mirror of
https://github.com/janet-lang/janet
synced 2024-11-28 02:59:54 +00:00
Update README.md
This commit is contained in:
parent
5f56bf836c
commit
7d48b75f81
111
README.md
111
README.md
@ -6,10 +6,8 @@
|
||||
|
||||
<img src="https://raw.githubusercontent.com/janet-lang/janet/master/assets/janet-w200.png" alt="Janet logo" width=200 align="left">
|
||||
|
||||
**Janet** is a functional and imperative programming language and bytecode interpreter. It is a
|
||||
Lisp-like language, but lists are replaced
|
||||
by other data structures (arrays, tables (hash table), struct (immutable hash table), tuples).
|
||||
The language also supports bridging to native code written in C, meta-programming with macros, and bytecode assembly.
|
||||
**Janet** is a dynamic language and bytecode interpreter for system scripting, expressive automation, and
|
||||
extending programs written in C or C++ with user scripting capabilities.
|
||||
|
||||
There is a REPL for trying out the language, as well as the ability
|
||||
to run script files. This client program is separate from the core runtime, so
|
||||
@ -21,14 +19,104 @@ If you'd like to financially support the ongoing development of Janet, consider
|
||||
|
||||
<br>
|
||||
|
||||
## Examples
|
||||
|
||||
See the examples directory for all provided example programs.
|
||||
|
||||
### Game of Life
|
||||
|
||||
```janet
|
||||
# John Conway's Game of Life
|
||||
|
||||
(def- window
|
||||
(seq [x :range [-1 2]
|
||||
y :range [-1 2]
|
||||
:when (not (and (zero? x) (zero? y)))]
|
||||
[x y]))
|
||||
|
||||
(defn- neighbors
|
||||
[[x y]]
|
||||
(map (fn [[x1 y1]] [(+ x x1) (+ y y1)]) window))
|
||||
|
||||
(defn tick
|
||||
"Get the next state in the Game Of Life."
|
||||
[state]
|
||||
(def cell-set (frequencies state))
|
||||
(def neighbor-set (frequencies (mapcat neighbors state)))
|
||||
(seq [coord :keys neighbor-set
|
||||
:let [count (get neighbor-set coord)]
|
||||
:when (or (= count 3) (and (get cell-set coord) (= count 2)))]
|
||||
coord))
|
||||
|
||||
(defn draw
|
||||
"Draw cells in the game of life from (x1, y1) to (x2, y2)"
|
||||
[state x1 y1 x2 y2]
|
||||
(def cellset @{})
|
||||
(each cell state (put cellset cell true))
|
||||
(loop [x :range [x1 (+ 1 x2)]
|
||||
:after (print)
|
||||
y :range [y1 (+ 1 y2)]]
|
||||
(file/write stdout (if (get cellset [x y]) "X " ". ")))
|
||||
(print))
|
||||
|
||||
# Print the first 20 generations of a glider
|
||||
(var *state* '[(0 0) (-1 0) (1 0) (1 1) (0 2)])
|
||||
(for i 0 20
|
||||
(print "generation " i)
|
||||
(draw *state* -7 -7 7 7)
|
||||
(set *state* (tick *state*)))
|
||||
```
|
||||
|
||||
### TCP Echo Server
|
||||
|
||||
```janet
|
||||
# A simple TCP echo server using the built-in socket networking and event loop.
|
||||
|
||||
(defn handler
|
||||
"Simple handler for connections."
|
||||
[stream]
|
||||
(defer (:close stream)
|
||||
(def id (gensym))
|
||||
(def b @"")
|
||||
(print "Connection " id "!")
|
||||
(while (:read stream 1024 b)
|
||||
(printf " %v -> %v" id b)
|
||||
(:write stream b)
|
||||
(buffer/clear b))
|
||||
(printf "Done %v!" id)
|
||||
(ev/sleep 0.5)))
|
||||
|
||||
(net/server "127.0.0.1" "8000" handler)
|
||||
```
|
||||
|
||||
### Windows FFI Hello, World!
|
||||
|
||||
```janet
|
||||
# Use the FFI to popup a Windows message box - no C required
|
||||
|
||||
(ffi/context "user32.dll")
|
||||
|
||||
(ffi/defbind MessageBoxA :int
|
||||
[w :ptr text :string cap :string typ :int])
|
||||
|
||||
(MessageBoxA nil "Hello, World!" "Test" 0)
|
||||
```
|
||||
|
||||
## Use Cases
|
||||
|
||||
Janet makes a good system scripting language, or a language to embed in other programs.
|
||||
It's like Lua and Guile in that regard. It has more built-in functionality and a richer core language than
|
||||
Lua, but smaller than GNU Guile or Python.
|
||||
Lua, but smaller than GNU Guile or Python. However, it is much easier to embed and port than these languages.
|
||||
|
||||
## Features
|
||||
|
||||
* 600+ functions and macros in the core library
|
||||
* Build in socket networking, threading, subprocesses, and more.
|
||||
* Parsing Expression Grammars (PEG) engine as a more robust Regex alternative
|
||||
* Macros
|
||||
* Per-thread event loop for efficient IO (epoll/IOCP/kqueue)
|
||||
* Built-in C FFI lets you load existing binaries and run them.
|
||||
* Erlang-style supervision trees that integrate with the event loop
|
||||
* Configurable at build time - turn features on or off for a smaller or more featureful build
|
||||
* Minimal setup - one binary and you are good to go!
|
||||
* First-class closures
|
||||
@ -38,19 +126,12 @@ Lua, but smaller than GNU Guile or Python.
|
||||
* Mutable and immutable arrays (array/tuple)
|
||||
* Mutable and immutable hashtables (table/struct)
|
||||
* Mutable and immutable strings (buffer/string)
|
||||
* Macros
|
||||
* Multithreading
|
||||
* Per-thread event loop for efficient evented IO
|
||||
* Bytecode interpreter with an assembly interface, as well as bytecode verification
|
||||
* Tail-call optimization
|
||||
* Direct interop with C via abstract types and C functions
|
||||
* Interface with C via abstract types and C functions
|
||||
* Dynamically load C libraries
|
||||
* Functional and imperative standard library
|
||||
* Lexical scoping
|
||||
* Imperative programming as well as functional
|
||||
* REPL
|
||||
* Parsing Expression Grammars built into the core library
|
||||
* 400+ functions and macros in the core library
|
||||
* Embedding Janet in other programs
|
||||
* Interactive environment with detailed stack traces
|
||||
|
||||
@ -240,10 +321,6 @@ there is no need for dynamic modules, add the define
|
||||
|
||||
See the [Embedding Section](https://janet-lang.org/capi/embedding.html) on the website for more information.
|
||||
|
||||
## Examples
|
||||
|
||||
See the examples directory for some example Janet code.
|
||||
|
||||
## Discussion
|
||||
|
||||
Feel free to ask questions and join the discussion on the [Janet Gitter channel](https://gitter.im/janet-language/community).
|
||||
|
Loading…
Reference in New Issue
Block a user