Merge branch 'master' into net

2024-06-21 04:39:55 +00:00 · 2020-04-17 15:08:26 -05:00 · 2020-04-17 15:08:26 -05:00 · 596111c988
commit 596111c988
parent 65403ec9fe e202d30835
51 changed files with 2088 additions and 574 deletions
--- a/.gitignore
+++ b/.gitignore
@ -13,6 +13,9 @@ janet
 janet-*.tar.gz
 dist

+# jpm lockfile
+lockfile.janet
+
 # Kakoune (fzf via fd)
 .fdignore

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -1,9 +1,40 @@
 # Changelog
 All notable changes to this project will be documented in this file.

-## Unreleased
+## Unreleased - ???
+- Fix bug in `getline`.
+- Add `sh-rule` and `sh-phony` to jpm's dialect of Janet.
+- Change C api's `janet_formatb` -> `janet_formatbv`.
+- Add C `janet_formatb` to C api.
+- Add `edefer` macro to core.
+- A struct/table literal/constructor with duplicate keys will use the last value given.
+  Previously, this was inconsistent between tables and structs, literals and constructor functions.
+- Add debugger to core. The debugger functions are only available
+  in a debug repl, and are prefixed by a `.`.
+- Add `sort-by` and `sorted-by` to core.
+- Support UTF-8 escapes in strings via `\uXXXX` or `\UXXXXXX`.
+- Add `math/erf`
+- Add `math/erfc`
+- Add `math/log1p`
+- Add `math/next`
+- Add os/umask
+- Add os/perm-int
+- Add os/perm-string
+- Add :octal-permissions option for os/stat.
+- Add `jpm repl` subcommand, as well as `post-deps` macro in project.janet files.
+
+## 1.8.1 - 2020-03-31
+- Fix bugs for big endian systems
+- Fix 1.8.0 regression on BSDs
+
+## 1.8.0 - 2020-03-29
+- Add `reduce2`, `accumulate`, and `accumulate2`.
+- Add lockfiles to `jpm` via `jpm make-lockfile` and `jpm load-lockfile`.
+- Add `os/realpath` (Not supported on windows).
+- Add `os/chmod`.
+- Add `chr` macro.
 - Allow `_` in the `match` macro to match anything without creating a binding
-  or doing unification.
+  or doing unification. Also change behavior of matching nil.
 - Add `:range-to` and `:down-to` verbs in the `loop` macro.
 - Fix `and` and `or` macros returning nil instead of false in some cases.
 - Allow matching successfully against nil values in the `match` macro.
@ -17,7 +48,8 @@ All notable changes to this project will be documented in this file.
 - Correct arity for `marshal`
 - Add `flush` and `eflush`
 - Add `prompt` and `return` on top of signal for user friendly delimited continuations.
- Fix possible segfault with malformed pegs.
+- Fix bug in buffer/blit when using the offset-src argument.
+- Fix segfault with malformed pegs.

 ## 1.7.0 - 2020-02-01
 - Remove `file/fileno` and `file/fdopen`.
--- a/10
+++ b/10
@ -36,6 +36,7 @@ JANET_PATH?=$(LIBDIR)/janet
 MANPATH?=$(PREFIX)/share/man/man1/
 PKG_CONFIG_PATH?=$(LIBDIR)/pkgconfig
 DEBUGGER=gdb
+SONAME_SETTER=-Wl,-soname,

 CFLAGS:=$(CFLAGS) -std=c99 -Wall -Wextra -Isrc/include -Isrc/conf -fPIC -O2 -fvisibility=hidden
 LDFLAGS:=$(LDFLAGS) -rdynamic
@ -47,6 +48,7 @@ LDCONFIG:=ldconfig "$(LIBDIR)"
 UNAME:=$(shell uname -s)
 ifeq ($(UNAME), Darwin)
 	CLIBS:=$(CLIBS) -ldl
+	SONAME_SETTER:=-Wl,-install_name,
 	LDCONFIG:=true
 else ifeq ($(UNAME), Linux)
 	CLIBS:=$(CLIBS) -lrt -ldl
@ -147,6 +149,8 @@ build/janet.c: build/janet_boot src/boot/boot.janet
 ##### Amalgamation #####
 ########################

+SONAME=libjanet.so.1.9
+
 build/shell.c: src/mainclient/shell.c
 	cp $< $@

@ -166,7 +170,7 @@ $(JANET_TARGET): build/janet.o build/shell.o
 	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $^ $(CLIBS)

 $(JANET_LIBRARY): build/janet.o build/shell.o
-	$(CC) $(LDFLAGS) $(CFLAGS) -shared -o $@ $^ $(CLIBS)
+	$(CC) $(LDFLAGS) $(CFLAGS) $(SONAME_SETTER)$(SONAME) -shared -o $@ $^ $(CLIBS)

 $(JANET_STATIC_LIBRARY): build/janet.o build/shell.o
 	$(AR) rcs $@ $^
@ -229,8 +233,6 @@ build/doc.html: $(JANET_TARGET) tools/gendoc.janet
 ##### Installation #####
 ########################

-SONAME=libjanet.so.1
-
 .INTERMEDIATE: build/janet.pc
 build/janet.pc: $(JANET_TARGET)
 	echo 'prefix=$(PREFIX)' > $@
@ -243,7 +245,7 @@ build/janet.pc: $(JANET_TARGET)
 	echo "Description: Library for the Janet programming language." >> $@
 	$(JANET_TARGET) -e '(print "Version: " janet/version)' >> $@
 	echo 'Cflags: -I$${includedir}' >> $@
-	echo 'Libs: -L$${libdir} -ljanet $(LDFLAGS)' >> $@
+	echo 'Libs: -L$${libdir} -ljanet' >> $@
 	echo 'Libs.private: $(CLIBS)' >> $@

 install: $(JANET_TARGET) build/janet.pc
--- a/README.md
+++ b/README.md
@ -2,26 +2,28 @@
 &nbsp;
 [![Appveyor Status](https://ci.appveyor.com/api/projects/status/bjraxrxexmt3sxyv/branch/master?svg=true)](https://ci.appveyor.com/project/bakpakin/janet/branch/master)
 [![Build Status](https://travis-ci.org/janet-lang/janet.svg?branch=master)](https://travis-ci.org/janet-lang/janet)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/.freebsd.yaml.svg)](https://builds.sr.ht/~bakpakin/janet/.freebsd.yaml?)
-[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/.openbsd.yaml.svg)](https://builds.sr.ht/~bakpakin/janet/.openbsd.yaml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/freebsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/freebsd.yml?)
+[![builds.sr.ht status](https://builds.sr.ht/~bakpakin/janet/openbsd.yml.svg)](https://builds.sr.ht/~bakpakin/janet/openbsd.yml?)

 <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
 modern lisp, but lists are replaced
-by other data structures with better utility and performance (arrays, tables, structs, tuples).
+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.

 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
-janet can be embedded into other programs. Try janet in your browser at
+Janet can be embedded into other programs. Try Janet in your browser at
 [https://janet-lang.org](https://janet-lang.org).

 <br>

 ## Use Cases

-Janet makes a good system scripting language, or a language to embed in other programs, like Lua or Guile.
+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.

 ## Features

@ -43,7 +45,7 @@ Janet makes a good system scripting language, or a language to embed in other pr
 * Imperative programming as well as functional
 * REPL
 * Parsing Expression Grammars built in to the core library
-* 300+ functions and macros in the core library
+* 400+ functions and macros in the core library
 * Embedding Janet in other programs
 * Interactive environment with detailed stack traces

--- a/appveyor.yml
+++ b/appveyor.yml
@ -30,7 +30,7 @@ install:
    - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" %platform%
    - build_win test-install
    - set janet_outname=%appveyor_repo_tag_name%
-    - if "%janet_outname%"=="" set janet_outname=v1.7.1
+    - if "%janet_outname%"=="" set /P janet_outname=<build\version.txt
 build: off

 artifacts:
@ -49,8 +49,7 @@ artifacts:
    - name: "janet-$(janet_outname)-windows-%platform%"
      path: dist
      type: Zip
-    - path: "janet-$(janet_outname)-windows-installer.exe"
-      name: "janet-$(janet_outname)-windows-%platform%-installer.exe"
+    - path: "janet-$(janet_outname)-windows-%platform%-installer.exe"
      type: File

 deploy:
--- a/auxbin/jpm
+++ b/auxbin/jpm
@ -34,7 +34,7 @@
 (defmacro rule
  "Add a rule to the rule graph."
  [target deps & body]
-  ~(,rule-impl ,target ,deps (fn [] nil ,;body)))
+  ~(,rule-impl ,target ,deps (fn [] ,;body)))

 (defmacro phony
  "Add a phony rule to the rule graph. A phony rule will run every time
@ -43,6 +43,16 @@
  [target deps & body]
  ~(,rule-impl ,target ,deps (fn [] nil ,;body) true))

+(defmacro sh-rule
+  "Add a rule that invokes a shell command, and fails if the command returns non-zero."
+  [target deps & body]
+  ~(,rule-impl ,target ,deps (fn [] (,assert (,zero? (,os/shell (,string ,;body)))))))
+
+(defmacro sh-phony
+  "Add a phony rule that invokes a shell command, and fails if the command returns non-zero."
+  [target deps & body]
+  ~(,rule-impl ,target ,deps (fn [] (,assert (,zero? (,os/shell (,string ,;body))))) true))
+
 (defn add-dep
  "Add a dependency to an existing rule. Useful for extending phony
  rules or extending the dependency graph of existing rules."
@ -177,24 +187,46 @@
  [into x]
  (when x
    (proto-flatten into (table/getproto x))
-    (loop [k :keys x]
-      (put into k (x k))))
+    (merge-into into x))
  into)

-(defn import-rules
-  "Import another file that defines more rules. This ruleset
-  is merged into the current ruleset."
-  [path]
+(defn make-jpm-env
+  "Build an environment table with jpm functions preloaded."
+  [&opt no-deps]
  (def env (make-env))
-  (unless (os/stat path :mode)
-    (error (string "cannot open " path)))
+  (put env :jpm-no-deps no-deps)
  (loop [k :keys _env :when (symbol? k)]
     (unless ((_env k) :private) (put env k (_env k))))
+  env)
+
+(defn require-jpm
+  "Require a jpm file project file. This is different from a normal require
+  in that code is loaded in the jpm environment."
+  [path &opt no-deps]
+  (unless (os/stat path :mode)
+    (error (string "cannot open " path)))
+  (def env (make-jpm-env no-deps))
  (def currenv (proto-flatten @{} (fiber/getenv (fiber/current))))
  (loop [k :keys currenv :when (keyword? k)]
    (put env k (currenv k)))
  (dofile path :env env :exit true)
-  (when-let [rules (env :rules)] (merge-into (getrules) rules)))
+  env)
+
+(defn import-rules
+  "Import another file that defines more rules. This ruleset
+  is merged into the current ruleset."
+  [path &opt no-deps]
+  (def env (require-jpm path no-deps))
+  (when-let [rules (env :rules)] (merge-into (getrules) rules))
+  env)
+
+(defmacro post-deps
+  "Run code at the top level if jpm dependencies are installed. Build
+  code that imports dependencies should be wrapped with this macro, as project.janet
+  needs to be able to run successfully even without dependencies installed."
+  [& body]
+  (unless (dyn :jpm-no-deps)
+    ~',(reduce |(eval $1) nil body)))

 #
 # OS and shell helpers
@ -251,11 +283,7 @@
  If we can't create it, give a friendly error. Return true if created, false if
  existing. Throw an error if we can't create it."
  [dir]
-  (if (os/mkdir dir)
-    true
-    (if (os/stat dir :mode)
-      false
-      (error (string "Could not create " dir " - this could be a permission issue.")))))
+  (os/mkdir dir))

 #
 # C Compilation
@ -557,6 +585,15 @@ int main(int argc, const char **argv) {
 # Public utilities
 #

+(defn parse
+  "Read a string of Janet source and parse out the first expression."
+  [src]
+  (let [p (parser/new)]
+    (:consume p src)
+    (if (= :error (:status p))
+      (error (string "Could not parse: " (parser/error p))))
+    (:produce p)))
+
 (defn find-manifest-dir
  "Get the path to the directory containing manifests for installed
  packages."
@ -566,7 +603,7 @@ int main(int argc, const char **argv) {
 (defn find-manifest
  "Get the full path of a manifest file given a package name."
  [name]
-  (string (find-manifest-dir) sep name ".txt"))
+  (string (find-manifest-dir) sep name ".jdn"))

 (defn find-cache
  "Return the path to the global cache."
@ -578,17 +615,14 @@ int main(int argc, const char **argv) {
  "Uninstall bundle named name"
  [name]
  (def manifest (find-manifest name))
-  (def f (file/open manifest :r))
-  (unless f (print manifest " does not exist") (break))
-  (loop [line :iterate (:read f :line)]
-    (def path ((string/split "\n" line) 0))
-    (def path ((string/split "\r" path) 0))
-    (print "removing " path)
-    (rm path))
-  (:close f)
-  (print "removing " manifest)
-  (rm manifest)
-  (print "Uninstalled."))
+  (when-with [f (file/open manifest)]
+    (def man (parse (:read f :all)))
+    (each path (get man :paths [])
+      (print "removing " path)
+      (rm path))
+    (print "removing " manifest)
+    (rm manifest)
+    (print "Uninstalled.")))

 (defn- rimraf
  "Hard delete directory tree"
@ -610,7 +644,7 @@ int main(int argc, const char **argv) {
 (defn install-git
  "Install a bundle from git. If the bundle is already installed, the bundle
   is reinistalled (but not rebuilt if artifacts are cached)."
-  [repotab &opt recurse]
+  [repotab &opt recurse no-deps]
  (def repo (if (string? repotab) repotab (repotab :repo)))
  (def tag (unless (string? repotab) (repotab :tag)))
  # prevent infinite recursion (very unlikely, but consider
@ -655,7 +689,7 @@ int main(int argc, const char **argv) {
        (os/execute ["git" "reset" "--hard" tag] :p))
      (os/execute ["git" "submodule" "update" "--init" "--recursive"] :p)
      (import-rules "./project.janet")
-      (do-rule "install-deps")
+      (unless no-deps (do-rule "install-deps"))
      (do-rule "build")
      (do-rule "install"))
    ([err] (print "Error building git repository dependency: " err)))
@ -672,6 +706,49 @@ int main(int argc, const char **argv) {
            (mkdir destdir)
            (copy src destdir)))

+(defn- pslurp
+  "Like slurp, but with file/popen instead file/open. Also trims output"
+  [cmd]
+  (string/trim (with [f (file/popen cmd)] (:read f :all))))
+
+(defn- make-lockfile
+  [&opt filename]
+  (default filename "lockfile.janet")
+  (def cwd (os/cwd))
+  (def packages @[])
+  # Read installed modules from manifests
+  (def mdir (find-manifest-dir))
+  (each man (os/dir mdir)
+    (def package (parse (slurp (string mdir sep man))))
+    (if (and (dictionary? package) (package :repo) (package :sha))
+      (array/push packages package)
+      (print "Cannot add local or malformed package " mdir sep man " to lockfile, skipping...")))
+  # Put in correct order, such that a package is preceded by all of its dependencies
+  (def ordered-packages @[])
+  (def resolved @{})
+  (while (< (length ordered-packages) (length packages))
+    (var made-progress false)
+    (each p packages
+      (def {:repo r :sha s :dependencies d} p)
+      (def dep-urls (map |(if (string? $) $ ($ :repo)) d))
+      (unless (resolved r)
+        (when (all resolved dep-urls)
+          (array/push ordered-packages {:repo r :sha s})
+          (set made-progress true)
+          (put resolved r true))))
+    (unless made-progress
+      (error (string/format "could not resolve package order for: %j"
+                            (filter (complement resolved) (map |($ :repo) packages))))))
+  # Write to file
+  (with [f (file/open filename :w)] (with-dyns [:out f] (printf "%j" ordered-packages))))
+
+(defn- load-lockfile
+  [&opt filename]
+  (default filename "lockfile.janet")
+  (def lockarray (parse (slurp filename)))
+  (each {:repo url :sha sha} lockarray
+    (install-git {:repo url :tag sha} nil true)))
+
 #
 # Declaring Artifacts - used in project.janet, targets specifically
 # tailored for janet.
@ -756,13 +833,15 @@ int main(int argc, const char **argv) {
  is marshalled into bytecode which is then embedded in a final executable for distribution.\n\n
  This executable can be installed as well to the --binpath given."
  [&keys {:install install :name name :entry entry :headers headers
-          :cflags cflags :lflags lflags}]
+          :cflags cflags :lflags lflags :deps deps}]
  (def name (if is-win (string name ".exe") name))
  (def dest (string "build" sep name))
  (create-executable @{:cflags cflags :lflags lflags} entry dest)
  (add-dep "build" dest)
  (when headers
    (each h headers (add-dep dest h)))
+  (when deps
+    (each d deps (add-dep dest d)))
  (when install
    (install-rule dest (dyn :binpath JANET_BINPATH))))

@ -817,7 +896,15 @@ int main(int argc, const char **argv) {
  (phony "manifest" []
         (print "generating " manifest "...")
         (mkdir manifests)
-         (spit manifest (string (string/join installed-files "\n") "\n")))
+         (def sha (pslurp "git rev-parse HEAD"))
+         (def url (pslurp "git remote get-url origin"))
+         (def man
+           {:sha (if-not (empty? sha) sha)
+            :repo (if-not (empty? url) url)
+            :dependencies (array/slice (get meta :dependencies []))
+            :paths installed-files})
+         (spit manifest (string/format "%j\n" man)))
+
  (phony "install" ["uninstall" "build" "manifest"]
         (when (dyn :test)
           (do-rule "test"))
@ -861,8 +948,8 @@ int main(int argc, const char **argv) {
    '(* "--" '(some (if-not "=" 1)) (+ (* "=" '(any 1)) -1))))

 (defn- local-rule
-  [rule]
-  (import-rules "./project.janet")
+  [rule &opt no-deps]
+  (import-rules "./project.janet" no-deps)
  (do-rule rule))

 (defn- help
@ -891,6 +978,14 @@ Subcommands are:
  rules : list rules available with run.
  update-pkgs : Update the current package listing from the remote git repository selected.
  quickbin entry executable : Create an executable from a janet script with a main function.
+  make-lockfile (lockfile) : Create a lockfile based on repositories in the cache. The
+            lockfile will record the exact versions of dependencies used to ensure a reproducible
+            build. Lockfiles are best used with applications, not libraries. The default lockfile
+            name is lockfile.janet.
+  load-lockfile (lockfile) : Install modules from a lockfile in a reproducible way. The
+                             default lockfile name is lockfile.janet.
+  repl : Run a repl in the context of the current project.janet file. This lets you run rules and
+         otherwise debug the current project.janet file.

 Keys are:
  --modpath : The directory to install modules to. Defaults to $JANET_MODPATH, $JANET_PATH, or (dyn :syspath)
@ -904,15 +999,16 @@ Keys are:
  --pkglist : URL of git repository for package listing. Defaults to $JANET_PKGLIST or https://github.com/janet-lang/pkgs.git

 Flags are:
+  --nocolor : Disable color in the jpm repl.
  --verbose : Print shell commands as they are executed.
  --test : If passed to jpm install, runs tests before installing. Will run tests recursively on dependencies.
    `))

-(defn- show-help
+(defn show-help
  []
  (print help))

-(defn- show-paths
+(defn show-paths
  []
  (print "binpath:    " (dyn :binpath JANET_BINPATH))
  (print "modpath:    " (dyn :modpath JANET_MODPATH))
@ -920,21 +1016,21 @@ Flags are:
  (print "headerpath: " (dyn :headerpath JANET_HEADERPATH))
  (print "syspath:    " (dyn :syspath)))

-(defn- build
+(defn build
  []
  (local-rule "build"))

-(defn- clean
+(defn clean
  []
  (local-rule "clean"))

-(defn- install
+(defn install
  [&opt repo]
  (if repo
    (install-git repo)
    (local-rule "install")))

-(defn- test
+(defn test
  []
  (local-rule "test"))

@ -944,25 +1040,46 @@ Flags are:
    (uninstall what)
    (local-rule "uninstall")))

-(defn- deps
+(defn deps
  []
-  (local-rule "install-deps"))
+  (local-rule "install-deps" true))

-(defn- list-rules
-  []
-  (import-rules "./project.janet")
+(defn list-rules
+  [&opt ctx]
+  (import-rules "./project.janet" true)
  (def ks (sort (seq [k :keys (dyn :rules)] k)))
  (each k ks (print k)))

-(defn- update-pkgs
+(defn update-pkgs
  []
  (install-git (dyn :pkglist default-pkglist)))

-(defn- quickbin
+(defn quickbin
  [input output]
  (create-executable @{} input output)
  (do-rule output))

+(defn jpm-repl
+  []
+  (def env
+    (try
+      (require-jpm "./project.janet")
+    ([err f]
+     (if (= "cannot open ./project.janet" err)
+       (put (make-jpm-env) :project {})
+       (propagate err f)))))
+  (setdyn :pretty-format (if-not (dyn :nocolor) "%.20Q" "%.20q"))
+  (setdyn :err-color (if-not (dyn :nocolor) true))
+  (def p (env :project))
+  (def name (p :name))
+  (if name (print "Project:     " name))
+  (if-let [r (p :repo)] (print "Repository:  " r))
+  (if-let [a (p :author)] (print "Author:      " a))
+  (defn getchunk [buf p]
+    (def [line] (parser/where p))
+    (getline (string "jpm[" (or name "repl") "]:" line ":" (parser/state p :delimiters) "> ") buf env))
+  (repl getchunk nil env))
+
 (def- subcommands
  {"build" build
   "clean" clean
@ -971,12 +1088,15 @@ Flags are:
   "test" test
   "help" help
   "deps" deps
+   "repl" jpm-repl
   "show-paths" show-paths
   "clear-cache" clear-cache
   "run" local-rule
   "rules" list-rules
   "update-pkgs" update-pkgs
   "uninstall" uninstall-cmd
+   "make-lockfile" make-lockfile
+   "load-lockfile" load-lockfile
   "quickbin" quickbin})

 (def- args (tuple/slice (dyn :args) 1))
--- a/build_win.bat
+++ b/build_win.bat
@ -131,7 +131,7 @@ exit /b 0
@rem Run the installer. (Installs to the local user with default settings)
 :INSTALL
@echo Running Installer...
-FOR %%a in (janet-*-windows-installer.exe) DO (
+FOR %%a in (janet-*-windows-*-installer.exe) DO (
    %%a /S /CurrentUser
 )
 exit /b 0
--- a/examples/debugger.janet
+++ b/examples/debugger.janet
@ -1,20 +1,18 @@
 ###
 ### A useful debugger library for Janet. Should be used
-### inside a debug repl.
+### inside a debug repl. This has been moved into the core.
 ###

 (defn .fiber
  "Get the current fiber being debugged."
  []
-  (if-let [entry (dyn '_fiber)]
-    (entry :value)
-    (dyn :fiber)))
+  (dyn :fiber))

 (defn .stack
  "Print the current fiber stack"
  []
  (print)
-  (debug/stacktrace (.fiber) "")
+  (with-dyns [:err-color false] (debug/stacktrace (.fiber) ""))
  (print))

 (defn .frame
--- a/janet-installer.nsi
+++ b/janet-installer.nsi
@ -1,3 +1,6 @@
+# This file is invoked by build_win.bat
+# Relevant configuration variables are set there.
+
 Unicode True

 !echo "Program Files: ${PROGRAMFILES}"
@ -20,6 +23,9 @@ VIFileVersion "${PRODUCT_VERSION}"

 !if ${SIXTYFOUR} == "true"
    !define MULTIUSER_USE_PROGRAMFILES64
+    !define PLATNAME "x64"
+!else
+    !define PLATNAME "x86"
 !endif

 # Includes
@ -36,12 +42,12 @@ Name "Janet"
 !define DOLLAR "$"
 !ifdef CHECK_${DOLLAR}%APPVEYOR_REPO_TAG_NAME%
    # We are not in the appveyor environment, use version name
-    !define OUTNAME_PART v${VERSION}
+    !define OUTNAME_PART ${VERSION}
 !else
    # We are in appveyor, use git tag name for installer
    !define OUTNAME_PART ${OUTNAME}
 !endif
-OutFile "janet-${OUTNAME_PART}-windows-installer.exe"
+OutFile "janet-${OUTNAME_PART}-windows-${PLATNAME}-installer.exe"

 # Some Configuration
 !define APPNAME "Janet"
--- a/janet.1
+++ b/janet.1
@ -96,6 +96,10 @@ Delete everything before the cursor on the input line.
 .BR Ctrl\-W
 Delete one word before the cursor.

