    public final void send( Object message, Optional<Boolean> binary ) throws LuaException
     {
-        switch( method )
+        checkOpen();
+
+        String text = StringUtil.toString( message );
+        if( options.websocketMessage != 0 && text.length() > options.websocketMessage )
         {
-            case 0: // receive
-            {
-                checkOpen();
-                int timeoutId;
-                if( arguments.length <= 0 || arguments[0] == null )
-                {
-                    // We do this rather odd argument validation to ensure we can tell the difference between a
-                    // negative timeout and an absent one.
-                    timeoutId = -1;
-                }
-                else
-                {
-                    double timeout = ArgumentHelper.getFiniteDouble( arguments, 0 );
-                    timeoutId = websocket.environment().startTimer( Math.round( timeout / 0.05 ) );
-                }
-
-                while( true )
-                {
-                    Object[] event = context.pullEvent( null );
-                    if( event.length >= 3 && Objects.equal( event[0], MESSAGE_EVENT ) && Objects.equal( event[1], websocket.address() ) )
-                    {
-                        return Arrays.copyOfRange( event, 2, event.length );
-                    }
-                    else if( event.length >= 2 && Objects.equal( event[0], CLOSE_EVENT ) && Objects.equal( event[1], websocket.address() ) && closed )
-                    {
-                        // If the socket is closed abort.
-                        return null;
-                    }
-                    else if( event.length >= 2 && timeoutId != -1 && Objects.equal( event[0], TIMER_EVENT )
-                        && event[1] instanceof Number && ((Number) event[1]).intValue() == timeoutId )
-                    {
-                        // If we received a matching timer event then abort.
-                        return null;
-                    }
-                }
-            }
-
-            case 1: // send
-            {
-                checkOpen();
-
-                String text = arguments.length > 0 && arguments[0] != null ? arguments[0].toString() : "";
-                if( ComputerCraft.httpMaxWebsocketMessage != 0 && text.length() > ComputerCraft.httpMaxWebsocketMessage )
-                {
-                    throw new LuaException( "Message is too large" );
-                }
-
-                boolean binary = optBoolean( arguments, 1, false );
-                websocket.environment().addTrackingChange( TrackingField.WEBSOCKET_OUTGOING, text.length() );
-
-                Channel channel = this.channel;
-                if( channel != null )
-                {
-                    channel.writeAndFlush( binary
-                        ? new BinaryWebSocketFrame( Unpooled.wrappedBuffer( StringUtil.encodeString( text ) ) )
-                        : new TextWebSocketFrame( text ) );
-                }
-
-                return null;
-            }
-
-            case 2: // close
-                close();
-                websocket.close();
-                return null;
-            default:
-                return null;
+            throw new LuaException( "Message is too large" );
         }
+
+        websocket.environment().addTrackingChange( TrackingField.WEBSOCKET_OUTGOING, text.length() );
+
+        Channel channel = this.channel;
+        if( channel != null )
+        {
+            channel.writeAndFlush( binary.orElse( false )
+                ? new BinaryWebSocketFrame( Unpooled.wrappedBuffer( LuaValues.encode( text ) ) )
+                : new TextWebSocketFrame( text ) );
+        }
+    }
+
+    /**
+     * Close this websocket. This will terminate the connection, meaning messages can no longer be sent or received
+     * along it.
+     */
+    @LuaFunction( "close" )
+    public final void doClose()
+    {
+        close();
+        websocket.close();
     }
 
     private void checkOpen() throws LuaException
@@ -141,4 +125,38 @@ public class WebsocketHandle implements ILuaObject, Closeable
             this.channel = null;
         }
     }
+
+    private final class ReceiveCallback implements ILuaCallback
+    {
+        final MethodResult pull = MethodResult.pullEvent( null, this );
+        private final int timeoutId;
+
+        ReceiveCallback( int timeoutId )
+        {
+            this.timeoutId = timeoutId;
+        }
+
+        @Nonnull
+        @Override
+        public MethodResult resume( Object[] event )
+        {
+            if( event.length >= 3 && Objects.equal( event[0], MESSAGE_EVENT ) && Objects.equal( event[1], websocket.address() ) )
+            {
+                return MethodResult.of( Arrays.copyOfRange( event, 2, event.length ) );
+            }
+            else if( event.length >= 2 && Objects.equal( event[0], CLOSE_EVENT ) && Objects.equal( event[1], websocket.address() ) && closed )
+            {
+                // If the socket is closed abort.
+                return MethodResult.of();
+            }
+            else if( event.length >= 2 && timeoutId != -1 && Objects.equal( event[0], TIMER_EVENT )
+                && event[1] instanceof Number && ((Number) event[1]).intValue() == timeoutId )
+            {
+                // If we received a matching timer event then abort.
+                return MethodResult.of();
+            }
+
+            return pull;
+        }
+    }
 }