+.TP 16
+.BR Ctrl\-G
+Show documentation for the current symbol under the cursor.
+
 .TP 16
 .BR Alt\-B/Alt\-F
 Move cursor backwards and forwards one word.
@ -148,6 +152,12 @@ Read raw input from stdin and forgo prompt history and other readline-like featu
 Execute a string of Janet source. Source code is executed in the order it is encountered, so earlier
 arguments are executed before later ones.

+.TP
+.BR \-d
+Enable debug mode. On all terminating signals as well the debug signal, this will
+cause the debugger to come up in the REPL. Same as calling (setdyn :debug true) in a
+default repl.
+
 .TP
 .BR \-n
 Disable ANSI colors in the repl. Has no effect if no repl is run.
--- a/jpm.1
+++ b/jpm.1
@ -24,6 +24,10 @@ More interesting are the local commands. For more information on jpm usage, see

 .SH FLAGS

+.TP
+.BR \-\-nocolor
+Disable color in the jpm repl.
+
 .TP
 .BR \-\-verbose
 Print detailed messages of what jpm is doing, including compilation commands and other shell commands.
@ -154,6 +158,11 @@ The main function is the entry point of the program and will receive command lin
 as function arguments. The entry file can import other modules, including native C modules, and
 jpm will attempt to include the dependencies into the generated executable.

+.TP
+.BR repl
+Load the current project.janet file and start a repl in it's environment. This lets a user better
+debug the project file, as well as run rules manually.
+
 .SH ENVIRONMENT

 .B JANET_PATH
--- a/meson.build
+++ b/meson.build
@ -20,7 +20,7 @@

 project('janet', 'c',
  default_options : ['c_std=c99', 'b_lundef=false', 'default_library=both'],
-  version : '1.7.1-dev')
+  version : '1.9.0-dev')

 # Global settings
 janet_path = join_paths(get_option('prefix'), get_option('libdir'), 'janet')
@ -162,13 +162,15 @@ janetc = custom_target('janetc',
  output : 'janet.c',
  capture : true,
  command : [
-    janet_boot, '@CURRENT_SOURCE_DIR@',
+    janet_boot, meson.current_source_dir(),
    'JANET_PATH', janet_path, 'JANET_HEADERPATH', header_path
  ])

 libjanet = library('janet', janetc,
  include_directories : incdir,
  dependencies : [m_dep, dl_dep, thread_dep],
+  version: meson.project_version(),
+  soversion: version_parts[0] + '.' + version_parts[1],
  install : true)

 # Extra c flags - adding -fvisibility=hidden matches the Makefile and
--- a/src/boot/boot.janet
+++ b/src/boot/boot.janet
@ -32,7 +32,7 @@
    (def buf (buffer "(" name))
    (while (< index arglen)
      (buffer/push-string buf " ")
-      (buffer/format buf "%p" (in args index))
+      (buffer/format buf "%j" (in args index))
      (set index (+ index 1)))
    (array/push modifiers (string buf ")\n\n" docstr))
    # Build return value
@ -79,8 +79,8 @@

 # Basic predicates
 (defn nan? "Check if x is NaN" [x] (not= x x))
-(defn even? "Check if x is even." [x] (= 0 (% x 2)))
-(defn odd? "Check if x is odd." [x] (not= 0 (% x 2)))
+(defn even? "Check if x is even." [x] (= 0 (mod x 2)))
+(defn odd? "Check if x is odd." [x] (= 1 (mod x 2)))
 (defn zero? "Check if x is zero." [x] (= x 0))
 (defn pos? "Check if x is greater than 0." [x] (> x 0))
 (defn neg? "Check if x is less than 0." [x] (< x 0))
@ -301,7 +301,19 @@
       ,form
       (if (= (,fiber/status ,f) :dead)
         ,r
-         (propagate ,r ,f)))))
+         (,propagate ,r ,f)))))
+
+(defmacro edefer
+  "Run form after body in the case that body terminates abnormally (an error or user signal 0-4).
+  Otherwise, return last form in body."
+  [form & body]
+  (with-syms [f r]
+    ~(do
+       (def ,f (,fiber/new (fn [] ,;body) :ti))
+       (def ,r (,resume ,f))
+       (if (= (,fiber/status ,f) :dead)
+         ,r
+         (do ,form (,propagate ,r ,f))))))

 (defmacro prompt
  "Set up a checkpoint that can be returned to. Tag should be a value
@ -314,7 +326,14 @@
       (def [,target ,payload] ,res)
       (if (,= ,tag ,target)
         ,payload
-         (propagate ,res ,fib)))))
+         (,propagate ,res ,fib)))))
+
+(defmacro chr
+  "Convert a string of length 1 to its byte (ascii) value at compile time."
+  [c]
+  (unless (and (string? c) (= (length c) 1))
+    (error (string/format "expected string of length 1, got %v" c)))
+  (c 0))

 (defmacro label
  "Set a label point that is lexically scoped. Name should be a symbol
@ -460,7 +479,7 @@
  (for-template i start stop 1 < + body))

 (defmacro eachk
-  "loop over each key in ds. returns nil."
+  "Loop over each key in ds. Returns nil."
  [x ds & body]
  (keys-template x ds false body))

@ -482,7 +501,7 @@
  that define something to loop over. They are formatted like:\n\n
  \tbinding :verb object/expression\n\n
  Where binding is a binding as passed to def, :verb is one of a set of keywords,
-  and object is any janet expression. The available verbs are:\n\n
+  and object is any expression. The available verbs are:\n\n
  \t:iterate - repeatedly evaluate and bind to the expression while it is truthy.\n
  \t:range - loop over a range. The object should be two element tuple with a start
  and end value, and an optional positive step. The range is half open, [start, end).\n
@ -641,7 +660,7 @@
 (defn last
  "Get the last element from an indexed data structure."
  [xs]
-  (in xs (- (length xs) 1)))
+  (get xs (- (length xs) 1)))

 ###
 ###
@ -649,41 +668,54 @@
 ###
 ###

-(def sort
-  "(sort xs [, by])\n\nSort an array in-place. Uses quick-sort and is not a stable sort."
-  (do
+(defn- sort-part
+  [a lo hi by]
+  (def pivot (in a hi))
+  (var i lo)
+  (for j lo hi
+    (def aj (in a j))
+    (when (by aj pivot)
+      (def ai (in a i))
+      (set (a i) aj)
+      (set (a j) ai)
+      (++ i)))
+  (set (a hi) (in a i))
+  (set (a i) pivot)
+  i)

-    (defn part
-      [a lo hi by]
-      (def pivot (in a hi))
-      (var i lo)
-      (for j lo hi
-        (def aj (in a j))
-        (when (by aj pivot)
-          (def ai (in a i))
-          (set (a i) aj)
-          (set (a j) ai)
-          (++ i)))
-      (set (a hi) (in a i))
-      (set (a i) pivot)
-      i)
+(defn- sort-help
+  [a lo hi by]
+  (when (> hi lo)
+    (def piv (sort-part a lo hi by))
+    (sort-help a lo (- piv 1) by)
+    (sort-help a (+ piv 1) hi by))
+  a)

-    (defn sort-help
-      [a lo hi by]
-      (when (> hi lo)
-        (def piv (part a lo hi by))
-        (sort-help a lo (- piv 1) by)
-        (sort-help a (+ piv 1) hi by))
-      a)
+(defn sort
+  "Sort an array in-place. Uses quick-sort and is not a stable sort."
+  [a &opt by]
+  (sort-help a 0 (- (length a) 1) (or by <)))

-    (fn sort [a &opt by]
-      (sort-help a 0 (- (length a) 1) (or by <)))))
+(put _env 'sort-part nil)
+(put _env 'sort-help nil)
+
+(defn sort-by
+  "Returns a new sorted array that compares elements by invoking
+  a function on each element and comparing the result with <."
+  [f ind]
+  (sort ind (fn [x y] (< (f x) (f y)))))

 (defn sorted
  "Returns a new sorted array without modifying the old one."
  [ind &opt by]
  (sort (array/slice ind) by))

+(defn sorted-by
+  "Returns a new sorted array that compares elements by invoking
+  a function on each element and comparing the result with <."
+  [f ind]
+  (sorted ind (fn [x y] (< (f x) (f y)))))
+
 (defn reduce
  "Reduce, also know as fold-left in many languages, transforms
  an indexed type (array, tuple) with a function to produce a value."
@ -692,6 +724,45 @@
  (each x ind (set res (f res x)))
  res)

+(defn reduce2
+  "The 2 argument version of reduce that does not take an initialization value.
+  Instead the first element of the array is used for initialization."
+  [f ind]
+  (var k (next ind))
+  (if (= nil k) (break nil))
+  (var res (in ind k))
+  (set k (next ind k))
+  (while (not= nil k)
+    (set res (f res (in ind k)))
+    (set k (next ind k)))
+  res)
+
+(defn accumulate
+  "Similar to reduce, but accumulates intermediate values into an array.
+  The last element in the array is what would be the return value from reduce.
+  The init value is not added to the array.
+  Returns a new array."
+  [f init ind]
+  (var res init)
+  (def ret (array/new (length ind)))
+  (each x ind (array/push ret (set res (f res x))))
+  ret)
+
+(defn accumulate2
+  "The 2 argument version of accumulate that does not take an initialization value."
+  [f ind]
+  (var k (next ind))
+  (def ret (array/new (length ind)))
+  (if (= nil k) (break ret))
+  (var res (in ind k))
+  (array/push ret res)
+  (set k (next ind k))
+  (while (not= nil k)
+    (set res (f res (in ind k)))
+    (array/push ret res)
+    (set k (next ind k)))
+  ret)
+
 (defn map
  "Map a function over every element in an indexed data structure and
  return an array of the results."
@ -896,7 +967,7 @@
  (reduce fop x forms))

 (defmacro -?>
-  "Short circuit threading macro. Inserts x as the last value in the first form
+  "Short circuit threading macro. Inserts x as the second value in the first form
  in forms, and inserts the modified first form into the second form
  in the same manner, and so on. The pipeline will return nil
  if an intermediate value is nil.
@ -912,7 +983,7 @@
  (reduce fop x forms))

 (defmacro -?>>
-  "Threading macro. Inserts x as the last value in the first form
+  "Short circuit threading macro. Inserts x as the last value in the first form
  in forms, and inserts the modified first form into the second form
  in the same manner, and so on. The pipeline will return nil
  if an intermediate value is nil.
@ -1411,10 +1482,10 @@
 ###

 (defn- env-walk
-  [pred &opt env]
+  [pred &opt env local]
  (default env (fiber/getenv (fiber/current)))
  (def envs @[])
-  (do (var e env) (while e (array/push envs e) (set e (table/getproto e))))
+  (do (var e env) (while e (array/push envs e) (set e (table/getproto e)) (if local (break))))
  (def ret-set @{})
  (loop [envi :in envs
         k :keys envi
@ -1423,22 +1494,24 @@
  (sort (keys ret-set)))

 (defn all-bindings
-  "Get all symbols available in an enviroment. Defaults to the current
-  fiber's environment."
-  [&opt env]
-  (env-walk symbol? env))
+  "Get all symbols available in an environment. Defaults to the current
+  fiber's environment. If local is truthy, will not show inherited bindings
+  (from prototype tables)."
+  [&opt env local]
+  (env-walk symbol? env local))

 (defn all-dynamics
  "Get all dynamic bindings in an environment. Defaults to the current
-  fiber's environment."
-  [&opt env]
-  (env-walk keyword? env))
+  fiber's environment. If local is truthy, will not show inherited bindings
+  (from prototype tables)."
+  [&opt env local]
+  (env-walk keyword? env local))

 (defn doc-format
  "Reformat text to wrap at a given line."
-  [text]
+  [text &opt width]

-  (def maxcol (- (dyn :doc-width 80) 8))
+  (def maxcol (- (or width (dyn :doc-width 80)) 8))
  (var buf @"    ")
  (var word @"")
  (var current 0)
@ -1630,7 +1703,7 @@
  ret)

 (defn all
-  "Returns true if all xs are truthy, otherwise the resulty of first
+  "Returns true if all xs are truthy, otherwise the result of first
  falsey predicate value, (pred x)."
  [pred xs]
  (var ret true)
@ -1844,8 +1917,9 @@
  (eflush))

 (defn run-context
-  "Run a context. This evaluates expressions of janet in an environment,
+  "Run a context. This evaluates expressions in an environment,
  and is encapsulates the parsing, compilation, and evaluation.
+  Returns (in environment :exit-value environment) when complete.
  opts is a table or struct of options. The options are as follows:\n\n\t
  :chunks - callback to read into a buffer - default is getline\n\t
  :on-parse-error - callback when parsing fails - default is bad-parse\n\t
@ -2104,13 +2178,15 @@
  @{})

 (defn dofile
-  "Evaluate a file and return the resulting environment."
-  [path & args]
-  (def {:exit exit-on-error
-        :source source
-        :env env
-        :expander expander
-        :evaluator evaluator} (table ;args))
+  "Evaluate a file and return the resulting environment. :env, :expander, and
+  :evaluator are passed through to the underlying run-context call.
+  If exit is true, any top level errors will trigger a call to (os/exit 1)
+  after printing the error."
+  [path &keys
+   {:exit exit
+    :env env
+    :expander expander
+    :evaluator evaluator}]
  (def f (if (= (type path) :core/file)
           path
           (file/open path :rb)))
@ -2122,11 +2198,11 @@
  (defn chunks [buf _] (file/read f 2048 buf))
  (defn bp [&opt x y]
    (def ret (bad-parse x y))
-    (if exit-on-error (os/exit 1))
+    (if exit (os/exit 1))
    ret)
  (defn bc [&opt x y z]
    (def ret (bad-compile x y z))
-    (if exit-on-error (os/exit 1))
+    (if exit (os/exit 1))
    ret)
  (unless f
    (error (string "could not find file " path)))
@ -2138,7 +2214,7 @@
                  :on-status (fn [f x]
                               (when (not= (fiber/status f) :dead)
                                 (debug/stacktrace f x)
-                                 (if exit-on-error (os/exit 1) (eflush))))
+                                 (if exit (os/exit 1) (eflush))))
                  :evaluator evaluator
                  :expander expander
                  :source (if path-is-file "<anonymous>" spath)}))
@ -2199,18 +2275,171 @@
  any errors encountered at the top level in the module will cause (os/exit 1)
  to be called. Dynamic bindings will NOT be imported."
  [path & args]
-  (def argm (map (fn [x]
-                   (if (keyword? x)
-                     x
-                     (string x)))
-                 args))
+  (def argm (map |(if (keyword? $) $ (string $)) args))
  (tuple import* (string path) ;argm))

 (defmacro use
  "Similar to import, but imported bindings are not prefixed with a namespace
  identifier. Can also import multiple modules in one shot."
  [& modules]
-  ~(do ,;(map (fn [x] ~(,import* ,(string x) :prefix "")) modules)))
+  ~(do ,;(map |~(,import* ,(string $) :prefix "") modules)))
+
+###
+###
+### Debugger
+###
+###
+
+(defn .fiber
+  "Get the current fiber being debugged."
+  []
+  (dyn :fiber))
+
+(defn .signal
+  "Get the current signal being debugged."
+  []
+  (dyn :signal))
+
+(defn .stack
+  "Print the current fiber stack"
+  []
+  (print)
+  (with-dyns [:err-color false] (debug/stacktrace (.fiber) (.signal)))
+  (print))
+
+(defn .frame
+  "Show a stack frame"
+  [&opt n]
+  (def stack (debug/stack (.fiber)))
+  (in stack (or n 0)))
+
+(defn .fn
+  "Get the current function"
+  [&opt n]
+  (in (.frame n) :function))
+
+(defn .slots
+  "Get an array of slots in a stack frame"
+  [&opt n]
+  (in (.frame n) :slots))
+
+(defn .slot
+  "Get the value of the nth slot."
+  [&opt nth frame-idx]
+  (in (.slots frame-idx) (or nth 0)))
+
+(defn .disasm
+  "Gets the assembly for the current function."
+  [&opt n]
+  (def frame (.frame n))
+  (def func (frame :function))
+  (disasm func))
+
+(defn .bytecode
+  "Get the bytecode for the current function."
+  [&opt n]
+  ((.disasm n) 'bytecode))
+
+(defn .ppasm
+  "Pretty prints the assembly for the current function"
+  [&opt n]
+  (def frame (.frame n))
+  (def func (frame :function))
+  (def dasm (disasm func))
+  (def bytecode (dasm 'bytecode))
+  (def pc (frame :pc))
+  (def sourcemap (dasm 'sourcemap))
+  (var last-loc [-2 -2])
+  (print "\n  signal: " (.signal))
+  (print "  function:   " (dasm 'name) " [" (in dasm 'source "") "]")
+  (when-let [constants (dasm 'constants)]
+    (printf "  constants:  %.4q" constants))
+  (printf "  slots:      %.4q\n" (frame :slots))
+  (def padding (string/repeat " " 20))
+  (loop [i :range [0 (length bytecode)]
+         :let [instr (bytecode i)]]
+    (prin (if (= (tuple/type instr) :brackets) "*" " "))
+    (prin (if (= i pc) "> " "  "))
+    (prinf "%.20s" (string (string/join (map string instr) " ") padding))
+    (when sourcemap
+      (let [[sl sc] (sourcemap i)
+            loc [sl sc]]
+        (when (not= loc last-loc)
+          (set last-loc loc)
+          (prin " # line " sl ", column " sc))))
+    (print))
+  (print))
+
+(defn .source
+  "Show the source code for the function being debugged."
+  [&opt n]
+  (def frame (.frame n))
+  (def s (frame :source))
+  (def all-source (slurp s))
+  (print "\n" all-source "\n"))
+
+(defn .breakall
+  "Set breakpoints on all instructions in the current function."
+  [&opt n]
+  (def fun (.fn n))
+  (def bytecode (.bytecode n))
+  (for i 0 (length bytecode)
+    (debug/fbreak fun i))
+  (print "Set " (length bytecode) " breakpoints in " fun))
+
+(defn .clearall
+  "Clear all breakpoints on the current function."
+  [&opt n]
+  (def fun (.fn n))
+  (def bytecode (.bytecode n))
+  (for i 0 (length bytecode)
+    (debug/unfbreak fun i))
+  (print "Cleared " (length bytecode) " breakpoints in " fun))
+
+(defn .break
+  "Set breakpoint at the current pc."
+  []
+  (def frame (.frame))
+  (def fun (frame :function))
+  (def pc (frame :pc))
+  (debug/fbreak fun pc)
+  (print "Set breakpoint in " fun " at pc=" pc))
+
+(defn .clear
+  "Clear the current breakpoint"
+  []
+  (def frame (.frame))
+  (def fun (frame :function))
+  (def pc (frame :pc))
+  (debug/unfbreak fun pc)
+  (print "Cleared breakpoint in " fun " at pc=" pc))
+
+(defn .next
+  "Go to the next breakpoint."
+  [&opt n]
+  (var res nil)
+  (for i 0 (or n 1)
+    (set res (resume (.fiber))))
+  res)
+
+(defn .nextc
+  "Go to the next breakpoint, clearing the current breakpoint."
+  [&opt n]
+  (.clear)
+  (.next n))
+
+(defn .step
+  "Execute the next n instructions."
+  [&opt n]
+  (var res nil)
+  (for i 0 (or n 1)
+    (set res (debug/step (.fiber))))
+  res)
+
+(def- debugger-keys (filter (partial string/has-prefix? ".") (keys _env)))
+(def- debugger-env @{})
+(each k debugger-keys (put debugger-env k (_env k)) (put _env k nil))
+(put _env 'debugger-keys nil)

 ###
 ###
@ -2226,11 +2455,15 @@
  the repl in."
  [&opt chunks onsignal env]
  (default env (make-env))
-  (default chunks (fn [buf p] (getline (string "repl:"
-                                               ((parser/where p) 0)
-                                               ":"
-                                               (parser/state p :delimiters) "> ")
-                                       buf env)))
+  (default chunks
+    (fn [buf p]
+      (getline
+        (string
+          "repl:"
+          ((parser/where p) 0)
+          ":"
+          (parser/state p :delimiters) "> ")
+        buf env)))
  (defn make-onsignal
    [e level]

@ -2240,13 +2473,14 @@
      (put nextenv :fiber f)
      (put nextenv :debug-level level)
      (put nextenv :signal x)
+      (merge-into nextenv debugger-env)
      (debug/stacktrace f x)
      (eflush)
      (defn debugger-chunks [buf p]
        (def status (parser/state p :delimiters))
        (def c ((parser/where p) 0))
-        (def prompt (string "debug[" level "]:" c ":" status "> "))
-        (getline prompt buf nextenv))
+        (def prpt (string "debug[" level "]:" c ":" status "> "))
+        (getline prpt buf nextenv))
      (print "entering debug[" level "] - (quit) to exit")
      (flush)
      (repl debugger-chunks (make-onsignal nextenv (+ 1 level)) nextenv)
@ -2266,6 +2500,8 @@
                :on-status (or onsignal (make-onsignal env 1))
                :source "repl"}))

+(put _env 'debugger-env nil)
+
 ###
 ###
 ### CLI Tool Main
@ -2309,6 +2545,7 @@
  (var *handleopts* true)
  (var *exit-on-error* true)
  (var *colorize* true)
+  (var *debug* false)
  (var *compile-only* false)

  (if-let [jp (os/getenv "JANET_PATH")] (setdyn :syspath jp))
@ -2324,6 +2561,7 @@
  -v : Print the version string
  -s : Use raw stdin instead of getline like functionality
  -e code : Execute a string of janet
+  -d : Set the debug flag in the repl
  -r : Enter the repl after running all scripts
  -p : Keep on executing if there is a top level error (persistent)
  -q : Hide prompt, logo, and repl output (quiet)
@ -2356,7 +2594,8 @@
     "e" (fn [i &]
           (set *no-file* false)
           (eval-string (in args (+ i 1)))
-           2)})
+           2)
+     "d" (fn [&] (set *debug* true) 1)})

  (defn- dohandler [n i &]
    (def h (in handlers n))
@ -2415,6 +2654,7 @@
      (file/flush stdout)
      (file/read stdin :line buf))
    (def env (make-env))
+    (if *debug* (put env :debug true))
    (def getter (if *raw-stdin* getstdin getline))
    (defn getchunk [buf p]
      (getter (prompter p) buf env))
@ -2435,7 +2675,7 @@
 ###
 ###

-(def root-env "The root environment used to create envionments with (make-env)" _env)
+(def root-env "The root environment used to create environments with (make-env)" _env)

 (do
  (put _env 'boot/opts nil)
@ -2483,9 +2723,10 @@

  # Create amalgamation

+  (def feature-header "src/core/features.h")
+
  (def local-headers
-    ["src/core/features.h"
-     "src/core/util.h"
+    ["src/core/util.h"
     "src/core/state.h"
     "src/core/gc.h"
     "src/core/vector.h"
@ -2540,21 +2781,23 @@
  (print "/* Generated from janet version " janet/version "-" janet/build " */")
  (print "#define JANET_BUILD \"" janet/build "\"")
  (print ```#define JANET_AMALG```)
-  (print ```#define _POSIX_C_SOURCE 200112L```)
-  (print ```#include "janet.h"```)

-  (defn do-one-flie
+  (defn do-one-file
    [fname]
    (print "\n/* " fname " */")
    (print "#line 0 \"" fname "\"\n")
    (def source (slurp fname))
    (print (string/replace-all "\r" "" source)))

+  (do-one-file feature-header)
+
+  (print ```#include "janet.h"```)
+
  (each h local-headers
-    (do-one-flie h))
+    (do-one-file h))

  (each s core-sources
-    (do-one-flie s))
+    (do-one-file s))

  # Create C source file that contains images a uint8_t buffer. This
  # can be compiled and linked statically into the main janet library
--- a/src/conf/janetconf.h
+++ b/src/conf/janetconf.h
@ -27,10 +27,10 @@
 #define JANETCONF_H

 #define JANET_VERSION_MAJOR 1
-#define JANET_VERSION_MINOR 7
-#define JANET_VERSION_PATCH 1
-#define JANET_VERSION_EXTRA "-dev"
-#define JANET_VERSION "1.7.1-dev"
+#define JANET_VERSION_MINOR 9
+#define JANET_VERSION_PATCH 0
+#define JANET_VERSION_EXTRA ""
+#define JANET_VERSION "1.9.0-dev"

 /* #define JANET_BUILD "local" */

--- a/src/core/asm.c
+++ b/src/core/asm.c
@ -707,6 +707,9 @@ static JanetAssembleResult janet_asm1(JanetAssembler *parent, Janet source, int
    if (janet_indexed_view(x, &arr, &count)) {
        janet_asm_assert(&a, count == def->bytecode_length, "sourcemap must have the same length as the bytecode");
        def->sourcemap = malloc(sizeof(JanetSourceMapping) * (size_t) count);
+        if (NULL == def->sourcemap) {
+            JANET_OUT_OF_MEMORY;
+        }
        for (i = 0; i < count; i++) {
            const Janet *tup;
            Janet entry = arr[i];
@ -730,6 +733,9 @@ static JanetAssembleResult janet_asm1(JanetAssembler *parent, Janet source, int
    /* Set environments */
    def->environments =
        realloc(def->environments, def->environments_length * sizeof(int32_t));
+    if (NULL == def->environments) {
+        JANET_OUT_OF_MEMORY;
+    }

    /* Verify the func def */
    if (janet_verify(def)) {
--- a/src/core/buffer.c
+++ b/src/core/buffer.c
@ -334,13 +334,15 @@ static Janet cfun_buffer_blit(int32_t argc, Janet *argv) {
    } else {
        length_src = src.len - offset_src;
    }
-    int64_t last = ((int64_t) offset_dest - offset_src) + length_src;
+    int64_t last = (int64_t) offset_dest + length_src;
    if (last > INT32_MAX)
        janet_panic("buffer blit out of range");
-    janet_buffer_ensure(dest, (int32_t) last, 2);
-    if (last > dest->count) dest->count = (int32_t) last;
+    int32_t last32 = (int32_t) last;
+    janet_buffer_ensure(dest, last32, 2);
+    if (last32 > dest->count) dest->count = last32;
    if (length_src) {
        if (same_buf) {
+            /* janet_buffer_ensure may have invalidated src */
            src.bytes = dest->data;
            memmove(dest->data + offset_dest, src.bytes + offset_src, length_src);
        } else {
@ -438,7 +440,7 @@ static const JanetReg buffer_cfuns[] = {
    },
    {
        "buffer/blit", cfun_buffer_blit,
-        JDOC("(buffer/blit dest src & opt dest-start src-start src-end)\n\n"
+        JDOC("(buffer/blit dest src &opt dest-start src-start src-end)\n\n"
             "Insert the contents of src into dest. Can optionally take indices that "
             "indicate which part of src to copy into which part of dest. Indices can be "
             "negative to index from the end of src or dest. Returns dest.")
--- a/src/core/bytecode.c
+++ b/src/core/bytecode.c
@ -212,6 +212,7 @@ JanetFuncDef *janet_funcdef_alloc(void) {
    def->environments = NULL;
    def->constants = NULL;
    def->bytecode = NULL;
+    def->closure_bitset = NULL;
    def->flags = 0;
    def->slotcount = 0;
    def->arity = 0;
--- a/src/core/capi.c
+++ b/src/core/capi.c
@ -54,7 +54,7 @@ void janet_panicf(const char *format, ...) {
    while (format[len]) len++;
    janet_buffer_init(&buffer, len);
    va_start(args, format);
-    janet_formatb(&buffer, format, args);
+    janet_formatbv(&buffer, format, args);
    va_end(args);
    ret = janet_string(buffer.data, buffer.count);
    janet_buffer_deinit(&buffer);
@ -235,18 +235,20 @@ size_t janet_getsize(const Janet *argv, int32_t n) {

 int32_t janet_gethalfrange(const Janet *argv, int32_t n, int32_t length, const char *which) {
    int32_t raw = janet_getinteger(argv, n);
-    if (raw < 0) raw += length + 1;
-    if (raw < 0 || raw > length)
-        janet_panicf("%s index %d out of range [0,%d]", which, raw, length);
-    return raw;
+    int32_t not_raw = raw;
+    if (not_raw < 0) not_raw += length + 1;
+    if (not_raw < 0 || not_raw > length)
+        janet_panicf("%s index %d out of range [%d,%d]", which, raw, -length - 1, length);
+    return not_raw;
 }

 int32_t janet_getargindex(const Janet *argv, int32_t n, int32_t length, const char *which) {
    int32_t raw = janet_getinteger(argv, n);
-    if (raw < 0) raw += length;
-    if (raw < 0 || raw > length)
-        janet_panicf("%s index %d out of range [0,%d)", which, raw, length);
-    return raw;
+    int32_t not_raw = raw;
+    if (not_raw < 0) not_raw += length;
+    if (not_raw < 0 || not_raw > length)
+        janet_panicf("%s index %d out of range [%d,%d)", which, raw, -length, length);
+    return not_raw;
 }

 JanetView janet_getindexed(const Janet *argv, int32_t n) {
--- a/src/core/compile.c
+++ b/src/core/compile.c
@ -102,6 +102,7 @@ void janetc_scope(JanetScope *s, JanetCompiler *c, int flags, const char *name)
    scope.bytecode_start = janet_v_count(c->buffer);
    scope.flags = flags;
    scope.parent = c->scope;
+    janetc_regalloc_init(&scope.ua);
    /* Inherit slots */
    if ((!(flags & JANET_SCOPE_FUNCTION)) && c->scope) {
        janetc_regalloc_clone(&scope.ra, &(c->scope->ra));
@ -149,6 +150,7 @@ void janetc_popscope(JanetCompiler *c) {
    janet_v_free(oldscope->envs);
    janet_v_free(oldscope->defs);
    janetc_regalloc_deinit(&oldscope->ra);
+    janetc_regalloc_deinit(&oldscope->ua);
    /* Update pointer */
    if (newscope)
        newscope->child = NULL;
@ -236,6 +238,11 @@ found:
        scope = scope->parent;
    janet_assert(scope, "invalid scopes");
    scope->flags |= JANET_SCOPE_ENV;
+
+    /* In the function scope, allocate the slot as an upvalue */
+    janetc_regalloc_touch(&scope->ua, ret.index);
+
+    /* Iterate through child scopes and make sure environment is propagated */
    scope = scope->child;

    /* Propagate env up to current scope */
@ -737,6 +744,21 @@ JanetFuncDef *janetc_pop_funcdef(JanetCompiler *c) {
        def->flags |= JANET_FUNCDEF_FLAG_NEEDSENV;
    }

+    /* Copy upvalue bitset */
+    if (scope->ua.count) {
+        /* Number of u32s we need to create a bitmask for all slots */
+        int32_t numchunks = (def->slotcount + 31) >> 5;
+        uint32_t *chunks = malloc(sizeof(uint32_t) * numchunks);
+        if (NULL == chunks) {
+            JANET_OUT_OF_MEMORY;
+        }
+        memcpy(chunks, scope->ua.chunks, sizeof(uint32_t) * numchunks);
+        /* Register allocator preallocates some registers [240-255, high 16 bits of chunk index 7], we can ignore those. */
+        if (scope->ua.count > 7) chunks[7] &= 0xFFFFU;
+        def->closure_bitset = chunks;
+        def->flags |= JANET_FUNCDEF_FLAG_HASCLOBITSET;
+    }
+
    /* Pop the scope */
    janetc_popscope(c);

--- a/src/core/compile.h
+++ b/src/core/compile.h
@ -127,7 +127,10 @@ struct JanetScope {
    /* Regsiter allocator */
    JanetcRegisterAllocator ra;

-    /* Referenced closure environents. The values at each index correspond
+    /* Upvalue allocator */
+    JanetcRegisterAllocator ua;
+
+    /* Referenced closure environments. The values at each index correspond
     * to which index to get the environment from in the parent. The environment
     * that corresponds to the direct parent's stack will always have value 0. */
    int32_t *envs;
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@ -435,7 +435,7 @@ static Janet janet_core_hash(int32_t argc, Janet *argv) {
 static Janet janet_core_getline(int32_t argc, Janet *argv) {
    FILE *in = janet_dynfile("in", stdin);
    FILE *out = janet_dynfile("out", stdout);
-    janet_arity(argc, 0, 2);
+    janet_arity(argc, 0, 3);
    JanetBuffer *buf = (argc >= 2) ? janet_getbuffer(argv, 1) : janet_buffer(10);
    if (argc >= 1) {
        const char *prompt = (const char *) janet_getstring(argv, 0);
@ -646,7 +646,7 @@ static const JanetReg corelib_cfuns[] = {
        "getline", janet_core_getline,
        JDOC("(getline &opt prompt buf env)\n\n"
             "Reads a line of input into a buffer, including the newline character, using a prompt. "
-             "An optional environment table can be provided for autocomplete. "
+             "An optional environment table can be provided for auto-complete. "
             "Returns the modified buffer. "
             "Use this function to implement a simple interface for a terminal program.")
    },
@ -680,7 +680,7 @@ static const JanetReg corelib_cfuns[] = {
             "\t:all:\tthe value of path verbatim\n"
             "\t:cur:\tthe current file, or (dyn :current-file)\n"
             "\t:dir:\tthe directory containing the current file\n"
-             "\t:name:\tthe filename component of path, with extenion if given\n"
+             "\t:name:\tthe filename component of path, with extension if given\n"
             "\t:native:\tthe extension used to load natives, .so or .dll\n"
             "\t:sys:\tthe system path, or (syn :syspath)")
    },
@ -697,7 +697,7 @@ static const JanetReg corelib_cfuns[] = {
    {
        "slice", janet_core_slice,
        JDOC("(slice x &opt start end)\n\n"
-             "Extract a sub-range of an indexed data strutrue or byte sequence.")
+             "Extract a sub-range of an indexed data structure or byte sequence.")
    },
    {
        "signal", janet_core_signal,
--- a/src/core/features.h
+++ b/src/core/features.h
@ -29,4 +29,9 @@
 #define _POSIX_C_SOURCE 200112L
 #endif

+/* Needed for realpath on linux */
+#if !defined(_XOPEN_SOURCE) && (defined(__linux__) || defined(__EMSCRIPTEN__))
+#define _XOPEN_SOURCE 500
+#endif
+
 #endif
--- a/src/core/fiber.c
+++ b/src/core/fiber.c
@ -218,18 +218,79 @@ int janet_fiber_funcframe(JanetFiber *fiber, JanetFunction *func) {
 static void janet_env_detach(JanetFuncEnv *env) {
    /* Check for closure environment */
    if (env) {
-        size_t s = sizeof(Janet) * (size_t) env->length;
+        janet_env_valid(env);
+        int32_t len = env->length;
+        size_t s = sizeof(Janet) * (size_t) len;
        Janet *vmem = malloc(s);
        janet_vm_next_collection += (uint32_t) s;
        if (NULL == vmem) {
            JANET_OUT_OF_MEMORY;
        }
-        safe_memcpy(vmem, env->as.fiber->data + env->offset, s);
+        Janet *values = env->as.fiber->data + env->offset;
+        safe_memcpy(vmem, values, s);
+        uint32_t *bitset = janet_stack_frame(values)->func->def->closure_bitset;
+        if (bitset) {
+            /* Clear unneeded references in closure environment */
+            for (int32_t i = 0; i < len; i += 32) {
+                uint32_t mask = ~(bitset[i >> 5]);
+                int32_t maxj = i + 32 > len ? len : i + 32;
+                for (int32_t j = i; j < maxj; j++) {
+                    if (mask & 1) vmem[j] = janet_wrap_nil();
+                    mask >>= 1;
+                }
+            }
+        }
        env->offset = 0;
        env->as.values = vmem;
    }
 }

+/* Validate potentially untrusted func env (unmarshalled envs are difficult to verify) */
+int janet_env_valid(JanetFuncEnv *env) {
+    if (env->offset < 0) {
+        int32_t real_offset = -(env->offset);
+        JanetFiber *fiber = env->as.fiber;
+        int32_t i = fiber->frame;
+        while (i > 0) {
+            JanetStackFrame *frame = (JanetStackFrame *)(fiber->data + i - JANET_FRAME_SIZE);
+            if (real_offset == i &&
+                    frame->env == env &&
+                    frame->func &&
+                    frame->func->def->slotcount == env->length) {
+                env->offset = real_offset;
+                return 1;
+            }
+            i = frame->prevframe;
+        }
+        /* Invalid, set to empty off-stack variant. */
+        env->offset = 0;
+        env->length = 0;
+        env->as.values = NULL;
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
+/* Detach a fiber from the env if the target fiber has stopped mutating */
+void janet_env_maybe_detach(JanetFuncEnv *env) {
+    /* Check for detachable closure envs */
+    janet_env_valid(env);
+    if (env->offset > 0) {
+        JanetFiberStatus s = janet_fiber_status(env->as.fiber);
+        int isFinished = s == JANET_STATUS_DEAD ||
+                         s == JANET_STATUS_ERROR ||
+                         s == JANET_STATUS_USER0 ||
+                         s == JANET_STATUS_USER1 ||
+                         s == JANET_STATUS_USER2 ||
+                         s == JANET_STATUS_USER3 ||
+                         s == JANET_STATUS_USER4;
+        if (isFinished) {
+            janet_env_detach(env);
+        }
+    }
+}
+
 /* Create a tail frame for a function */
 int janet_fiber_funcframe_tail(JanetFiber *fiber, JanetFunction *func) {
    int32_t i;
--- a/src/core/fiber.h
+++ b/src/core/fiber.h
@ -73,5 +73,7 @@ int janet_fiber_funcframe(JanetFiber *fiber, JanetFunction *func);
 int janet_fiber_funcframe_tail(JanetFiber *fiber, JanetFunction *func);
 void janet_fiber_cframe(JanetFiber *fiber, JanetCFunction cfun);
 void janet_fiber_popframe(JanetFiber *fiber);
+void janet_env_maybe_detach(JanetFuncEnv *env);
+int janet_env_valid(JanetFuncEnv *env);

 #endif
--- a/src/core/gc.c
+++ b/src/core/gc.c
@ -27,6 +27,7 @@
 #include "symcache.h"
 #include "gc.h"
 #include "util.h"
+#include "fiber.h"
 #endif

 struct JanetScratch {
@ -189,7 +190,10 @@ static void janet_mark_funcenv(JanetFuncEnv *env) {
    if (janet_gc_reachable(env))
        return;
    janet_gc_mark(env);
-    if (env->offset) {
+    /* If closure env references a dead fiber, we can just copy out the stack frame we need so
+     * we don't need to keep around the whole dead fiber. */
+    janet_env_maybe_detach(env);
+    if (env->offset > 0) {
        /* On stack */
        janet_mark_fiber(env->as.fiber);
    } else {
@ -305,6 +309,7 @@ static void janet_deinit_block(JanetGCObject *mem) {
            free(def->constants);
            free(def->bytecode);
            free(def->sourcemap);
+            free(def->closure_bitset);
        }
        break;
    }
--- a/src/core/inttypes.c
+++ b/src/core/inttypes.c
@ -81,7 +81,7 @@ static void it_u64_tostring(void *p, JanetBuffer *buffer) {
    janet_buffer_push_cstring(buffer, str);
 }

-static const JanetAbstractType it_s64_type = {
+const JanetAbstractType janet_s64_type = {
    "core/s64",
    NULL,
    NULL,
@ -95,7 +95,7 @@ static const JanetAbstractType it_s64_type = {
    JANET_ATEND_HASH
 };

-static const JanetAbstractType it_u64_type = {
+const JanetAbstractType janet_u64_type = {
    "core/u64",
    NULL,
    NULL,
@ -128,8 +128,8 @@ int64_t janet_unwrap_s64(Janet x) {
        }
        case JANET_ABSTRACT: {
            void *abst = janet_unwrap_abstract(x);
-            if (janet_abstract_type(abst) == &it_s64_type ||
-                    (janet_abstract_type(abst) == &it_u64_type))
+            if (janet_abstract_type(abst) == &janet_s64_type ||
+                    (janet_abstract_type(abst) == &janet_u64_type))
                return *(int64_t *)abst;
            break;
        }
@ -157,8 +157,8 @@ uint64_t janet_unwrap_u64(Janet x) {
        }
        case JANET_ABSTRACT: {
            void *abst = janet_unwrap_abstract(x);
-            if (janet_abstract_type(abst) == &it_s64_type ||
-                    (janet_abstract_type(abst) == &it_u64_type))
+            if (janet_abstract_type(abst) == &janet_s64_type ||
+                    (janet_abstract_type(abst) == &janet_u64_type))
                return *(uint64_t *)abst;
            break;
        }
@ -170,19 +170,19 @@ uint64_t janet_unwrap_u64(Janet x) {
 JanetIntType janet_is_int(Janet x) {
    if (!janet_checktype(x, JANET_ABSTRACT)) return JANET_INT_NONE;
    const JanetAbstractType *at = janet_abstract_type(janet_unwrap_abstract(x));
-    return (at == &it_s64_type) ? JANET_INT_S64 :
-           ((at == &it_u64_type) ? JANET_INT_U64 :
+    return (at == &janet_s64_type) ? JANET_INT_S64 :
+           ((at == &janet_u64_type) ? JANET_INT_U64 :
            JANET_INT_NONE);
 }

 Janet janet_wrap_s64(int64_t x) {
-    int64_t *box = janet_abstract(&it_s64_type, sizeof(int64_t));
+    int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
    *box = (int64_t)x;
    return janet_wrap_abstract(box);
 }

 Janet janet_wrap_u64(uint64_t x) {
-    uint64_t *box = janet_abstract(&it_u64_type, sizeof(uint64_t));
+    uint64_t *box = janet_abstract(&janet_u64_type, sizeof(uint64_t));
    *box = (uint64_t)x;
    return janet_wrap_abstract(box);
 }
@ -200,7 +200,7 @@ static Janet cfun_it_u64_new(int32_t argc, Janet *argv) {
 #define OPMETHOD(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_arity(argc, 2, -1); \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[0]); \
    for (int32_t i = 1; i < argc; i++) \
        *box oper##= janet_unwrap_##type(argv[i]); \
@ -210,7 +210,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define OPMETHODINVERT(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_fixarity(argc, 2); \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[1]); \
    *box oper##= janet_unwrap_##type(argv[0]); \
    return janet_wrap_abstract(box); \
@ -219,7 +219,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define DIVMETHOD(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_arity(argc, 2, -1);                       \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[0]); \
    for (int32_t i = 1; i < argc; i++) { \
      T value = janet_unwrap_##type(argv[i]); \
@ -232,7 +232,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define DIVMETHODINVERT(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_fixarity(argc, 2);                       \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[1]); \
    T value = janet_unwrap_##type(argv[0]); \
    if (value == 0) janet_panic("division by zero"); \
@ -243,7 +243,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define DIVMETHOD_SIGNED(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_arity(argc, 2, -1);                       \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[0]); \
    for (int32_t i = 1; i < argc; i++) { \
      T value = janet_unwrap_##type(argv[i]); \
@ -257,7 +257,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 #define DIVMETHODINVERT_SIGNED(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
    janet_fixarity(argc, 2);                       \
-    T *box = janet_abstract(&it_##type##_type, sizeof(T)); \
+    T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
    *box = janet_unwrap_##type(argv[1]); \
    T value = janet_unwrap_##type(argv[0]); \
    if (value == 0) janet_panic("division by zero"); \
@ -276,7 +276,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \

 static Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, -1);
-    int64_t *box = janet_abstract(&it_s64_type, sizeof(int64_t));
+    int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
    *box = janet_unwrap_s64(argv[0]);
    for (int32_t i = 1; i < argc; i++) {
        int64_t value = janet_unwrap_s64(argv[i]);
@ -292,7 +292,7 @@ static Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {

 static Janet cfun_it_s64_modi(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 2);
-    int64_t *box = janet_abstract(&it_s64_type, sizeof(int64_t));
+    int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
    int64_t op1 = janet_unwrap_s64(argv[0]);
    int64_t op2 = janet_unwrap_s64(argv[1]);
    int64_t x = op1 % op2;
@ -441,8 +441,8 @@ static const JanetReg it_cfuns[] = {
 /* Module entry point */
 void janet_lib_inttypes(JanetTable *env) {
    janet_core_cfuns(env, NULL, it_cfuns);
-    janet_register_abstract_type(&it_s64_type);
-    janet_register_abstract_type(&it_u64_type);
+    janet_register_abstract_type(&janet_s64_type);
+    janet_register_abstract_type(&janet_u64_type);
 }

 #endif
--- a/src/core/io.c
+++ b/src/core/io.c
@ -33,16 +33,10 @@
 #include <sys/wait.h>
 #endif

-typedef struct IOFile IOFile;
-struct IOFile {
-    FILE *file;
-    int flags;
-};
-
 static int cfun_io_gc(void *p, size_t len);
 static int io_file_get(void *p, Janet key, Janet *out);

-JanetAbstractType cfun_io_filetype = {
+const JanetAbstractType janet_file_type = {
    "core/file",
    cfun_io_gc,
    NULL,
@ -90,7 +84,7 @@ static int checkflags(const uint8_t *str) {
 }

 static Janet makef(FILE *f, int flags) {
-    IOFile *iof = (IOFile *) janet_abstract(&cfun_io_filetype, sizeof(IOFile));
+    JanetFile *iof = (JanetFile *) janet_abstract(&janet_file_type, sizeof(JanetFile));
    iof->file = f;
    iof->flags = flags;
    return janet_wrap_abstract(iof);
@ -158,7 +152,7 @@ static Janet cfun_io_fopen(int32_t argc, Janet *argv) {
 }

 /* Read up to n bytes into buffer. */
-static void read_chunk(IOFile *iof, JanetBuffer *buffer, int32_t nBytesMax) {
+static void read_chunk(JanetFile *iof, JanetBuffer *buffer, int32_t nBytesMax) {
    if (!(iof->flags & (JANET_FILE_READ | JANET_FILE_UPDATE)))
        janet_panic("file is not readable");
    janet_buffer_extra(buffer, nBytesMax);
@ -172,7 +166,7 @@ static void read_chunk(IOFile *iof, JanetBuffer *buffer, int32_t nBytesMax) {
 /* Read a certain number of bytes into memory */
 static Janet cfun_io_fread(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, 3);
-    IOFile *iof = janet_getabstract(argv, 0, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, 0, &janet_file_type);
    if (iof->flags & JANET_FILE_CLOSED) janet_panic("file is closed");
    JanetBuffer *buffer;
    if (argc == 2) {
@ -212,7 +206,7 @@ static Janet cfun_io_fread(int32_t argc, Janet *argv) {
 /* Write bytes to a file */
 static Janet cfun_io_fwrite(int32_t argc, Janet *argv) {
    janet_arity(argc, 1, -1);
-    IOFile *iof = janet_getabstract(argv, 0, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, 0, &janet_file_type);
    if (iof->flags & JANET_FILE_CLOSED)
        janet_panic("file is closed");
    if (!(iof->flags & (JANET_FILE_WRITE | JANET_FILE_APPEND | JANET_FILE_UPDATE)))
@ -235,7 +229,7 @@ static Janet cfun_io_fwrite(int32_t argc, Janet *argv) {
 /* Flush the bytes in the file */
 static Janet cfun_io_fflush(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    IOFile *iof = janet_getabstract(argv, 0, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, 0, &janet_file_type);
    if (iof->flags & JANET_FILE_CLOSED)
        janet_panic("file is closed");
    if (!(iof->flags & (JANET_FILE_WRITE | JANET_FILE_APPEND | JANET_FILE_UPDATE)))
@ -248,7 +242,7 @@ static Janet cfun_io_fflush(int32_t argc, Janet *argv) {
 /* Cleanup a file */
 static int cfun_io_gc(void *p, size_t len) {
    (void) len;
-    IOFile *iof = (IOFile *)p;
+    JanetFile *iof = (JanetFile *)p;
    if (!(iof->flags & (JANET_FILE_NOT_CLOSEABLE | JANET_FILE_CLOSED))) {
        return fclose(iof->file);
    }
@ -258,7 +252,7 @@ static int cfun_io_gc(void *p, size_t len) {
 /* Close a file */
 static Janet cfun_io_fclose(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    IOFile *iof = janet_getabstract(argv, 0, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, 0, &janet_file_type);
    if (iof->flags & JANET_FILE_CLOSED)
        return janet_wrap_nil();
    if (iof->flags & (JANET_FILE_NOT_CLOSEABLE))
@ -282,7 +276,7 @@ static Janet cfun_io_fclose(int32_t argc, Janet *argv) {
 /* Seek a file */
 static Janet cfun_io_fseek(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, 3);
-    IOFile *iof = janet_getabstract(argv, 0, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, 0, &janet_file_type);
    if (iof->flags & JANET_FILE_CLOSED)
        janet_panic("file is closed");
    long int offset = 0;
@ -326,8 +320,8 @@ FILE *janet_dynfile(const char *name, FILE *def) {
    Janet x = janet_dyn(name);
    if (!janet_checktype(x, JANET_ABSTRACT)) return def;
    void *abstract = janet_unwrap_abstract(x);
-    if (janet_abstract_type(abstract) != &cfun_io_filetype) return def;
-    IOFile *iofile = abstract;
+    if (janet_abstract_type(abstract) != &janet_file_type) return def;
+    JanetFile *iofile = abstract;
    return iofile->file;
 }

@ -354,9 +348,9 @@ static Janet cfun_io_print_impl(int32_t argc, Janet *argv,
            break;
        case JANET_ABSTRACT: {
            void *abstract = janet_unwrap_abstract(x);
-            if (janet_abstract_type(abstract) != &cfun_io_filetype)
+            if (janet_abstract_type(abstract) != &janet_file_type)
                return janet_wrap_nil();
-            IOFile *iofile = abstract;
+            JanetFile *iofile = abstract;
            f = iofile->file;
            break;
        }
@ -421,9 +415,9 @@ static Janet cfun_io_printf_impl(int32_t argc, Janet *argv, int newline,
            break;
        case JANET_ABSTRACT: {
            void *abstract = janet_unwrap_abstract(x);
-            if (janet_abstract_type(abstract) != &cfun_io_filetype)
+            if (janet_abstract_type(abstract) != &janet_file_type)
                return janet_wrap_nil();
-            IOFile *iofile = abstract;
+            JanetFile *iofile = abstract;
            f = iofile->file;
            break;
        }
@ -470,8 +464,8 @@ static void janet_flusher(const char *name, FILE *dflt_file) {
            break;
        case JANET_ABSTRACT: {
            void *abstract = janet_unwrap_abstract(x);
-            if (janet_abstract_type(abstract) != &cfun_io_filetype) break;
-            IOFile *iofile = abstract;
+            if (janet_abstract_type(abstract) != &janet_file_type) break;
+            JanetFile *iofile = abstract;
            fflush(iofile->file);
            break;
        }
@ -508,12 +502,12 @@ void janet_dynprintf(const char *name, FILE *dflt_file, const char *format, ...)
            int32_t len = 0;
            while (format[len]) len++;
            janet_buffer_init(&buffer, len);
-            janet_formatb(&buffer, format, args);
+            janet_formatbv(&buffer, format, args);
            if (xtype == JANET_ABSTRACT) {
                void *abstract = janet_unwrap_abstract(x);
-                if (janet_abstract_type(abstract) != &cfun_io_filetype)
+                if (janet_abstract_type(abstract) != &janet_file_type)
                    break;
-                IOFile *iofile = abstract;
+                JanetFile *iofile = abstract;
                f = iofile->file;
            }
            fwrite(buffer.data, buffer.count, 1, f);
@ -521,7 +515,7 @@ void janet_dynprintf(const char *name, FILE *dflt_file, const char *format, ...)
            break;
        }
        case JANET_BUFFER:
-            janet_formatb(janet_unwrap_buffer(x), format, args);
+            janet_formatbv(janet_unwrap_buffer(x), format, args);
            break;
    }
    va_end(args);
@ -660,7 +654,7 @@ static const JanetReg io_cfuns[] = {
 /* C API */

 FILE *janet_getfile(const Janet *argv, int32_t n, int *flags) {
-    IOFile *iof = janet_getabstract(argv, n, &cfun_io_filetype);
+    JanetFile *iof = janet_getabstract(argv, n, &janet_file_type);
    if (NULL != flags) *flags = iof->flags;
    return iof->file;
 }
@ -670,11 +664,11 @@ Janet janet_makefile(FILE *f, int flags) {
 }

 JanetAbstract janet_checkfile(Janet j) {
-    return janet_checkabstract(j, &cfun_io_filetype);
+    return janet_checkabstract(j, &janet_file_type);
 }

 FILE *janet_unwrapfile(Janet j, int *flags) {
-    IOFile *iof = janet_unwrap_abstract(j);
+    JanetFile *iof = janet_unwrap_abstract(j);
    if (NULL != flags) *flags = iof->flags;
    return iof->file;
 }
--- a/src/core/marsh.c
+++ b/src/core/marsh.c
@ -42,26 +42,26 @@ typedef struct {
 /* Lead bytes in marshaling protocol */
 enum {
    LB_REAL = 200,
-    LB_NIL,
-    LB_FALSE,
-    LB_TRUE,
-    LB_FIBER,
-    LB_INTEGER,
-    LB_STRING,
-    LB_SYMBOL,
-    LB_KEYWORD,
-    LB_ARRAY,
-    LB_TUPLE,
-    LB_TABLE,
-    LB_TABLE_PROTO,
-    LB_STRUCT,
-    LB_BUFFER,
-    LB_FUNCTION,
-    LB_REGISTRY,
-    LB_ABSTRACT,
-    LB_REFERENCE,
-    LB_FUNCENV_REF,
-    LB_FUNCDEF_REF
+    LB_NIL, /* 201 */
+    LB_FALSE, /* 202 */
+    LB_TRUE,  /* 203 */
+    LB_FIBER, /* 204 */
+    LB_INTEGER, /* 205 */
+    LB_STRING, /* 206 */
+    LB_SYMBOL, /* 207 */
+    LB_KEYWORD, /* 208 */
+    LB_ARRAY, /* 209 */
+    LB_TUPLE, /* 210 */
+    LB_TABLE, /* 211 */
+    LB_TABLE_PROTO, /* 212 */
+    LB_STRUCT, /* 213 */
+    LB_BUFFER, /* 214 */
+    LB_FUNCTION, /* 215 */
+    LB_REGISTRY, /* 216 */
+    LB_ABSTRACT, /* 217 */
+    LB_REFERENCE, /* 218 */
+    LB_FUNCENV_REF, /* 219 */
+    LB_FUNCDEF_REF /* 220 */
 } LeadBytes;

 /* Helper to look inside an entry in an environment */
@ -183,16 +183,32 @@ static void marshal_one_env(MarshalState *st, JanetFuncEnv *env, int flags) {
            return;
        }
    }
+    janet_env_valid(env);
    janet_v_push(st->seen_envs, env);
-    pushint(st, env->offset);
-    pushint(st, env->length);
-    if (env->offset) {
-        /* On stack variant */
-        marshal_one(st, janet_wrap_fiber(env->as.fiber), flags + 1);
+    if (env->offset > 0 && (JANET_STATUS_ALIVE == janet_fiber_status(env->as.fiber))) {
+        pushint(st, 0);
+        pushint(st, env->length);
+        Janet *values = env->as.fiber->data + env->offset;
+        uint32_t *bitset = janet_stack_frame(values)->func->def->closure_bitset;
+        for (int32_t i = 0; i < env->length; i++) {
+            if (1 & (bitset[i >> 5] >> (i & 0x1F))) {
+                marshal_one(st, values[i], flags + 1);
+            } else {
+                pushbyte(st, LB_NIL);
+            }
+        }
    } else {
-        /* Off stack variant */
-        for (int32_t i = 0; i < env->length; i++)
-            marshal_one(st, env->as.values[i], flags + 1);
+        janet_env_maybe_detach(env);
+        pushint(st, env->offset);
+        pushint(st, env->length);
+        if (env->offset > 0) {
+            /* On stack variant */
+            marshal_one(st, janet_wrap_fiber(env->as.fiber), flags + 1);
+        } else {
+            /* Off stack variant */
+            for (int32_t i = 0; i < env->length; i++)
+                marshal_one(st, env->as.values[i], flags + 1);
+        }
    }
 }

@ -205,6 +221,16 @@ static void janet_func_addflags(JanetFuncDef *def) {
    if (def->sourcemap) def->flags |= JANET_FUNCDEF_FLAG_HASSOURCEMAP;
 }

+/* Marshal a sequence of u32s */
+static void janet_marshal_u32s(MarshalState *st, const uint32_t *u32s, int32_t n) {
+    for (int32_t i = 0; i < n; i++) {
+        pushbyte(st, u32s[i] & 0xFF);
+        pushbyte(st, (u32s[i] >> 8) & 0xFF);
+        pushbyte(st, (u32s[i] >> 16) & 0xFF);
+        pushbyte(st, (u32s[i] >> 24) & 0xFF);
+    }
+}
+
 /* Marshal a function def */
 static void marshal_one_def(MarshalState *st, JanetFuncDef *def, int flags) {
    MARSH_STACKCHECK;
@ -239,12 +265,7 @@ static void marshal_one_def(MarshalState *st, JanetFuncDef *def, int flags) {
        marshal_one(st, def->constants[i], flags);

    /* marshal the bytecode */
-    for (int32_t i = 0; i < def->bytecode_length; i++) {
-        pushbyte(st, def->bytecode[i] & 0xFF);
-        pushbyte(st, (def->bytecode[i] >> 8) & 0xFF);
-        pushbyte(st, (def->bytecode[i] >> 16) & 0xFF);
-        pushbyte(st, (def->bytecode[i] >> 24) & 0xFF);
-    }
+    janet_marshal_u32s(st, def->bytecode, def->bytecode_length);

    /* marshal the environments if needed */
    for (int32_t i = 0; i < def->environments_length; i++)
@ -264,6 +285,11 @@ static void marshal_one_def(MarshalState *st, JanetFuncDef *def, int flags) {
            current = map.line;
        }
    }
+
+    /* Marshal closure bitset, if needed */
+    if (def->flags & JANET_FUNCDEF_FLAG_HASCLOBITSET) {
+        janet_marshal_u32s(st, def->closure_bitset, ((def->slotcount + 31) >> 5));
+    }
 }

 #define JANET_FIBER_FLAG_HASCHILD (1 << 29)
@ -609,6 +635,15 @@ static int32_t readint(UnmarshalState *st, const uint8_t **atdata) {
    return ret;
 }

+/* Helper to read a natural number (int >= 0). */
+static int32_t readnat(UnmarshalState *st, const uint8_t **atdata) {
+    int32_t ret = readint(st, atdata);
+    if (ret < 0) {
+        janet_panicf("expected integer >= 0, got %d", ret);
+    }
+    return ret;
+}
+
 /* Helper to read a size_t (up to 8 bytes unsigned). */
 static uint64_t read64(UnmarshalState *st, const uint8_t **atdata) {
    uint64_t ret;
@ -677,36 +712,51 @@ static const uint8_t *unmarshal_one_env(
        JanetFuncEnv *env = janet_gcalloc(JANET_MEMORY_FUNCENV, sizeof(JanetFuncEnv));
        env->length = 0;
        env->offset = 0;
+        env->as.values = NULL;
        janet_v_push(st->lookup_envs, env);
-        int32_t offset = readint(st, &data);
-        int32_t length = readint(st, &data);
-        if (offset) {
+        int32_t offset = readnat(st, &data);
+        int32_t length = readnat(st, &data);
+        if (offset > 0) {
            Janet fiberv;
            /* On stack variant */
            data = unmarshal_one(st, data, &fiberv, flags);
            janet_asserttype(fiberv, JANET_FIBER);
            env->as.fiber = janet_unwrap_fiber(fiberv);
-            /* Unmarshalling fiber may set values */
-            if (env->offset != 0 && env->offset != offset)
-                janet_panic("invalid funcenv offset");
-            if (env->length != 0 && env->length != length)
-                janet_panic("invalid funcenv length");
+            /* Negative offset indicates untrusted input */
+            env->offset = -offset;
        } else {
            /* Off stack variant */
+            if (length == 0) {
+                janet_panic("invalid funcenv length");
+            }
            env->as.values = malloc(sizeof(Janet) * (size_t) length);
            if (!env->as.values) {
                JANET_OUT_OF_MEMORY;
            }
+            env->offset = 0;
            for (int32_t i = 0; i < length; i++)
                data = unmarshal_one(st, data, env->as.values + i, flags);
        }
-        env->offset = offset;
        env->length = length;
        *out = env;
    }
    return data;
 }

+/* Unmarshal a series of u32s */
+static const uint8_t *janet_unmarshal_u32s(UnmarshalState *st, const uint8_t *data, uint32_t *into, int32_t n) {
+    for (int32_t i = 0; i < n; i++) {
+        MARSH_EOS(st, data + 3);
+        into[i] =
+            (uint32_t)(data[0]) |
+            ((uint32_t)(data[1]) << 8) |
+            ((uint32_t)(data[2]) << 16) |
+            ((uint32_t)(data[3]) << 24);
+        data += 4;
+    }
+    return data;
+}
+
 /* Unmarshal a funcdef */
 static const uint8_t *unmarshal_one_def(
    UnmarshalState *st,
@ -730,6 +780,12 @@ static const uint8_t *unmarshal_one_def(
        def->bytecode_length = 0;
        def->name = NULL;
        def->source = NULL;
+        def->closure_bitset = NULL;
+        def->defs = NULL;
+        def->environments = NULL;
+        def->constants = NULL;
+        def->bytecode = NULL;
+        def->sourcemap = NULL;
        janet_v_push(st->lookup_defs, def);

        /* Set default lengths to zero */
@ -740,18 +796,18 @@ static const uint8_t *unmarshal_one_def(

        /* Read flags and other fixed values */
        def->flags = readint(st, &data);
-        def->slotcount = readint(st, &data);
-        def->arity = readint(st, &data);
-        def->min_arity = readint(st, &data);
-        def->max_arity = readint(st, &data);
+        def->slotcount = readnat(st, &data);
+        def->arity = readnat(st, &data);
+        def->min_arity = readnat(st, &data);
+        def->max_arity = readnat(st, &data);

        /* Read some lengths */
-        constants_length = readint(st, &data);
-        bytecode_length = readint(st, &data);
+        constants_length = readnat(st, &data);
+        bytecode_length = readnat(st, &data);
        if (def->flags & JANET_FUNCDEF_FLAG_HASENVS)
-            environments_length = readint(st, &data);
+            environments_length = readnat(st, &data);
        if (def->flags & JANET_FUNCDEF_FLAG_HASDEFS)
-            defs_length = readint(st, &data);
+            defs_length = readnat(st, &data);

        /* Check name and source (optional) */
        if (def->flags & JANET_FUNCDEF_FLAG_HASNAME) {
@ -785,15 +841,7 @@ static const uint8_t *unmarshal_one_def(
        if (!def->bytecode) {
            JANET_OUT_OF_MEMORY;
        }
-        for (int32_t i = 0; i < bytecode_length; i++) {
-            MARSH_EOS(st, data + 3);
-            def->bytecode[i] =
-                (uint32_t)(data[0]) |
-                ((uint32_t)(data[1]) << 8) |
-                ((uint32_t)(data[2]) << 16) |
-                ((uint32_t)(data[3]) << 24);
-            data += 4;
-        }
+        data = janet_unmarshal_u32s(st, data, def->bytecode, bytecode_length);
        def->bytecode_length = bytecode_length;

        /* Unmarshal environments */
@ -834,12 +882,21 @@ static const uint8_t *unmarshal_one_def(
            for (int32_t i = 0; i < bytecode_length; i++) {
                current += readint(st, &data);
                def->sourcemap[i].line = current;
-                def->sourcemap[i].column = readint(st, &data);
+                def->sourcemap[i].column = readnat(st, &data);
            }
        } else {
            def->sourcemap = NULL;
        }

+        /* Unmarshal closure bitset if needed */
+        if (def->flags & JANET_FUNCDEF_FLAG_HASCLOBITSET) {
+            def->closure_bitset = malloc(sizeof(uint32_t) * def->slotcount);
+            if (NULL == def->closure_bitset) {
+                JANET_OUT_OF_MEMORY;
+            }
+            data = janet_unmarshal_u32s(st, data, def->closure_bitset, (def->slotcount + 31) >> 5);
+        }
+
        /* Validate */
        if (janet_verify(def))
            janet_panic("funcdef has invalid bytecode");
@ -857,7 +914,7 @@ static const uint8_t *unmarshal_one_fiber(
    JanetFiber **out,
    int flags) {

-    /* Initialize a new fiber */
+    /* Initialize a new fiber with gc friendly defaults */
    JanetFiber *fiber = janet_gcalloc(JANET_MEMORY_FIBER, sizeof(JanetFiber));
    fiber->flags = 0;
    fiber->frame = 0;
@ -872,42 +929,41 @@ static const uint8_t *unmarshal_one_fiber(
    /* Push fiber to seen stack */
    janet_v_push(st->lookup, janet_wrap_fiber(fiber));

-    /* Set frame later so fiber can be GCed at anytime if unmarshalling fails */
-    int32_t frame = 0;
-    int32_t stack = 0;
-    int32_t stacktop = 0;
-
    /* Read ints */
-    fiber->flags = readint(st, &data);
-    frame = readint(st, &data);
-    fiber->stackstart = readint(st, &data);
-    fiber->stacktop = readint(st, &data);
-    fiber->maxstack = readint(st, &data);
+    int32_t fiber_flags = readint(st, &data);
+    int32_t frame = readnat(st, &data);
+    int32_t fiber_stackstart = readnat(st, &data);
+    int32_t fiber_stacktop = readnat(st, &data);
+    int32_t fiber_maxstack = readnat(st, &data);
+    JanetTable *fiber_env = NULL;

    /* Check for bad flags and ints */
-    if ((int32_t)(frame + JANET_FRAME_SIZE) > fiber->stackstart ||
-            fiber->stackstart > fiber->stacktop ||
-            fiber->stacktop > fiber->maxstack) {
+    if ((int32_t)(frame + JANET_FRAME_SIZE) > fiber_stackstart ||
+            fiber_stackstart > fiber_stacktop ||
+            fiber_stacktop > fiber_maxstack) {
        janet_panic("fiber has incorrect stack setup");
    }

    /* Allocate stack memory */
-    fiber->capacity = fiber->stacktop + 10;
+    fiber->capacity = fiber_stacktop + 10;
    fiber->data = malloc(sizeof(Janet) * fiber->capacity);
    if (!fiber->data) {
        JANET_OUT_OF_MEMORY;
    }
+    for (int32_t i = 0; i < fiber->capacity; i++) {
+        fiber->data[i] = janet_wrap_nil();
+    }

    /* get frames */
-    stack = frame;
-    stacktop = fiber->stackstart - JANET_FRAME_SIZE;
+    int32_t stack = frame;
+    int32_t stacktop = fiber_stackstart - JANET_FRAME_SIZE;
    while (stack > 0) {
        JanetFunction *func = NULL;
        JanetFuncDef *def = NULL;
        JanetFuncEnv *env = NULL;
        int32_t frameflags = readint(st, &data);
-        int32_t prevframe = readint(st, &data);
-        int32_t pcdiff = readint(st, &data);
+        int32_t prevframe = readnat(st, &data);
+        int32_t pcdiff = readnat(st, &data);

        /* Get frame items */
        Janet *framestack = fiber->data + stack;
@ -923,15 +979,7 @@ static const uint8_t *unmarshal_one_fiber(
        /* Check env */
        if (frameflags & JANET_STACKFRAME_HASENV) {
            frameflags &= ~JANET_STACKFRAME_HASENV;
-            int32_t offset = stack;
-            int32_t length = stacktop - stack;
            data = unmarshal_one_env(st, data, &env, flags + 1);
-            if (env->offset != 0 && env->offset != offset)
-                janet_panic("funcenv offset does not match fiber frame");
-            if (env->length != 0 && env->length != length)
-                janet_panic("funcenv length does not match fiber frame");
-            env->offset = offset;
-            env->length = length;
        }

        /* Error checking */
@ -939,11 +987,11 @@ static const uint8_t *unmarshal_one_fiber(
        if (expected_framesize != stacktop - stack) {
            janet_panic("fiber stackframe size mismatch");
        }
-        if (pcdiff < 0 || pcdiff >= def->bytecode_length) {
+        if (pcdiff >= def->bytecode_length) {
            janet_panic("fiber stackframe has invalid pc");
        }
        if ((int32_t)(prevframe + JANET_FRAME_SIZE) > stack) {
-            janet_panic("fibre stackframe does not align with previous frame");
+            janet_panic("fiber stackframe does not align with previous frame");
        }

        /* Get stack items */
@ -966,25 +1014,32 @@ static const uint8_t *unmarshal_one_fiber(
    }

    /* Check for fiber env */
-    if (fiber->flags & JANET_FIBER_FLAG_HASENV) {
+    if (fiber_flags & JANET_FIBER_FLAG_HASENV) {
        Janet envv;
-        fiber->flags &= ~JANET_FIBER_FLAG_HASENV;
+        fiber_flags &= ~JANET_FIBER_FLAG_HASENV;
        data = unmarshal_one(st, data, &envv, flags + 1);
        janet_asserttype(envv, JANET_TABLE);
-        fiber->env = janet_unwrap_table(envv);
+        fiber_env = janet_unwrap_table(envv);
    }

    /* Check for child fiber */
-    if (fiber->flags & JANET_FIBER_FLAG_HASCHILD) {
+    if (fiber_flags & JANET_FIBER_FLAG_HASCHILD) {
        Janet fiberv;
-        fiber->flags &= ~JANET_FIBER_FLAG_HASCHILD;
+        fiber_flags &= ~JANET_FIBER_FLAG_HASCHILD;
        data = unmarshal_one(st, data, &fiberv, flags + 1);
        janet_asserttype(fiberv, JANET_FIBER);
        fiber->child = janet_unwrap_fiber(fiberv);
    }

-    /* Return data */
+    /* We have valid fiber, finally construct remaining fields. */
    fiber->frame = frame;
+    fiber->flags = fiber_flags;
+    fiber->stackstart = fiber_stackstart;
+    fiber->stacktop = fiber_stacktop;
+    fiber->maxstack = fiber_maxstack;
+    fiber->env = fiber_env;
+
+    /* Return data */
    *out = fiber;
    return data;
 }
@ -1043,7 +1098,7 @@ static const uint8_t *unmarshal_one_abstract(UnmarshalState *st, const uint8_t *
    Janet key;
    data = unmarshal_one(st, data, &key, flags + 1);
    const JanetAbstractType *at = janet_get_abstract_type(key);
-    if (at == NULL) return NULL;
+    if (at == NULL) goto oops;
    if (at->unmarshal) {
        JanetMarshalContext context = {NULL, st, flags, data, at};
        *out = janet_wrap_abstract(at->unmarshal(&context));
@ -1052,7 +1107,8 @@ static const uint8_t *unmarshal_one_abstract(UnmarshalState *st, const uint8_t *
        }
        return context.data;
    }
-    return NULL;
+oops:
+    janet_panic("invalid abstract type");
 }

 static const uint8_t *unmarshal_one(
@ -1064,7 +1120,7 @@ static const uint8_t *unmarshal_one(
    MARSH_STACKCHECK;
    MARSH_EOS(st, data);
    lead = data[0];
-    if (lead < 200) {
+    if (lead < LB_REAL) {
        *out = janet_wrap_integer(readint(st, &data));
        return data;
    }
@ -1100,7 +1156,7 @@ static const uint8_t *unmarshal_one(
            u.bytes[0] = data[8];
            u.bytes[1] = data[7];
            u.bytes[2] = data[6];
-            u.bytes[5] = data[5];
+            u.bytes[3] = data[5];
            u.bytes[4] = data[4];
            u.bytes[5] = data[3];
            u.bytes[6] = data[2];
@ -1118,7 +1174,7 @@ static const uint8_t *unmarshal_one(
        case LB_KEYWORD:
        case LB_REGISTRY: {
            data++;
-            int32_t len = readint(st, &data);
+            int32_t len = readnat(st, &data);
            MARSH_EOS(st, data - 1 + len);
            if (lead == LB_STRING) {
                const uint8_t *str = janet_string(data, len);
@ -1178,7 +1234,11 @@ static const uint8_t *unmarshal_one(
            /* Things that open with integers */
        {
            data++;
-            int32_t len = readint(st, &data);
+            int32_t len = readnat(st, &data);
+            /* DOS check */
+            if (lead != LB_REFERENCE) {
+                MARSH_EOS(st, data - 1 + len);
+            }
            if (lead == LB_ARRAY) {
                /* Array */
                JanetArray *array = janet_array(len);
@ -1210,7 +1270,7 @@ static const uint8_t *unmarshal_one(
                *out = janet_wrap_struct(janet_struct_end(struct_));
                janet_v_push(st->lookup, *out);
            } else if (lead == LB_REFERENCE) {
-                if (len < 0 || len >= janet_v_count(st->lookup))
+                if (len >= janet_v_count(st->lookup))
                    janet_panicf("invalid reference %d", len);
                *out = st->lookup[len];
            } else {
--- a/src/core/math.c
+++ b/src/core/math.c
@ -52,7 +52,7 @@ static void *janet_rng_unmarshal(JanetMarshalContext *ctx) {
    return rng;
 }

-static JanetAbstractType JanetRNG_type = {
+const JanetAbstractType janet_rng_type = {
    "core/rng",
    NULL,
    NULL,
@ -115,7 +115,7 @@ double janet_rng_double(JanetRNG *rng) {

 static Janet cfun_rng_make(int32_t argc, Janet *argv) {
    janet_arity(argc, 0, 1);
-    JanetRNG *rng = janet_abstract(&JanetRNG_type, sizeof(JanetRNG));
+    JanetRNG *rng = janet_abstract(&janet_rng_type, sizeof(JanetRNG));
    if (argc == 1) {
        if (janet_checkint(argv[0])) {
            uint32_t seed = (uint32_t)(janet_getinteger(argv, 0));
@ -132,13 +132,13 @@ static Janet cfun_rng_make(int32_t argc, Janet *argv) {

 static Janet cfun_rng_uniform(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetRNG *rng = janet_getabstract(argv, 0, &JanetRNG_type);
+    JanetRNG *rng = janet_getabstract(argv, 0, &janet_rng_type);
    return janet_wrap_number(janet_rng_double(rng));
 }

 static Janet cfun_rng_int(int32_t argc, Janet *argv) {
    janet_arity(argc, 1, 2);
-    JanetRNG *rng = janet_getabstract(argv, 0, &JanetRNG_type);
+    JanetRNG *rng = janet_getabstract(argv, 0, &janet_rng_type);
    if (argc == 1) {
        uint32_t word = janet_rng_u32(rng) >> 1;
        return janet_wrap_integer(word);
@ -166,7 +166,7 @@ static void rng_get_4bytes(JanetRNG *rng, uint8_t *buf) {

 static Janet cfun_rng_buffer(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, 3);
-    JanetRNG *rng = janet_getabstract(argv, 0, &JanetRNG_type);
+    JanetRNG *rng = janet_getabstract(argv, 0, &janet_rng_type);
    int32_t n = janet_getnat(argv, 1);
    JanetBuffer *buffer = janet_optbuffer(argv, argc, 2, n);

@ -255,6 +255,10 @@ JANET_DEFINE_MATHOP(fabs, fabs)
 JANET_DEFINE_MATHOP(floor, floor)
 JANET_DEFINE_MATHOP(trunc, trunc)
 JANET_DEFINE_MATHOP(round, round)
+JANET_DEFINE_MATHOP(gamma, lgamma)
+JANET_DEFINE_MATHOP(log1p, log1p)
+JANET_DEFINE_MATHOP(erf, erf)
+JANET_DEFINE_MATHOP(erfc, erfc)

 #define JANET_DEFINE_MATH2OP(name, fop)\
 static Janet janet_##name(int32_t argc, Janet *argv) {\
@ -267,6 +271,7 @@ static Janet janet_##name(int32_t argc, Janet *argv) {\
 JANET_DEFINE_MATH2OP(atan2, atan2)
 JANET_DEFINE_MATH2OP(pow, pow)
 JANET_DEFINE_MATH2OP(hypot, hypot)
+JANET_DEFINE_MATH2OP(nextafter, nextafter)

 static Janet janet_not(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
@ -438,6 +443,26 @@ static const JanetReg math_cfuns[] = {
        JDOC("(math/exp2 x)\n\n"
             "Returns 2 to the power of x.")
    },
+    {
+        "math/log1p", janet_log1p,
+        JDOC("(math/log1p x)\n\n"
+             "Returns (log base e of x) + 1 more accurately than (+ (math/log x) 1)")
+    },
+    {
+        "math/gamma", janet_gamma,
+        JDOC("(math/gamma x)\n\n"
+             "Returns gamma(x).")
+    },
+    {
+        "math/erfc", janet_erfc,
+        JDOC("(math/erfc x)\n\n"
+             "Returns the complementary error function of x.")
+    },
+    {
+        "math/erf", janet_erf,
+        JDOC("(math/erf x)\n\n"
+             "Returns the error function of x.")
+    },
    {
        "math/expm1", janet_expm1,
        JDOC("(math/expm1 x)\n\n"
@ -453,13 +478,18 @@ static const JanetReg math_cfuns[] = {
        JDOC("(math/round x)\n\n"
             "Returns the integer nearest to x.")
    },
+    {
+        "math/next", janet_nextafter,
+        JDOC("(math/next y)\n\n"
+             "Returns the next representable floating point value after x in the direction of y.")
+    },
    {NULL, NULL, NULL}
 };

 /* Module entry point */
 void janet_lib_math(JanetTable *env) {
    janet_core_cfuns(env, NULL, math_cfuns);
-    janet_register_abstract_type(&JanetRNG_type);
+    janet_register_abstract_type(&janet_rng_type);
 #ifdef JANET_BOOTSTRAP
    janet_def(env, "math/pi", janet_wrap_number(3.1415926535897931),
              JDOC("The value pi."));
--- a/src/core/os.c
+++ b/src/core/os.c
@ -32,6 +32,7 @@
 #include <time.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
@ -69,6 +70,13 @@ extern char **environ;
 void arc4random_buf(void *buf, size_t nbytes);
 #endif

+/* Not POSIX, but all Unixes but Solaris have this function. */
+#if defined(JANET_POSIX) && !defined(__sun)
+time_t timegm(struct tm *tm);
+#elif defined(JANET_WINDOWS)
+#define timegm _mkgmtime
+#endif
+
 /* Access to some global variables should be synchronized if not in single threaded mode, as
 * setenv/getenv are not thread safe. */
 #ifdef JANET_THREADS
@ -401,7 +409,16 @@ static Janet os_execute(int32_t argc, Janet *argv) {
    }

    os_execute_cleanup(envp, child_argv);
-    return janet_wrap_integer(WEXITSTATUS(status));
+    /* Use POSIX shell semantics for interpreting signals */
+    int ret;
+    if (WIFEXITED(status)) {
+        ret = WEXITSTATUS(status);
+    } else if (WIFSTOPPED(status)) {
+        ret = WSTOPSIG(status) + 128;
+    } else {
+        ret = WTERMSIG(status) + 128;
+    }
+    return janet_wrap_integer(ret);
 #endif
 }

@ -621,13 +638,11 @@ static Janet os_date(int32_t argc, Janet *argv) {
    struct tm *t_info = NULL;
    if (argc) {
        int64_t integer = janet_getinteger64(argv, 0);
-        if (integer < 0)
-            janet_panicf("expected non-negative 64 bit signed integer, got %v", argv[0]);
        t = (time_t) integer;
    } else {
        time(&t);
    }
-    if (argc >= 2 && janet_truthy(argv[2])) {
+    if (argc >= 2 && janet_truthy(argv[1])) {
        /* local time */
 #ifdef JANET_WINDOWS
        localtime_s(&t_infos, &t);
@ -658,6 +673,101 @@ static Janet os_date(int32_t argc, Janet *argv) {
    return janet_wrap_struct(janet_struct_end(st));
 }

+static int entry_getdst(Janet env_entry) {
+    Janet v;
+    if (janet_checktype(env_entry, JANET_TABLE)) {
+        JanetTable *entry = janet_unwrap_table(env_entry);
+        v = janet_table_get(entry, janet_ckeywordv("dst"));
+    } else if (janet_checktype(env_entry, JANET_STRUCT)) {
+        const JanetKV *entry = janet_unwrap_struct(env_entry);
+        v = janet_struct_get(entry, janet_ckeywordv("dst"));
+    } else {
+        v = janet_wrap_nil();
+    }
+    if (janet_checktype(v, JANET_NIL)) {
+        return -1;
+    } else {
+        return janet_truthy(v);
+    }
+}
+
+#ifdef JANET_WINDOWS
+typedef int32_t timeint_t;
+#else
+typedef int64_t timeint_t;
+#endif
+
+static timeint_t entry_getint(Janet env_entry, char *field) {
+    Janet i;
+    if (janet_checktype(env_entry, JANET_TABLE)) {
+        JanetTable *entry = janet_unwrap_table(env_entry);
+        i = janet_table_get(entry, janet_ckeywordv(field));
+    } else if (janet_checktype(env_entry, JANET_STRUCT)) {
+        const JanetKV *entry = janet_unwrap_struct(env_entry);
+        i = janet_struct_get(entry, janet_ckeywordv(field));
+    } else {
+        return 0;
+    }
+
+    if (janet_checktype(i, JANET_NIL)) {
+        return 0;
+    }
+
+#ifdef JANET_WINDOWS
+    if (!janet_checkint(i)) {
+        janet_panicf("bad slot #%s, expected 32 bit signed integer, got %v",
+                     field, i);
+    }
+#else
+    if (!janet_checkint64(i)) {
+        janet_panicf("bad slot #%s, expected 64 bit signed integer, got %v",
+                     field, i);
+    }
+#endif
+
+    return (timeint_t)janet_unwrap_number(i);
+}
+
+static Janet os_mktime(int32_t argc, Janet *argv) {
+    janet_arity(argc, 1, 2);
+    time_t t;
+    struct tm t_info;
+
+    /* Use memset instead of = {0} to silence paranoid warning in macos */
+    memset(&t_info, 0, sizeof(t_info));
+
+    if (!janet_checktype(argv[0], JANET_TABLE) &&
+            !janet_checktype(argv[0], JANET_STRUCT))
+        janet_panic_type(argv[0], 0, JANET_TFLAG_DICTIONARY);
+
+    t_info.tm_sec = entry_getint(argv[0], "seconds");
+    t_info.tm_min = entry_getint(argv[0], "minutes");
+    t_info.tm_hour = entry_getint(argv[0], "hours");
+    t_info.tm_mday = entry_getint(argv[0], "month-day") + 1;
+    t_info.tm_mon = entry_getint(argv[0], "month");
+    t_info.tm_year = entry_getint(argv[0], "year") - 1900;
+    t_info.tm_isdst = entry_getdst(argv[0]);
+
+    if (argc >= 2 && janet_truthy(argv[1])) {
+        /* local time */
+        t = mktime(&t_info);
+    } else {
+        /* utc time */
+#ifdef __sun
+        janet_panic("os/mktime UTC not supported on Solaris");
+        return janet_wrap_nil();
+#else
+        t = timegm(&t_info);
+#endif
+    }
+
+    if (t == (time_t) -1) {
+        janet_panicf("%s", strerror(errno));
+    }
+
+    return janet_wrap_number((double)t);
+}
+
 static Janet os_link(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, 3);
 #ifdef JANET_WINDOWS
@ -668,9 +778,25 @@ static Janet os_link(int32_t argc, Janet *argv) {
 #else
    const char *oldpath = janet_getcstring(argv, 0);
    const char *newpath = janet_getcstring(argv, 1);
-    int res = ((argc == 3 && janet_getboolean(argv, 2)) ? symlink : link)(oldpath, newpath);
+    int res = ((argc == 3 && janet_truthy(argv[2])) ? symlink : link)(oldpath, newpath);
    if (-1 == res) janet_panicf("%s: %s -> %s", strerror(errno), oldpath, newpath);
-    return janet_wrap_integer(res);
+    return janet_wrap_nil();
+#endif
+}
+
+static Janet os_symlink(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 2);
+#ifdef JANET_WINDOWS
+    (void) argc;
+    (void) argv;
+    janet_panic("os/symlink not supported on Windows");
+    return janet_wrap_nil();
+#else
+    const char *oldpath = janet_getcstring(argv, 0);
+    const char *newpath = janet_getcstring(argv, 1);
+    int res = symlink(oldpath, newpath);
+    if (-1 == res) janet_panicf("%s: %s -> %s", strerror(errno), oldpath, newpath);
+    return janet_wrap_nil();
 #endif
 }

@ -682,7 +808,9 @@ static Janet os_mkdir(int32_t argc, Janet *argv) {
 #else
    int res = mkdir(path, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IXOTH);
 #endif
-    return janet_wrap_boolean(res != -1);
+    if (res == 0) return janet_wrap_true();
+    if (errno == EEXIST) return janet_wrap_false();
+    janet_panicf("%s: %s", strerror(errno), path);
 }

 static Janet os_rmdir(int32_t argc, Janet *argv) {
@ -737,13 +865,42 @@ static Janet os_remove(int32_t argc, Janet *argv) {
    return janet_wrap_nil();
 }

+static Janet os_readlink(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
 #ifdef JANET_WINDOWS
-static const uint8_t *janet_decode_permissions(unsigned short m) {
-    uint8_t flags[9] = {0};
-    flags[0] = flags[3] = flags[6] = (m & S_IREAD) ? 'r' : '-';
-    flags[1] = flags[4] = flags[7] = (m & S_IWRITE) ? 'w' : '-';
-    flags[2] = flags[5] = flags[8] = (m & S_IEXEC) ? 'x' : '-';
-    return janet_string(flags, sizeof(flags));
+    (void) argc;
+    (void) argv;
+    janet_panic("os/readlink not supported on Windows");
+    return janet_wrap_nil();
+#else
+    static char buffer[PATH_MAX];
+    const char *path = janet_getcstring(argv, 0);
+    ssize_t len = readlink(path, buffer, sizeof buffer);
+    if (len < 0 || (size_t)len >= sizeof buffer)
+        janet_panicf("%s: %s", strerror(errno), path);
+    return janet_stringv((const uint8_t *)buffer, len);
+#endif
+}
+
+#ifdef JANET_WINDOWS
+
+typedef struct _stat jstat_t;
+typedef unsigned short jmode_t;
+
+static int32_t janet_perm_to_unix(unsigned short m) {
+    int32_t ret = 0;
+    if (m & S_IEXEC) ret |= 0111;
+    if (m & S_IWRITE) ret |= 0222;
+    if (m & S_IREAD) ret |= 0444;
+    return ret;
+}
+
+static unsigned short janet_perm_from_unix(int32_t x) {
+    unsigned short m = 0;
+    if (x & 111) m |= S_IEXEC;
+    if (x & 222) m |= S_IWRITE;
+    if (x & 444) m |= S_IREAD;
+    return m;
 }

 static const uint8_t *janet_decode_mode(unsigned short m) {
@ -753,19 +910,22 @@ static const uint8_t *janet_decode_mode(unsigned short m) {
    else if (m & _S_IFCHR) str = "character";
    return janet_ckeyword(str);
 }
+
+static int32_t janet_decode_permissions(jmode_t mode) {
+    return (int32_t)(mode & (S_IEXEC | S_IWRITE | S_IREAD));
+}
+
 #else
-static const uint8_t *janet_decode_permissions(mode_t m) {
-    uint8_t flags[9] = {0};
-    flags[0] = (m & S_IRUSR) ? 'r' : '-';
-    flags[1] = (m & S_IWUSR) ? 'w' : '-';
-    flags[2] = (m & S_IXUSR) ? 'x' : '-';
-    flags[3] = (m & S_IRGRP) ? 'r' : '-';
-    flags[4] = (m & S_IWGRP) ? 'w' : '-';
-    flags[5] = (m & S_IXGRP) ? 'x' : '-';
-    flags[6] = (m & S_IROTH) ? 'r' : '-';
-    flags[7] = (m & S_IWOTH) ? 'w' : '-';
-    flags[8] = (m & S_IXOTH) ? 'x' : '-';
-    return janet_string(flags, sizeof(flags));
+
+typedef struct stat jstat_t;
+typedef mode_t jmode_t;
+
+static int32_t janet_perm_to_unix(mode_t m) {
+    return (int32_t) m;
+}
+
+static mode_t janet_perm_from_unix(int32_t x) {
+    return (mode_t) x;
 }

 static const uint8_t *janet_decode_mode(mode_t m) {
@ -779,75 +939,131 @@ static const uint8_t *janet_decode_mode(mode_t m) {
    else if (S_ISCHR(m)) str = "character";
    return janet_ckeyword(str);
 }
+
+static int32_t janet_decode_permissions(jmode_t mode) {
+    return (int32_t)(mode & 0777);
+}
+
 #endif

-/* Can we do this? */
-#ifdef JANET_WINDOWS
-#define stat _stat
-#endif
+static int32_t os_parse_permstring(const uint8_t *perm) {
+    int32_t m = 0;
+    if (perm[0] == 'r') m |= 0400;
+    if (perm[1] == 'w') m |= 0200;
+    if (perm[2] == 'x') m |= 0100;
+    if (perm[3] == 'r') m |= 0040;
+    if (perm[4] == 'w') m |= 0020;
+    if (perm[5] == 'x') m |= 0010;
+    if (perm[6] == 'r') m |= 0004;
+    if (perm[7] == 'w') m |= 0002;
+    if (perm[8] == 'x') m |= 0001;
+    return m;
+}
+
+static Janet os_make_permstring(int32_t permissions) {
+    uint8_t bytes[9] = {0};
+    bytes[0] = (permissions & 0400) ? 'r' : '-';
+    bytes[1] = (permissions & 0200) ? 'w' : '-';
+    bytes[2] = (permissions & 0100) ? 'x' : '-';
+    bytes[3] = (permissions & 0040) ? 'r' : '-';
+    bytes[4] = (permissions & 0020) ? 'w' : '-';
+    bytes[5] = (permissions & 0010) ? 'x' : '-';
+    bytes[6] = (permissions & 0004) ? 'r' : '-';
+    bytes[7] = (permissions & 0002) ? 'w' : '-';
+    bytes[8] = (permissions & 0001) ? 'x' : '-';
+    return janet_stringv(bytes, sizeof(bytes));
+}
+
+static int32_t os_get_unix_mode(const Janet *argv, int32_t n) {
+    int32_t unix_mode;
+    if (janet_checkint(argv[n])) {
+        /* Integer mode */
+        int32_t x = janet_unwrap_integer(argv[n]);
+        if (x < 0 || x > 0777) {
+            janet_panicf("bad slot #%d, expected integer in range [0, 8r777], got %v", n, argv[n]);
+        }
+        unix_mode = x;
+    } else {
+        /* Bytes mode */
+        JanetByteView bytes = janet_getbytes(argv, n);
+        if (bytes.len != 9) {
+            janet_panicf("bad slot #%d: expected byte sequence of length 9, got %v", n, argv[n]);
+        }
+        unix_mode = os_parse_permstring(bytes.bytes);
+    }
+    return unix_mode;
+}
+
+static jmode_t os_getmode(const Janet *argv, int32_t n) {
+    return janet_perm_from_unix(os_get_unix_mode(argv, n));
+}

 /* Getters */
-static Janet os_stat_dev(struct stat *st) {
+static Janet os_stat_dev(jstat_t *st) {
    return janet_wrap_number(st->st_dev);
 }
-static Janet os_stat_inode(struct stat *st) {
+static Janet os_stat_inode(jstat_t *st) {
    return janet_wrap_number(st->st_ino);
 }
-static Janet os_stat_mode(struct stat *st) {
+static Janet os_stat_mode(jstat_t *st) {
    return janet_wrap_keyword(janet_decode_mode(st->st_mode));
 }
-static Janet os_stat_permissions(struct stat *st) {
-    return janet_wrap_string(janet_decode_permissions(st->st_mode));
+static Janet os_stat_int_permissions(jstat_t *st) {
+    return janet_wrap_integer(janet_perm_to_unix(janet_decode_permissions(st->st_mode)));
 }
-static Janet os_stat_uid(struct stat *st) {
+static Janet os_stat_permissions(jstat_t *st) {
+    return os_make_permstring(janet_perm_to_unix(janet_decode_permissions(st->st_mode)));
+}
+static Janet os_stat_uid(jstat_t *st) {
    return janet_wrap_number(st->st_uid);
 }
-static Janet os_stat_gid(struct stat *st) {
+static Janet os_stat_gid(jstat_t *st) {
    return janet_wrap_number(st->st_gid);
 }
-static Janet os_stat_nlink(struct stat *st) {
+static Janet os_stat_nlink(jstat_t *st) {
    return janet_wrap_number(st->st_nlink);
 }
-static Janet os_stat_rdev(struct stat *st) {
+static Janet os_stat_rdev(jstat_t *st) {
    return janet_wrap_number(st->st_rdev);
 }
-static Janet os_stat_size(struct stat *st) {
+static Janet os_stat_size(jstat_t *st) {
    return janet_wrap_number(st->st_size);
 }
-static Janet os_stat_accessed(struct stat *st) {
+static Janet os_stat_accessed(jstat_t *st) {
    return janet_wrap_number((double) st->st_atime);
 }
-static Janet os_stat_modified(struct stat *st) {
+static Janet os_stat_modified(jstat_t *st) {
    return janet_wrap_number((double) st->st_mtime);
 }
-static Janet os_stat_changed(struct stat *st) {
+static Janet os_stat_changed(jstat_t *st) {
    return janet_wrap_number((double) st->st_ctime);
 }
 #ifdef JANET_WINDOWS
-static Janet os_stat_blocks(struct stat *st) {
+static Janet os_stat_blocks(jstat_t *st) {
    return janet_wrap_number(0);
 }
-static Janet os_stat_blocksize(struct stat *st) {
+static Janet os_stat_blocksize(jstat_t *st) {
    return janet_wrap_number(0);
 }
 #else
-static Janet os_stat_blocks(struct stat *st) {
+static Janet os_stat_blocks(jstat_t *st) {
    return janet_wrap_number(st->st_blocks);
 }
-static Janet os_stat_blocksize(struct stat *st) {
+static Janet os_stat_blocksize(jstat_t *st) {
    return janet_wrap_number(st->st_blksize);
 }
 #endif

 struct OsStatGetter {
    const char *name;
-    Janet(*fn)(struct stat *st);
+    Janet(*fn)(jstat_t *st);
 };

 static const struct OsStatGetter os_stat_getters[] = {
    {"dev", os_stat_dev},
    {"inode", os_stat_inode},
    {"mode", os_stat_mode},
+    {"int-permissions", os_stat_int_permissions},
    {"permissions", os_stat_permissions},
    {"uid", os_stat_uid},
    {"gid", os_stat_gid},
@ -862,7 +1078,7 @@ static const struct OsStatGetter os_stat_getters[] = {
    {NULL, NULL}
 };

-static Janet os_stat(int32_t argc, Janet *argv) {
+static Janet os_stat_or_lstat(int do_lstat, int32_t argc, Janet *argv) {
    janet_arity(argc, 1, 2);
    const char *path = janet_getcstring(argv, 0);
    JanetTable *tab = NULL;
@ -880,8 +1096,18 @@ static Janet os_stat(int32_t argc, Janet *argv) {
    }

    /* Build result */
-    struct stat st;
-    int res = stat(path, &st);
+    jstat_t st;
+#ifdef JANET_WINDOWS
+    (void) do_lstat;
+    int res = _stat(path, &st);
+#else
+    int res;
+    if (do_lstat) {
+        res = lstat(path, &st);
+    } else {
+        res = stat(path, &st);
+    }
+#endif
    if (-1 == res) {
        return janet_wrap_nil();
    }
@ -903,6 +1129,37 @@ static Janet os_stat(int32_t argc, Janet *argv) {
    }
 }

+static Janet os_stat(int32_t argc, Janet *argv) {
+    return os_stat_or_lstat(0, argc, argv);
+}
+
+static Janet os_lstat(int32_t argc, Janet *argv) {
+    return os_stat_or_lstat(1, argc, argv);
+}
+
+static Janet os_chmod(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 2);
+    const char *path = janet_getcstring(argv, 0);
+#ifdef JANET_WINDOWS
+    int res = _chmod(path, os_getmode(argv, 1));
+#else
+    int res = chmod(path, os_getmode(argv, 1));
+#endif
+    if (-1 == res) janet_panicf("%s: %s", strerror(errno), path);
+    return janet_wrap_nil();
+}
+
+static Janet os_umask(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    int mask = (int) os_getmode(argv, 0);
+#ifdef JANET_WINDOWS
+    int res = _umask(mask);
+#else
+    int res = umask(mask);
+#endif
+    return janet_wrap_integer(janet_perm_to_unix(res));
+}
+
 static Janet os_dir(int32_t argc, Janet *argv) {
    janet_arity(argc, 1, 2);
    const char *dir = janet_getcstring(argv, 0);
@ -949,6 +1206,31 @@ static Janet os_rename(int32_t argc, Janet *argv) {
    return janet_wrap_nil();
 }

+static Janet os_realpath(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+#ifdef JANET_WINDOWS
+    (void) argv;
+    janet_panic("os/realpath not supported on Windows");
+#else
+    const char *src = janet_getcstring(argv, 0);
+    char *dest = realpath(src, NULL);
+    if (NULL == dest) janet_panicf("%s: %s", strerror(errno), src);
+    Janet ret = janet_cstringv(dest);
+    free(dest);
+    return ret;
+#endif
+}
+
+static Janet os_permission_string(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    return os_make_permstring(os_get_unix_mode(argv, 0));
+}
+
+static Janet os_permission_int(int32_t argc, Janet *argv) {
+    janet_fixarity(argc, 1);
+    return janet_wrap_integer(os_get_unix_mode(argv, 0));
+}
+
 #endif /* JANET_REDUCED_OS */

 static const JanetReg os_cfuns[] = {
@ -1007,7 +1289,8 @@ static const JanetReg os_cfuns[] = {
             " only that information from stat. If the file or directory does not exist, returns nil. The keys are\n\n"
             "\t:dev - the device that the file is on\n"
             "\t:mode - the type of file, one of :file, :directory, :block, :character, :fifo, :socket, :link, or :other\n"
-             "\t:permissions - A unix permission string like \"rwx--x--x\"\n"
+             "\t:int-permissions - A Unix permission integer like 8r744\n"
+             "\t:permissions - A Unix permission string like \"rwxr--r--\"\n"
             "\t:uid - File uid\n"
             "\t:gid - File gid\n"
             "\t:nlink - number of links to file\n"
@ -1019,6 +1302,19 @@ static const JanetReg os_cfuns[] = {
             "\t:changed - timestamp when file last chnaged (permissions changed)\n"
             "\t:modified - timestamp when file last modified (content changed)\n")
    },
+    {
+        "os/lstat", os_lstat,
+        JDOC("(os/lstat path &opt tab|key)\n\n"
+             "Like os/stat, but don't follow symlinks.\n")
+    },
+    {
+        "os/chmod", os_chmod,
+        JDOC("(os/chmod path mode)\n\n"
+             "Change file permissions, where mode is a permission string as returned by "
+             "os/perm-string, or an integer as returned by os/perm-int. "
+             "When mode is an integer, it is interpreted as a Unix permission value, best specified in octal, like "
+             "8r666 or 8r400. Windows will not differentiate between user, group, and other permissions, and thus will combine all of these permissions. Returns nil.")
+    },
    {
        "os/touch", os_touch,
        JDOC("(os/touch path &opt actime modtime)\n\n"
@ -1028,13 +1324,19 @@ static const JanetReg os_cfuns[] = {
    {
        "os/cd", os_cd,
        JDOC("(os/cd path)\n\n"
-             "Change current directory to path. Returns true on success, false on failure.")
+             "Change current directory to path. Returns nil on success, errors on failure.")
+    },
+    {
+        "os/umask", os_umask,
+        JDOC("(os/umask mask)\n\n"
+             "Set a new umask, returns the old umask.")
    },
    {
        "os/mkdir", os_mkdir,
        JDOC("(os/mkdir path)\n\n"
             "Create a new directory. The path will be relative to the current directory if relative, otherwise "
-             "it will be an absolute path.")
+             "it will be an absolute path. Returns true if the directory was created, false if the directory already exists, and "
+             "errors otherwise.")
    },
    {
        "os/rmdir", os_rmdir,
@ -1049,8 +1351,20 @@ static const JanetReg os_cfuns[] = {
    {
        "os/link", os_link,
        JDOC("(os/link oldpath newpath &opt symlink)\n\n"
-             "Create a symlink from oldpath to newpath. The 3 optional paramater "
-             "enables a hard link over a soft link. Does not work on Windows.")
+             "Create a link at newpath that points to oldpath and returns nil. "
+             "Iff symlink is truthy, creates a symlink. "
+             "Iff symlink is falsey or not provided, "
+             "creates a hard link. Does not work on Windows.")
+    },
+    {
+        "os/symlink", os_symlink,
+        JDOC("(os/symlink oldpath newpath)\n\n"
+             "Create a symlink from oldpath to newpath, returning nil. Same as (os/link oldpath newpath true).")
+    },
+    {
+        "os/readlink", os_readlink,
+        JDOC("(os/readlink path)\n\n"
+             "Read the contents of a symbolic link. Does not work on Windows.\n")
    },
    {
        "os/execute", os_execute,
@ -1080,6 +1394,16 @@ static const JanetReg os_cfuns[] = {
             "Get the current time expressed as the number of seconds since "
             "January 1, 1970, the Unix epoch. Returns a real number.")
    },
+    {
+        "os/mktime", os_mktime,
+        JDOC("(os/mktime date-struct &opt local)\n\n"
+             "Get the broken down date-struct time expressed as the number "
+             " of seconds since January 1, 1970, the Unix epoch. "
+             "Returns a real number. "
+             "Date is given in UTC unless local is truthy, in which case the "
+             "date is computed for the local timezone.\n\n"
+             "Inverse function to os/date.")
+    },
    {
        "os/clock", os_clock,
        JDOC("(os/clock)\n\n"
@ -1100,14 +1424,14 @@ static const JanetReg os_cfuns[] = {
    {
        "os/cryptorand", os_cryptorand,
        JDOC("(os/cryptorand n &opt buf)\n\n"
-             "Get or append n bytes of good quality random data provided by the os. Returns a new buffer or buf.")
+             "Get or append n bytes of good quality random data provided by the OS. Returns a new buffer or buf.")
    },
    {
        "os/date", os_date,
        JDOC("(os/date &opt time local)\n\n"
             "Returns the given time as a date struct, or the current time if no time is given. "
             "Returns a struct with following key values. Note that all numbers are 0-indexed. "
-             "Date is given in UTC unless local is truthy, in which case the date is formated for "
+             "Date is given in UTC unless local is truthy, in which case the date is formatted for "
             "the local timezone.\n\n"
             "\t:seconds - number of seconds [0-61]\n"
             "\t:minutes - number of minutes [0-59]\n"
@ -1124,6 +1448,25 @@ static const JanetReg os_cfuns[] = {
        JDOC("(os/rename oldname newname)\n\n"
             "Rename a file on disk to a new path. Returns nil.")
    },
+    {
+        "os/realpath", os_realpath,
+        JDOC("(os/realpath path)\n\n"
+             "Get the absolute path for a given path, following ../, ./, and symlinks. "
+             "Returns an absolute path as a string. Will raise an error on Windows.")
+    },
+    {
+        "os/perm-string", os_permission_string,
+        JDOC("(os/perm-string int)\n\n"
+             "Convert a Unix octal permission value from a permission integer as returned by os/stat "
+             "to a human readable string, that follows the formatting "
+             "of unix tools like ls. Returns the string as a 9 character string of r, w, x and - characters. Does not "
+             "include the file/directory/symlink character as rendered by `ls`.")
+    },
+    {
+        "os/perm-int", os_permission_int,
+        JDOC("(os/perm-int bytes)\n\n"
+             "Parse a 9 character permission string and return an integer that can be used by chmod.")
+    },
 #endif
    {NULL, NULL, NULL}
 };
--- a/src/core/parse.c
+++ b/src/core/parse.c
@ -26,6 +26,9 @@
 #include "util.h"
 #endif

+#define JANET_PARSER_DEAD 0x1
+#define JANET_PARSER_GENERATED_ERROR 0x2
+
 /* Check if a character is whitespace */
 static int is_whitespace(uint8_t c) {
    return c == ' '
@ -201,6 +204,8 @@ static int checkescape(uint8_t c) {
        default:
            return -1;
        case 'x':
+        case 'u':
+        case 'U':
            return 1;
        case 'n':
            return '\n';
@ -228,6 +233,24 @@ static int checkescape(uint8_t c) {
 /* Forward declare */
 static int stringchar(JanetParser *p, JanetParseState *state, uint8_t c);

+static void write_codepoint(JanetParser *p, int32_t codepoint) {
+    if (codepoint <= 0x7F) {
+        push_buf(p, (uint8_t) codepoint);
+    } else if (codepoint <= 0x7FF) {
+        push_buf(p, (uint8_t)((codepoint >>  6) & 0x1F) | 0xC0);
+        push_buf(p, (uint8_t)((codepoint >>  0) & 0x3F) | 0x80);
+    } else if (codepoint <= 0xFFFF) {
+        push_buf(p, (uint8_t)((codepoint >> 12) & 0x0F) | 0xE0);
+        push_buf(p, (uint8_t)((codepoint >>  6) & 0x3F) | 0x80);
+        push_buf(p, (uint8_t)((codepoint >>  0) & 0x3F) | 0x80);
+    } else {
+        push_buf(p, (uint8_t)((codepoint >> 18) & 0x07) | 0xF0);
+        push_buf(p, (uint8_t)((codepoint >> 12) & 0x3F) | 0x80);
+        push_buf(p, (uint8_t)((codepoint >>  6) & 0x3F) | 0x80);
+        push_buf(p, (uint8_t)((codepoint >>  0) & 0x3F) | 0x80);
+    }
+}
+
 static int escapeh(JanetParser *p, JanetParseState *state, uint8_t c) {
    int digit = to_hex(c);
    if (digit < 0) {
@ -237,7 +260,27 @@ static int escapeh(JanetParser *p, JanetParseState *state, uint8_t c) {
    state->argn = (state->argn << 4) + digit;
    state->counter--;
    if (!state->counter) {
-        push_buf(p, (state->argn & 0xFF));
+        push_buf(p, (uint8_t)(state->argn & 0xFF));
+        state->argn = 0;
+        state->consumer = stringchar;
+    }
+    return 1;
+}
+
+static int escapeu(JanetParser *p, JanetParseState *state, uint8_t c) {
+    int digit = to_hex(c);
+    if (digit < 0) {
+        p->error = "invalid hex digit in unicode escape";
+        return 1;
+    }
+    state->argn = (state->argn << 4) + digit;
+    state->counter--;
+    if (!state->counter) {
+        if (state->argn > 0x10FFFF) {
+            p->error = "invalid unicode codepoint";
+            return 1;
+        }
+        write_codepoint(p, state->argn);
        state->argn = 0;
        state->consumer = stringchar;
    }
@ -254,6 +297,10 @@ static int escape1(JanetParser *p, JanetParseState *state, uint8_t c) {
        state->counter = 2;
        state->argn = 0;
        state->consumer = escapeh;
+    } else if (c == 'u' || c == 'U') {
+        state->counter = c == 'u' ? 4 : 6;
+        state->argn = 0;
+        state->consumer = escapeu;
    } else {
        push_buf(p, (uint8_t) e);
        state->consumer = stringchar;
@ -393,21 +440,23 @@ static Janet close_array(JanetParser *p, JanetParseState *state) {

 static Janet close_struct(JanetParser *p, JanetParseState *state) {
    JanetKV *st = janet_struct_begin(state->argn >> 1);
-    for (int32_t i = state->argn; i > 0; i -= 2) {
-        Janet value = p->args[--p->argcount];
-        Janet key = p->args[--p->argcount];
+    for (size_t i = p->argcount - state->argn; i < p->argcount; i += 2) {
+        Janet key = p->args[i];
+        Janet value = p->args[i + 1];
        janet_struct_put(st, key, value);
    }
+    p->argcount -= state->argn;
    return janet_wrap_struct(janet_struct_end(st));
 }

 static Janet close_table(JanetParser *p, JanetParseState *state) {
    JanetTable *table = janet_table(state->argn >> 1);
-    for (int32_t i = state->argn; i > 0; i -= 2) {
-        Janet value = p->args[--p->argcount];
-        Janet key = p->args[--p->argcount];
+    for (size_t i = p->argcount - state->argn; i < p->argcount; i += 2) {
+        Janet key = p->args[i];
+        Janet value = p->args[i + 1];
        janet_table_put(table, key, value);
    }
+    p->argcount -= state->argn;
    return janet_wrap_table(table);
 }

@ -591,11 +640,30 @@ void janet_parser_eof(JanetParser *parser) {
    size_t oldline = parser->line;
    janet_parser_consume(parser, '\n');
    if (parser->statecount > 1) {
-        parser->error = "unexpected end of source";
+        JanetParseState *s = parser->states + (parser->statecount - 1);
+        JanetBuffer *buffer = janet_buffer(40);
+        janet_buffer_push_cstring(buffer, "unexpected end of source, ");
+        if (s->flags & PFLAG_PARENS) {
+            janet_buffer_push_u8(buffer, '(');
+        } else if (s->flags & PFLAG_SQRBRACKETS) {
+            janet_buffer_push_u8(buffer, '[');
+        } else if (s->flags & PFLAG_CURLYBRACKETS) {
+            janet_buffer_push_u8(buffer, '{');
+        } else if (s->flags & PFLAG_STRING) {
+            janet_buffer_push_u8(buffer, '"');
+        } else if (s->flags & PFLAG_LONGSTRING) {
+            int32_t i;
+            for (i = 0; i < s->argn; i++) {
+                janet_buffer_push_u8(buffer, '`');
+            }
+        }
+        janet_formatb(buffer, " opened at line %d, column %d", s->line, s->column);
+        parser->error = (const char *) janet_string(buffer->data, buffer->count);
+        parser->flag |= JANET_PARSER_GENERATED_ERROR;
    }
    parser->line = oldline;
    parser->column = oldcolumn;
-    parser->flag = 1;
+    parser->flag |= JANET_PARSER_DEAD;
 }

 enum JanetParserStatus janet_parser_status(JanetParser *parser) {
@ -617,6 +685,7 @@ const char *janet_parser_error(JanetParser *parser) {
    if (status == JANET_PARSE_ERROR) {
        const char *e = parser->error;
        parser->error = NULL;
+        parser->flag &= ~JANET_PARSER_GENERATED_ERROR;
        janet_parser_flush(parser);
        return e;
    }
@ -720,6 +789,9 @@ static int parsermark(void *p, size_t size) {
    for (i = 0; i < parser->argcount; i++) {
        janet_mark(parser->args[i]);
    }
+    if (parser->flag & JANET_PARSER_GENERATED_ERROR) {
+        janet_mark(janet_wrap_string(parser->error));
+    }
    return 0;
 }

@ -732,7 +804,7 @@ static int parsergc(void *p, size_t size) {

 static int parserget(void *p, Janet key, Janet *out);

-static JanetAbstractType janet_parse_parsertype = {
+const JanetAbstractType janet_parser_type = {
    "core/parser",
    parsergc,
    parsermark,
@ -744,14 +816,14 @@ static JanetAbstractType janet_parse_parsertype = {
 static Janet cfun_parse_parser(int32_t argc, Janet *argv) {
    (void) argv;
    janet_fixarity(argc, 0);
-    JanetParser *p = janet_abstract(&janet_parse_parsertype, sizeof(JanetParser));
+    JanetParser *p = janet_abstract(&janet_parser_type, sizeof(JanetParser));
    janet_parser_init(p);
    return janet_wrap_abstract(p);
 }

 static Janet cfun_parse_consume(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, 3);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    JanetByteView view = janet_getbytes(argv, 1);
    if (argc == 3) {
        int32_t offset = janet_getinteger(argv, 2);
@ -776,14 +848,14 @@ static Janet cfun_parse_consume(int32_t argc, Janet *argv) {

 static Janet cfun_parse_eof(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    janet_parser_eof(p);
    return argv[0];
 }

 static Janet cfun_parse_insert(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 2);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    JanetParseState *s = p->states + p->statecount - 1;
    if (s->consumer == tokenchar) {
        janet_parser_consume(p, ' ');
@ -817,13 +889,13 @@ static Janet cfun_parse_insert(int32_t argc, Janet *argv) {

 static Janet cfun_parse_has_more(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    return janet_wrap_boolean(janet_parser_has_more(p));
 }

 static Janet cfun_parse_byte(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 2);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    int32_t i = janet_getinteger(argv, 1);
    janet_parser_consume(p, 0xFF & i);
    return argv[0];
@ -831,7 +903,7 @@ static Janet cfun_parse_byte(int32_t argc, Janet *argv) {

 static Janet cfun_parse_status(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    const char *stat = NULL;
    switch (janet_parser_status(p)) {
        case JANET_PARSE_PENDING:
@ -852,28 +924,32 @@ static Janet cfun_parse_status(int32_t argc, Janet *argv) {

 static Janet cfun_parse_error(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    const char *err = janet_parser_error(p);
-    if (err) return janet_cstringv(err);
+    if (err) {
+        return (p->flag & JANET_PARSER_GENERATED_ERROR)
+               ? janet_wrap_string(err)
+               : janet_cstringv(err);
+    }
    return janet_wrap_nil();
 }

 static Janet cfun_parse_produce(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    return janet_parser_produce(p);
 }

 static Janet cfun_parse_flush(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    janet_parser_flush(p);
    return argv[0];
 }

 static Janet cfun_parse_where(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    Janet *tup = janet_tuple_begin(2);
    tup[0] = janet_wrap_integer(p->line);
    tup[1] = janet_wrap_integer(p->column);
@ -953,31 +1029,30 @@ struct ParserStateGetter {
 };

 static Janet parser_state_delimiters(const JanetParser *_p) {
-    JanetParser *clone = janet_abstract(&janet_parse_parsertype, sizeof(JanetParser));
-    janet_parser_clone(_p, clone);
+    JanetParser *p = (JanetParser *)_p;
    size_t i;
    const uint8_t *str;
    size_t oldcount;
-    oldcount = clone->bufcount;
-    for (i = 0; i < clone->statecount; i++) {
-        JanetParseState *s = clone->states + i;
+    oldcount = p->bufcount;
+    for (i = 0; i < p->statecount; i++) {
+        JanetParseState *s = p->states + i;
        if (s->flags & PFLAG_PARENS) {
-            push_buf(clone, '(');
+            push_buf(p, '(');
        } else if (s->flags & PFLAG_SQRBRACKETS) {
-            push_buf(clone, '[');
+            push_buf(p, '[');
        } else if (s->flags & PFLAG_CURLYBRACKETS) {
-            push_buf(clone, '{');
+            push_buf(p, '{');
        } else if (s->flags & PFLAG_STRING) {
-            push_buf(clone, '"');
+            push_buf(p, '"');
        } else if (s->flags & PFLAG_LONGSTRING) {
            int32_t i;
            for (i = 0; i < s->argn; i++) {
-                push_buf(clone, '`');
+                push_buf(p, '`');
            }
        }
    }
-    str = janet_string(clone->buf + oldcount, (int32_t)(clone->bufcount - oldcount));
-    clone->bufcount = oldcount;
+    str = janet_string(p->buf + oldcount, (int32_t)(p->bufcount - oldcount));
+    p->bufcount = oldcount;
    return janet_wrap_string(str);
 }

@ -1004,7 +1079,7 @@ static const struct ParserStateGetter parser_state_getters[] = {
 static Janet cfun_parse_state(int32_t argc, Janet *argv) {
    janet_arity(argc, 1, 2);
    const uint8_t *key = NULL;
-    JanetParser *p = janet_getabstract(argv, 0, &janet_parse_parsertype);
+    JanetParser *p = janet_getabstract(argv, 0, &janet_parser_type);
    if (argc == 2) {
        key = janet_getkeyword(argv, 1);
    }
@ -1031,8 +1106,8 @@ static Janet cfun_parse_state(int32_t argc, Janet *argv) {

 static Janet cfun_parse_clone(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    JanetParser *src = janet_getabstract(argv, 0, &janet_parse_parsertype);
-    JanetParser *dest = janet_abstract(&janet_parse_parsertype, sizeof(JanetParser));
+    JanetParser *src = janet_getabstract(argv, 0, &janet_parser_type);
+    JanetParser *dest = janet_abstract(&janet_parser_type, sizeof(JanetParser));
    janet_parser_clone(src, dest);
    return janet_wrap_abstract(dest);
 }
--- a/src/core/peg.c
+++ b/src/core/peg.c
@ -35,34 +35,6 @@
 * Runtime
 */

-/* opcodes for peg vm */
-typedef enum {
-    RULE_LITERAL,      /* [len, bytes...] */
-    RULE_NCHAR,        /* [n] */
-    RULE_NOTNCHAR,     /* [n] */
-    RULE_RANGE,        /* [lo | hi << 16 (1 word)] */
-    RULE_SET,          /* [bitmap (8 words)] */
-    RULE_LOOK,         /* [offset, rule] */
-    RULE_CHOICE,       /* [len, rules...] */
-    RULE_SEQUENCE,     /* [len, rules...] */
-    RULE_IF,           /* [rule_a, rule_b (b if a)] */
-    RULE_IFNOT,        /* [rule_a, rule_b (b if not a)] */
-    RULE_NOT,          /* [rule] */
-    RULE_BETWEEN,      /* [lo, hi, rule] */
-    RULE_GETTAG,       /* [searchtag, tag] */
-    RULE_CAPTURE,      /* [rule, tag] */
-    RULE_POSITION,     /* [tag] */
-    RULE_ARGUMENT,     /* [argument-index, tag] */
-    RULE_CONSTANT,     /* [constant, tag] */
-    RULE_ACCUMULATE,   /* [rule, tag] */
-    RULE_GROUP,        /* [rule, tag] */
-    RULE_REPLACE,      /* [rule, constant, tag] */
-    RULE_MATCHTIME,    /* [rule, constant, tag] */
-    RULE_ERROR,        /* [rule] */
-    RULE_DROP,         /* [rule] */
-    RULE_BACKMATCH,    /* [tag] */
-} Opcode;
-
 /* Hold captured patterns and match state */
 typedef struct {
    const uint8_t *text_start;
@ -1016,16 +988,9 @@ static uint32_t peg_compile1(Builder *b, Janet peg) {
 * Post-Compilation
 */

-typedef struct {
-    uint32_t *bytecode;
-    Janet *constants;
-    size_t bytecode_len;
-    uint32_t num_constants;
-} Peg;
-
 static int peg_mark(void *p, size_t size) {
    (void) size;
-    Peg *peg = (Peg *)p;
+    JanetPeg *peg = (JanetPeg *)p;
    if (NULL != peg->constants)
        for (uint32_t i = 0; i < peg->num_constants; i++)
            janet_mark(peg->constants[i]);
@ -1033,7 +998,7 @@ static int peg_mark(void *p, size_t size) {
 }

 static void peg_marshal(void *p, JanetMarshalContext *ctx) {
-    Peg *peg = (Peg *)p;
+    JanetPeg *peg = (JanetPeg *)p;
    janet_marshal_size(ctx, peg->bytecode_len);
    janet_marshal_int(ctx, (int32_t)peg->num_constants);
    janet_marshal_abstract(ctx, p);
@ -1055,7 +1020,7 @@ static void *peg_unmarshal(JanetMarshalContext *ctx) {
    uint32_t num_constants = (uint32_t) janet_unmarshal_int(ctx);

    /* Calculate offsets. Should match those in make_peg */
-    size_t bytecode_start = size_padded(sizeof(Peg), sizeof(uint32_t));
+    size_t bytecode_start = size_padded(sizeof(JanetPeg), sizeof(uint32_t));
    size_t bytecode_size = bytecode_len * sizeof(uint32_t);
    size_t constants_start = size_padded(bytecode_start + bytecode_size, sizeof(Janet));
    size_t total_size = constants_start + sizeof(Janet) * (size_t) num_constants;
@ -1065,7 +1030,7 @@ static void *peg_unmarshal(JanetMarshalContext *ctx) {

    /* Allocate PEG */
    char *mem = janet_unmarshal_abstract(ctx, total_size);
-    Peg *peg = (Peg *)mem;
+    JanetPeg *peg = (JanetPeg *)mem;
    uint32_t *bytecode = (uint32_t *)(mem + bytecode_start);
    Janet *constants = (Janet *)(mem + constants_start);
    peg->bytecode = NULL;
@ -1208,7 +1173,7 @@ bad:

 static int cfun_peg_getter(JanetAbstract a, Janet key, Janet *out);

-static const JanetAbstractType peg_type = {
+const JanetAbstractType janet_peg_type = {
    "core/peg",
    NULL,
    peg_mark,
@ -1219,15 +1184,15 @@ static const JanetAbstractType peg_type = {
    JANET_ATEND_UNMARSHAL
 };

-/* Convert Builder to Peg (Janet Abstract Value) */
-static Peg *make_peg(Builder *b) {
-    size_t bytecode_start = size_padded(sizeof(Peg), sizeof(uint32_t));
+/* Convert Builder to JanetPeg (Janet Abstract Value) */
+static JanetPeg *make_peg(Builder *b) {
+    size_t bytecode_start = size_padded(sizeof(JanetPeg), sizeof(uint32_t));
    size_t bytecode_size = janet_v_count(b->bytecode) * sizeof(uint32_t);
    size_t constants_start = size_padded(bytecode_start + bytecode_size, sizeof(Janet));
    size_t constants_size = janet_v_count(b->constants) * sizeof(Janet);
    size_t total_size = constants_start + constants_size;
-    char *mem = janet_abstract(&peg_type, total_size);
-    Peg *peg = (Peg *)mem;
+    char *mem = janet_abstract(&janet_peg_type, total_size);
+    JanetPeg *peg = (JanetPeg *)mem;
    peg->bytecode = (uint32_t *)(mem + bytecode_start);
    peg->constants = (Janet *)(mem + constants_start);
    peg->num_constants = janet_v_count(b->constants);
@ -1238,7 +1203,7 @@ static Peg *make_peg(Builder *b) {
 }

 /* Compiler entry point */
-static Peg *compile_peg(Janet x) {
+static JanetPeg *compile_peg(Janet x) {
    Builder builder;
    builder.grammar = janet_table(0);
    builder.default_grammar = janet_get_core_table("default-peg-grammar");
@ -1249,7 +1214,7 @@ static Peg *compile_peg(Janet x) {
    builder.form = x;
    builder.depth = JANET_RECURSION_GUARD;
    peg_compile1(&builder, x);
-    Peg *peg = make_peg(&builder);
+    JanetPeg *peg = make_peg(&builder);
    builder_cleanup(&builder);
    return peg;
 }
@ -1260,15 +1225,15 @@ static Peg *compile_peg(Janet x) {

 static Janet cfun_peg_compile(int32_t argc, Janet *argv) {
    janet_fixarity(argc, 1);
-    Peg *peg = compile_peg(argv[0]);
+    JanetPeg *peg = compile_peg(argv[0]);
    return janet_wrap_abstract(peg);
 }

 static Janet cfun_peg_match(int32_t argc, Janet *argv) {
    janet_arity(argc, 2, -1);
-    Peg *peg;
+    JanetPeg *peg;
    if (janet_checktype(argv[0], JANET_ABSTRACT) &&
-            janet_abstract_type(janet_unwrap_abstract(argv[0])) == &peg_type) {
+            janet_abstract_type(janet_unwrap_abstract(argv[0])) == &janet_peg_type) {
        peg = janet_unwrap_abstract(argv[0]);
    } else {
        peg = compile_peg(argv[0]);
@ -1327,7 +1292,7 @@ static const JanetReg peg_cfuns[] = {
 /* Load the peg module */
 void janet_lib_peg(JanetTable *env) {
    janet_core_cfuns(env, NULL, peg_cfuns);
-    janet_register_abstract_type(&peg_type);
+    janet_register_abstract_type(&janet_peg_type);
 }

 #endif /* ifdef JANET_PEG */
--- a/src/core/pp.c
+++ b/src/core/pp.c
@ -156,7 +156,7 @@ static void janet_escape_string_impl(JanetBuffer *buffer, const uint8_t *str, in
                janet_buffer_push_bytes(buffer, (const uint8_t *)"\\\\", 2);
                break;
            default:
-                if (c < 32 || c > 127) {
+                if (c < 32 || c > 126) {
                    uint8_t buf[4];
                    buf[0] = '\\';
                    buf[1] = 'x';
@ -459,8 +459,8 @@ static const char *janet_pretty_colors[] = {

 #define JANET_PRETTY_DICT_ONELINE 4
 #define JANET_PRETTY_IND_ONELINE 10
-#define JANET_PRETTY_DICT_LIMIT 16
-#define JANET_PRETTY_ARRAY_LIMIT 16
+#define JANET_PRETTY_DICT_LIMIT 30
+#define JANET_PRETTY_ARRAY_LIMIT 160

 /* Helper for pretty printing */
 static void janet_pretty_one(struct pretty *S, Janet x, int is_dict_value) {
@ -591,6 +591,11 @@ static void janet_pretty_one(struct pretty *S, Janet x, int is_dict_value) {
                if (is_dict_value && len >= JANET_PRETTY_DICT_ONELINE) print_newline(S, 0);
                for (i = 0; i < cap; i++) {
                    if (!janet_checktype(kvs[i].key, JANET_NIL)) {
+                        if (counter == JANET_PRETTY_DICT_LIMIT) {
+                            print_newline(S, 0);
+                            janet_buffer_push_cstring(S->buffer, "...");
+                            break;
+                        }
                        if (first_kv_pair) {
                            first_kv_pair = 0;
                        } else {
@ -600,11 +605,6 @@ static void janet_pretty_one(struct pretty *S, Janet x, int is_dict_value) {
                        janet_buffer_push_u8(S->buffer, ' ');
                        janet_pretty_one(S, kvs[i].value, 1);
                        counter++;
-                        if (counter == 10) {
-                            print_newline(S, 0);
-                            janet_buffer_push_cstring(S->buffer, "...");
-                            break;
-                        }
                    }
                }
            }
@ -728,7 +728,7 @@ static const char *scanformat(
    return p;
 }

-void janet_formatb(JanetBuffer *b, const char *format, va_list args) {
+void janet_formatbv(JanetBuffer *b, const char *format, va_list args) {
    const char *format_end = format + strlen(format);
    const char *c = format;
    int32_t startlen = b->count;
@ -853,7 +853,7 @@ const uint8_t *janet_formatc(const char *format, ...) {
    va_start(args, format);

    /* Run format */
-    janet_formatb(&buffer, format, args);
+    janet_formatbv(&buffer, format, args);

    /* Iterate length */
    va_end(args);
@ -863,6 +863,14 @@ const uint8_t *janet_formatc(const char *format, ...) {
    return ret;
 }

+JanetBuffer *janet_formatb(JanetBuffer *buffer, const char *format, ...) {
+    va_list args;
+    va_start(args, format);
+    janet_formatbv(buffer, format, args);
+    va_end(args);
+    return buffer;
+}
+
 /* Shared implementation between string/format and
 * buffer/format */
 void janet_buffer_format(
--- a/src/core/state.h
+++ b/src/core/state.h
@ -54,6 +54,10 @@ extern JANET_THREAD_LOCAL Janet *janet_vm_return_reg;
 * along with otherwise bare c function pointers. */
 extern JANET_THREAD_LOCAL JanetTable *janet_vm_registry;

+/* Registry for abstract abstract types that can be marshalled.
+ * We need this to look up the constructors when unmarshalling. */
+extern JANET_THREAD_LOCAL JanetTable *janet_vm_abstract_registry;
+
 /* Immutable value cache */
 extern JANET_THREAD_LOCAL const uint8_t **janet_vm_cache;
 extern JANET_THREAD_LOCAL uint32_t janet_vm_cache_capacity;
--- a/src/core/struct.c
+++ b/src/core/struct.c
@ -123,7 +123,8 @@ void janet_struct_put(JanetKV *st, Janet key, Janet value) {
                dist = otherdist;
                hash = otherhash;
            } else if (status == 0) {
-                /* A key was added to the struct more than once */
+                /* A key was added to the struct more than once - replace old value */
+                kv->value = value;
                return;
            }
        }
--- a/src/core/thread.c
+++ b/src/core/thread.c
@ -409,7 +409,7 @@ int janet_thread_receive(Janet *msg_out, double timeout) {

 static int janet_thread_getter(void *p, Janet key, Janet *out);

-static JanetAbstractType Thread_AT = {
+const JanetAbstractType janet_thread_type = {
    "core/thread",
    thread_gc,
    thread_mark,
@ -418,7 +418,7 @@ static JanetAbstractType Thread_AT = {
 };

 static JanetThread *janet_make_thread(JanetMailbox *mailbox, JanetTable *encode) {
-    JanetThread *thread = janet_abstract(&Thread_AT, sizeof(JanetThread));
+    JanetThread *thread = janet_abstract(&janet_thread_type, sizeof(JanetThread));
    janet_mailbox_ref(mailbox, 1);
    thread->mailbox = mailbox;
    thread->encode = encode;
@ -426,7 +426,7 @@ static JanetThread *janet_make_thread(JanetMailbox *mailbox, JanetTable *encode)
 }

 JanetThread *janet_getthread(const Janet *argv, int32_t n) {
-    return (JanetThread *) janet_getabstract(argv, n, &Thread_AT);
+    return (JanetThread *) janet_getabstract(argv, n, &janet_thread_type);
 }

 /* Runs in new thread */
@ -668,7 +668,7 @@ static const JanetReg threadlib_cfuns[] = {
 /* Module entry point */
 void janet_lib_thread(JanetTable *env) {
    janet_core_cfuns(env, NULL, threadlib_cfuns);
-    janet_register_abstract_type(&Thread_AT);
+    janet_register_abstract_type(&janet_thread_type);
 }

 #endif
--- a/src/core/typedarray.c
+++ b/src/core/typedarray.c
@ -111,7 +111,7 @@ static void *ta_buffer_unmarshal(JanetMarshalContext *ctx) {
    return buf;
 }

-static const JanetAbstractType ta_buffer_type = {
+const JanetAbstractType janet_ta_buffer_type = {
    "ta/buffer",
    ta_buffer_gc,
    NULL,
@ -154,7 +154,7 @@ static void *ta_view_unmarshal(JanetMarshalContext *ctx) {
    offset = janet_unmarshal_size(ctx);
    buffer = janet_unmarshal_janet(ctx);
    if (!janet_checktype(buffer, JANET_ABSTRACT) ||
-            (janet_abstract_type(janet_unwrap_abstract(buffer)) != &ta_buffer_type)) {
+            (janet_abstract_type(janet_unwrap_abstract(buffer)) != &janet_ta_buffer_type)) {
        janet_panicf("expected typed array buffer");
    }
    view->buffer = (JanetTArrayBuffer *)janet_unwrap_abstract(buffer);
@ -275,7 +275,7 @@ static void ta_setter(void *p, Janet key, Janet value) {
    }
 }

-static const JanetAbstractType ta_view_type = {
+const JanetAbstractType janet_ta_view_type = {
    "ta/view",
    NULL,
    ta_mark,
@ -287,7 +287,7 @@ static const JanetAbstractType ta_view_type = {
 };

 JanetTArrayBuffer *janet_tarray_buffer(size_t size) {
-    JanetTArrayBuffer *buf = janet_abstract(&ta_buffer_type, sizeof(JanetTArrayBuffer));
+    JanetTArrayBuffer *buf = janet_abstract(&janet_ta_buffer_type, sizeof(JanetTArrayBuffer));
    ta_buffer_init(buf, size);
    return buf;
 }
@ -299,13 +299,13 @@ JanetTArrayView *janet_tarray_view(
    size_t offset,
    JanetTArrayBuffer *buffer) {

-    JanetTArrayView *view = janet_abstract(&ta_view_type, sizeof(JanetTArrayView));
+    JanetTArrayView *view = janet_abstract(&janet_ta_view_type, sizeof(JanetTArrayView));

    if ((stride < 1) || (size < 1)) janet_panic("stride and size should be > 0");
    size_t buf_size = offset + ta_type_sizes[type] * ((size - 1) * stride + 1);

    if (NULL == buffer) {
-        buffer = janet_abstract(&ta_buffer_type, sizeof(JanetTArrayBuffer));
+        buffer = janet_abstract(&janet_ta_buffer_type, sizeof(JanetTArrayBuffer));
        ta_buffer_init(buffer, buf_size);
    }

@ -325,15 +325,15 @@ JanetTArrayView *janet_tarray_view(
 }

 JanetTArrayBuffer *janet_gettarray_buffer(const Janet *argv, int32_t n) {
-    return janet_getabstract(argv, n, &ta_buffer_type);
+    return janet_getabstract(argv, n, &janet_ta_buffer_type);
 }

 JanetTArrayView *janet_gettarray_any(const Janet *argv, int32_t n) {
-    return janet_getabstract(argv, n, &ta_view_type);
+    return janet_getabstract(argv, n, &janet_ta_view_type);
 }

 JanetTArrayView *janet_gettarray_view(const Janet *argv, int32_t n, JanetTArrayType type) {
-    JanetTArrayView *view = janet_getabstract(argv, n, &ta_view_type);
+    JanetTArrayView *view = janet_getabstract(argv, n, &janet_ta_view_type);
    if (view->type != type) {
        janet_panicf("bad slot #%d, expected typed array of type %s, got %v",
                     n, ta_type_names[type], argv[n]);
@ -359,7 +359,7 @@ static Janet cfun_typed_array_new(int32_t argc, Janet *argv) {
                         4, argv[4]);
        }
        void *p = janet_unwrap_abstract(argv[4]);
-        if (janet_abstract_type(p) == &ta_view_type) {
+        if (janet_abstract_type(p) == &janet_ta_view_type) {
            JanetTArrayView *view = (JanetTArrayView *)p;
            offset = (view->buffer->data - view->as.u8) + offset * ta_type_sizes[view->type];
            stride *= view->stride;
@ -375,7 +375,7 @@ static Janet cfun_typed_array_new(int32_t argc, Janet *argv) {
 static JanetTArrayView *ta_is_view(Janet x) {
    if (!janet_checktype(x, JANET_ABSTRACT)) return NULL;
    void *abst = janet_unwrap_abstract(x);
-    if (janet_abstract_type(abst) != &ta_view_type) return NULL;
+    if (janet_abstract_type(abst) != &janet_ta_view_type) return NULL;
    return (JanetTArrayView *)abst;
 }

@ -396,7 +396,7 @@ static Janet cfun_typed_array_size(int32_t argc, Janet *argv) {
    if ((view = ta_is_view(argv[0]))) {
        return janet_wrap_number((double) view->size);
    }
-    JanetTArrayBuffer *buf = (JanetTArrayBuffer *)janet_getabstract(argv, 0, &ta_buffer_type);
+    JanetTArrayBuffer *buf = (JanetTArrayBuffer *)janet_getabstract(argv, 0, &janet_ta_buffer_type);
    return janet_wrap_number((double) buf->size);
 }

@ -433,7 +433,7 @@ static Janet cfun_typed_array_properties(int32_t argc, Janet *argv) {

 static Janet cfun_typed_array_slice(int32_t argc, Janet *argv) {
    janet_arity(argc, 1, 3);
-    JanetTArrayView *src = janet_getabstract(argv, 0, &ta_view_type);
+    JanetTArrayView *src = janet_getabstract(argv, 0, &janet_ta_view_type);
    JanetRange range;
    int32_t length = (int32_t)src->size;
    if (argc == 1) {
@ -461,9 +461,9 @@ static Janet cfun_typed_array_slice(int32_t argc, Janet *argv) {

 static Janet cfun_typed_array_copy_bytes(int32_t argc, Janet *argv) {
    janet_arity(argc, 4, 5);
-    JanetTArrayView *src = janet_getabstract(argv, 0, &ta_view_type);
+    JanetTArrayView *src = janet_getabstract(argv, 0, &janet_ta_view_type);
    size_t index_src = janet_getsize(argv, 1);
-    JanetTArrayView *dst = janet_getabstract(argv, 2, &ta_view_type);
+    JanetTArrayView *dst = janet_getabstract(argv, 2, &janet_ta_view_type);
    size_t index_dst = janet_getsize(argv, 3);
    size_t count = (argc == 5) ? janet_getsize(argv, 4) : 1;
    size_t src_atom_size = ta_type_sizes[src->type];
@ -488,9 +488,9 @@ static Janet cfun_typed_array_copy_bytes(int32_t argc, Janet *argv) {

 static Janet cfun_typed_array_swap_bytes(int32_t argc, Janet *argv) {
    janet_arity(argc, 4, 5);
-    JanetTArrayView *src = janet_getabstract(argv, 0, &ta_view_type);
+    JanetTArrayView *src = janet_getabstract(argv, 0, &janet_ta_view_type);
    size_t index_src = janet_getsize(argv, 1);
-    JanetTArrayView *dst = janet_getabstract(argv, 2, &ta_view_type);
+    JanetTArrayView *dst = janet_getabstract(argv, 2, &janet_ta_view_type);
    size_t index_dst = janet_getsize(argv, 3);
    size_t count = (argc == 5) ? janet_getsize(argv, 4) : 1;
    size_t src_atom_size = ta_type_sizes[src->type];
@ -574,8 +574,8 @@ static JanetMethod tarray_view_methods[] = {
 /* Module entry point */
 void janet_lib_typed_array(JanetTable *env) {
    janet_core_cfuns(env, NULL, ta_cfuns);
-    janet_register_abstract_type(&ta_buffer_type);
-    janet_register_abstract_type(&ta_view_type);
+    janet_register_abstract_type(&janet_ta_buffer_type);
+    janet_register_abstract_type(&janet_ta_view_type);
 }

 #endif
--- a/src/core/util.c
+++ b/src/core/util.c
@ -380,7 +380,7 @@ void janet_var(JanetTable *env, const char *name, Janet val, const char *doc) {
 }

 /* Load many cfunctions at once */
-void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns) {
+static void _janet_cfuns_prefix(JanetTable *env, const char *regprefix, const JanetReg *cfuns, int defprefix) {
    uint8_t *longname_buffer = NULL;
    size_t prefixlen = 0;
    size_t bufsize = 0;
@ -414,47 +414,46 @@ void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns)
            name = janet_csymbolv(cfuns->name);
        }
        Janet fun = janet_wrap_cfunction(cfuns->cfun);
-        janet_def(env, cfuns->name, fun, cfuns->documentation);
+        if (defprefix) {
+            JanetTable *subt = janet_table(2);
+            janet_table_put(subt, janet_ckeywordv("value"), fun);
+            if (cfuns->documentation)
+                janet_table_put(subt, janet_ckeywordv("doc"), janet_cstringv(cfuns->documentation));
+            janet_table_put(env, name, janet_wrap_table(subt));
+        } else {
+            janet_def(env, cfuns->name, fun, cfuns->documentation);
+        }
        janet_table_put(janet_vm_registry, fun, name);
        cfuns++;
    }
    free(longname_buffer);
 }

+void janet_cfuns_prefix(JanetTable *env, const char *regprefix, const JanetReg *cfuns) {
+    _janet_cfuns_prefix(env, regprefix, cfuns, 1);
+}
+
+void janet_cfuns(JanetTable *env, const char *regprefix, const JanetReg *cfuns) {
+    _janet_cfuns_prefix(env, regprefix, cfuns, 0);
+}
+
 /* Abstract type introspection */

-static const JanetAbstractType type_wrap = {
-    "core/type-info",
-    JANET_ATEND_NAME
-};
-
-typedef struct {
-    const JanetAbstractType *at;
-} JanetAbstractTypeWrap;
-
 void janet_register_abstract_type(const JanetAbstractType *at) {
-    JanetAbstractTypeWrap *abstract = (JanetAbstractTypeWrap *)
-                                      janet_abstract(&type_wrap, sizeof(JanetAbstractTypeWrap));
-    abstract->at = at;
    Janet sym = janet_csymbolv(at->name);
-    if (!(janet_checktype(janet_table_get(janet_vm_registry, sym), JANET_NIL))) {
+    if (!(janet_checktype(janet_table_get(janet_vm_abstract_registry, sym), JANET_NIL))) {
        janet_panicf("cannot register abstract type %s, "
                     "a type with the same name exists", at->name);
    }
-    janet_table_put(janet_vm_registry, sym, janet_wrap_abstract(abstract));
+    janet_table_put(janet_vm_abstract_registry, sym, janet_wrap_pointer((void *) at));
 }

 const JanetAbstractType *janet_get_abstract_type(Janet key) {
-    Janet twrap = janet_table_get(janet_vm_registry, key);
-    if (janet_checktype(twrap, JANET_NIL)) {
+    Janet wrapped = janet_table_get(janet_vm_abstract_registry, key);
+    if (janet_checktype(wrapped, JANET_NIL)) {
        return NULL;
    }
-    if (!janet_checktype(twrap, JANET_ABSTRACT) ||
-            (janet_abstract_type(janet_unwrap_abstract(twrap)) != &type_wrap)) {
-        janet_panic("expected abstract type");
-    }
-    JanetAbstractTypeWrap *w = (JanetAbstractTypeWrap *)janet_unwrap_abstract(twrap);
-    return w->at;
+    return (JanetAbstractType *)(janet_unwrap_pointer(wrapped));
 }

 #ifndef JANET_BOOTSTRAP
--- a/src/core/vm.c
+++ b/src/core/vm.c
@ -35,6 +35,7 @@
 /* VM state */
 JANET_THREAD_LOCAL JanetTable *janet_vm_core_env;
 JANET_THREAD_LOCAL JanetTable *janet_vm_registry;
+JANET_THREAD_LOCAL JanetTable *janet_vm_abstract_registry;
 JANET_THREAD_LOCAL int janet_vm_stackn = 0;
 JANET_THREAD_LOCAL JanetFiber *janet_vm_fiber = NULL;
 JANET_THREAD_LOCAL JanetFiber *janet_vm_root_fiber = NULL;
@ -89,8 +90,8 @@ JANET_THREAD_LOCAL jmp_buf *janet_vm_jmp_buf = NULL;
    func = janet_stack_frame(stack)->func; \
 } while (0)
 #define vm_return(sig, val) do { \
-    vm_commit(); \
    janet_vm_return_reg[0] = (val); \
+    vm_commit(); \
    return (sig); \
 } while (0)

@ -107,13 +108,13 @@ JANET_THREAD_LOCAL jmp_buf *janet_vm_jmp_buf = NULL;
 #define vm_assert_type(X, T) do { \
    if (!(janet_checktype((X), (T)))) { \
        vm_commit(); \
-        janet_panicf("expected %T, got %t", (1 << (T)), (X)); \
+        janet_panicf("expected %T, got %v", (1 << (T)), (X)); \
    } \
 } while (0)
 #define vm_assert_types(X, TS) do { \
    if (!(janet_checktypes((X), (TS)))) { \
        vm_commit(); \
-        janet_panicf("expected %T, got %t", (TS), (X)); \
+        janet_panicf("expected %T, got %v", (TS), (X)); \
    } \
 } while (0)

@ -290,6 +291,10 @@ static Janet janet_binop_call(const char *lmethod, const char *rmethod, Janet lh
    }
 }

+/* Forward declaration */
+static JanetSignal janet_check_can_resume(JanetFiber *fiber, Janet *out);
+static JanetSignal janet_continue_no_check(JanetFiber *fiber, Janet in, Janet *out);
+
 /* Interpreter main loop */
 static JanetSignal run_vm(JanetFiber *fiber, Janet in) {

@ -824,7 +829,8 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
        vm_assert(func->def->environments_length > eindex, "invalid upvalue environment");
        env = func->envs[eindex];
        vm_assert(env->length > vindex, "invalid upvalue index");
-        if (env->offset) {
+        vm_assert(janet_env_valid(env), "invalid upvalue environment");
+        if (env->offset > 0) {
            /* On stack */
            stack[A] = env->as.fiber->data[env->offset + vindex];
        } else {
@ -841,7 +847,8 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
        vm_assert(func->def->environments_length > eindex, "invalid upvalue environment");
        env = func->envs[eindex];
        vm_assert(env->length > vindex, "invalid upvalue index");
-        if (env->offset) {
+        vm_assert(janet_env_valid(env), "invalid upvalue environment");
+        if (env->offset > 0) {
            env->as.fiber->data[env->offset + vindex] = stack[A];
        } else {
            env->as.values[vindex] = stack[A];
@ -904,7 +911,7 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
        if (janet_indexed_view(stack[D], &vals, &len)) {
            janet_fiber_pushn(fiber, vals, len);
        } else {
-            janet_panicf("expected %T, got %t", JANET_TFLAG_INDEXED, stack[D]);
+            janet_panicf("expected %T, got %v", JANET_TFLAG_INDEXED, stack[D]);
        }
    }
    stack = fiber->data + fiber->frame;
@ -997,8 +1004,12 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
        Janet retreg;
        vm_assert_type(stack[B], JANET_FIBER);
        JanetFiber *child = janet_unwrap_fiber(stack[B]);
+        if (janet_check_can_resume(child, &retreg)) {
+            vm_commit();
+            janet_panicv(retreg);
+        }
        fiber->child = child;
-        JanetSignal sig = janet_continue(child, stack[C], &retreg);
+        JanetSignal sig = janet_continue_no_check(child, stack[C], &retreg);
        if (sig != JANET_SIGNAL_OK && !(child->flags & (1 << sig))) {
            vm_return(sig, retreg);
        }
@ -1241,10 +1252,7 @@ Janet janet_call(JanetFunction *fun, int32_t argc, const Janet *argv) {
    return *janet_vm_return_reg;
 }

-/* Enter the main vm loop */
-JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out) {
-    jmp_buf buf;
-
+static JanetSignal janet_check_can_resume(JanetFiber *fiber, Janet *out) {
    /* Check conditions */
    JanetFiberStatus old_status = janet_fiber_status(fiber);
    if (janet_vm_stackn >= JANET_RECURSION_GUARD) {
@ -1261,6 +1269,13 @@ JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out) {
        *out = janet_wrap_string(str);
        return JANET_SIGNAL_ERROR;
    }
+    return JANET_SIGNAL_OK;
+}
+
+static JanetSignal janet_continue_no_check(JanetFiber *fiber, Janet in, Janet *out) {
+    jmp_buf buf;
+
+    JanetFiberStatus old_status = janet_fiber_status(fiber);

    /* Continue child fiber if it exists */
    if (fiber->child) {
@ -1334,6 +1349,14 @@ JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out) {
    return signal;
 }

+/* Enter the main vm loop */
+JanetSignal janet_continue(JanetFiber *fiber, Janet in, Janet *out) {
+    /* Check conditions */
+    JanetSignal tmp_signal = janet_check_can_resume(fiber, out);
+    if (tmp_signal) return tmp_signal;
+    return janet_continue_no_check(fiber, in, out);
+}
+
 JanetSignal janet_pcall(
    JanetFunction *fun,
    int32_t argc,
@ -1387,7 +1410,9 @@ int janet_init(void) {
    janet_scratch_cap = 0;
    /* Initialize registry */
    janet_vm_registry = janet_table(0);
+    janet_vm_abstract_registry = janet_table(0);
    janet_gcroot(janet_wrap_table(janet_vm_registry));
+    janet_gcroot(janet_wrap_table(janet_vm_abstract_registry));
    /* Core env */
    janet_vm_core_env = NULL;
    /* Seed RNG */
@ -1412,6 +1437,7 @@ void janet_deinit(void) {
    janet_vm_root_count = 0;
    janet_vm_root_capacity = 0;
    janet_vm_registry = NULL;
+    janet_vm_abstract_registry = NULL;
    janet_vm_core_env = NULL;
    janet_vm_fiber = NULL;
    janet_vm_root_fiber = NULL;
--- a/src/include/janet.h
+++ b/src/include/janet.h
@ -97,7 +97,14 @@ extern "C" {
 #endif

 /* Check big endian */
-#if defined(__MIPSEB__) /* MIPS 32-bit */ \
+#if defined(__LITTLE_ENDIAN__) || \
+    (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+/* If we know the target is LE, always use that - e.g. ppc64 little endian
+ * defines the __LITTLE_ENDIAN__ macro in the ABI spec, so we can rely
+ * on that and if that's not defined, fall back to big endian assumption
+ */
+#define JANET_LITTLE_ENDIAN 1
+#elif defined(__MIPSEB__) /* MIPS 32-bit */ \
    || defined(__ppc__) || defined(__PPC__) /* CPU(PPC) - PowerPC 32-bit */ \
    || defined(__powerpc__) || defined(__powerpc) || defined(__POWERPC__) \
    || defined(_M_PPC) || defined(__PPC) \
@ -661,7 +668,7 @@ struct Janet {
 #define janet_type(x) ((x).type)
 #define janet_checktype(x, t) ((x).type == (t))
 #define janet_truthy(x) \
-    ((x).type != JANET_NIL && ((x).type != JANET_BOOLEAN || ((x).as.integer & 0x1)))
+    ((x).type != JANET_NIL && ((x).type != JANET_BOOLEAN || ((x).as.u64 & 0x1)))

 #define janet_unwrap_struct(x) ((const JanetKV *)(x).as.pointer)
 #define janet_unwrap_tuple(x) ((const Janet *)(x).as.pointer)
@ -731,8 +738,9 @@ struct JanetStackFrame {
    int32_t flags;
 };

-/* Number of Janets a frame takes up in the stack */
-#define JANET_FRAME_SIZE ((sizeof(JanetStackFrame) + sizeof(Janet) - 1) / sizeof(Janet))
+/* Number of Janets a frame takes up in the stack
+ * Should be constant across architectures */
+#define JANET_FRAME_SIZE 4

 /* A dynamic array type. */
 struct JanetArray {
@ -810,6 +818,7 @@ struct JanetAbstractHead {
 #define JANET_FUNCDEF_FLAG_HASENVS 0x400000
 #define JANET_FUNCDEF_FLAG_HASSOURCEMAP 0x800000
 #define JANET_FUNCDEF_FLAG_STRUCTARG 0x1000000
+#define JANET_FUNCDEF_FLAG_HASCLOBITSET 0x2000000
 #define JANET_FUNCDEF_FLAG_TAG 0xFFFF

 /* Source mapping structure for a bytecode instruction */
@ -825,6 +834,7 @@ struct JanetFuncDef {
    Janet *constants;
    JanetFuncDef **defs;
    uint32_t *bytecode;
+    uint32_t *closure_bitset; /* Bit set indicating which slots can be referenced by closures. */

    /* Various debug information */
    JanetSourceMapping *sourcemap;
@ -892,8 +902,9 @@ struct JanetParser {
    int flag;
 };

+/* A context for marshaling and unmarshaling abstract types */
 typedef struct {
-    void *m_state;  /* void* to not expose MarshalState ?*/
+    void *m_state;
    void *u_state;
    int flags;
    const uint8_t *data;
@ -970,6 +981,12 @@ struct JanetRNG {
    uint32_t counter;
 };

+typedef struct JanetFile JanetFile;
+struct JanetFile {
+    FILE *file;
+    int flags;
+};
+
 /* Thread types */
 #ifdef JANET_THREADS
 typedef struct JanetThread JanetThread;
@ -1105,6 +1122,7 @@ JANET_API void janet_loop(void);
 #endif

 /* Parsing */
+extern JANET_API const JanetAbstractType janet_parser_type;
 JANET_API void janet_parser_init(JanetParser *parser);
 JANET_API void janet_parser_deinit(JanetParser *parser);
 JANET_API void janet_parser_consume(JanetParser *parser, uint8_t c);
@ -1166,6 +1184,7 @@ JANET_API void janet_debug_find(
    JanetString source, int32_t line, int32_t column);

 /* RNG */
+extern JANET_API const JanetAbstractType janet_rng_type;
 JANET_API JanetRNG *janet_default_rng(void);
 JANET_API void janet_rng_seed(JanetRNG *rng, uint32_t seed);
 JANET_API void janet_rng_longseed(JanetRNG *rng, const uint8_t *bytes, int32_t len);
@ -1229,7 +1248,8 @@ JANET_API void janet_description_b(JanetBuffer *buffer, Janet x);
 #define janet_cstringv(cstr) janet_wrap_string(janet_cstring(cstr))
 #define janet_stringv(str, len) janet_wrap_string(janet_string((str), (len)))
 JANET_API JanetString janet_formatc(const char *format, ...);
-JANET_API void janet_formatb(JanetBuffer *bufp, const char *format, va_list args);
+JANET_API JanetBuffer *janet_formatb(JanetBuffer *bufp, const char *format, ...);
+JANET_API void janet_formatbv(JanetBuffer *bufp, const char *format, va_list args);

 /* Symbol functions */
 JANET_API JanetSymbol janet_symbol(const uint8_t *str, int32_t len);
@ -1479,6 +1499,8 @@ JANET_API JanetArray *janet_optarray(const Janet *argv, int32_t argc, int32_t n,
 JANET_API Janet janet_dyn(const char *name);
 JANET_API void janet_setdyn(const char *name, Janet value);

+extern JANET_API const JanetAbstractType janet_file_type;
+
 #define JANET_FILE_WRITE 1
 #define JANET_FILE_READ 2
 #define JANET_FILE_APPEND 4
@ -1516,8 +1538,52 @@ JANET_API JanetAbstract janet_unmarshal_abstract(JanetMarshalContext *ctx, size_
 JANET_API void janet_register_abstract_type(const JanetAbstractType *at);
 JANET_API const JanetAbstractType *janet_get_abstract_type(Janet key);

+#ifdef JANET_PEG
+
+extern JANET_API const JanetAbstractType janet_peg_type;
+
+/* opcodes for peg vm */
+typedef enum {
+    RULE_LITERAL,      /* [len, bytes...] */
+    RULE_NCHAR,        /* [n] */
+    RULE_NOTNCHAR,     /* [n] */
+    RULE_RANGE,        /* [lo | hi << 16 (1 word)] */
+    RULE_SET,          /* [bitmap (8 words)] */
+    RULE_LOOK,         /* [offset, rule] */
+    RULE_CHOICE,       /* [len, rules...] */
+    RULE_SEQUENCE,     /* [len, rules...] */
+    RULE_IF,           /* [rule_a, rule_b (b if a)] */
+    RULE_IFNOT,        /* [rule_a, rule_b (b if not a)] */
+    RULE_NOT,          /* [rule] */
+    RULE_BETWEEN,      /* [lo, hi, rule] */
+    RULE_GETTAG,       /* [searchtag, tag] */
+    RULE_CAPTURE,      /* [rule, tag] */
+    RULE_POSITION,     /* [tag] */
+    RULE_ARGUMENT,     /* [argument-index, tag] */
+    RULE_CONSTANT,     /* [constant, tag] */
+    RULE_ACCUMULATE,   /* [rule, tag] */
+    RULE_GROUP,        /* [rule, tag] */
+    RULE_REPLACE,      /* [rule, constant, tag] */
+    RULE_MATCHTIME,    /* [rule, constant, tag] */
+    RULE_ERROR,        /* [rule] */
+    RULE_DROP,         /* [rule] */
+    RULE_BACKMATCH,    /* [tag] */
+} JanetPegOpcode;
+
+typedef struct {
+    uint32_t *bytecode;
+    Janet *constants;
+    size_t bytecode_len;
+    uint32_t num_constants;
+} JanetPeg;
+
+#endif
+
 #ifdef JANET_TYPED_ARRAY

+extern JANET_API const JanetAbstractType janet_ta_view_type;
+extern JANET_API const JanetAbstractType janet_ta_buffer_type;
+
 typedef enum {
    JANET_TARRAY_TYPE_U8,
    JANET_TARRAY_TYPE_S8,
@ -1568,6 +1634,9 @@ JanetTArrayView *janet_gettarray_any(const Janet *argv, int32_t n);

 #ifdef JANET_INT_TYPES

+extern JANET_API const JanetAbstractType janet_s64_type;
+extern JANET_API const JanetAbstractType janet_u64_type;
+
 typedef enum {
    JANET_INT_NONE,
    JANET_INT_S64,
@ -1584,6 +1653,15 @@ JANET_API int janet_scan_uint64(const uint8_t *str, int32_t len, uint64_t *out);

 #endif

+#ifdef JANET_THREADS
+
+extern JANET_API const JanetAbstractType janet_thread_type;
+
+JANET_API int janet_thread_receive(Janet *msg_out, double timeout);
+JANET_API int janet_thread_send(JanetThread *thread, Janet msg, double timeout);
+
+#endif
+
 /***** END SECTION MAIN *****/

 #ifdef __cplusplus
--- a/src/mainclient/shell.c
+++ b/src/mainclient/shell.c
@ -515,6 +515,147 @@ static void check_specials(JanetByteView src) {
    check_cmatch(src, "while");
 }

+static void resolve_format(JanetTable *entry) {
+    int is_macro = janet_truthy(janet_table_get(entry, janet_ckeywordv("macro")));
+    Janet refv = janet_table_get(entry, janet_ckeywordv("ref"));
+    int is_ref = janet_checktype(refv, JANET_ARRAY);
+    Janet value = janet_wrap_nil();
+    if (is_ref) {
+        JanetArray *a = janet_unwrap_array(refv);
+        if (a->count) value = a->data[0];
+    } else {
+        value = janet_table_get(entry, janet_ckeywordv("value"));
+    }
+    if (is_macro) {
+        fprintf(stderr, "    macro\n");
+        gbl_lines_below++;
+    } else if (is_ref) {
+        janet_eprintf("    var (%t)\n", value);
+        gbl_lines_below++;
+    } else {
+        janet_eprintf("    %t\n", value);
+        gbl_lines_below++;
+    }
+    Janet sm = janet_table_get(entry, janet_ckeywordv("source-map"));
+    Janet path = janet_get(sm, janet_wrap_integer(0));
+    Janet line = janet_get(sm, janet_wrap_integer(1));
+    Janet col = janet_get(sm, janet_wrap_integer(2));
+    if (janet_checktype(path, JANET_STRING) && janet_truthy(line) && janet_truthy(col)) {
+        janet_eprintf("    %S on line %v, column %v\n", janet_unwrap_string(path), line, col);
+        gbl_lines_below++;
+    }
+}
+
+static void doc_format(JanetString doc, int32_t width) {
+    int32_t maxcol = width - 8;
+    uint8_t wordbuf[256] = {0};
+    int32_t wordp = 0;
+    int32_t current = 0;
+    if (maxcol > 200) maxcol = 200;
+    fprintf(stderr, "    ");
+    for (int32_t i = 0; i < janet_string_length(doc); i++) {
+        uint8_t b = doc[i];
+        switch (b) {
+            default: {
+                if (maxcol <= current + wordp + 1) {
+                    if (!current) {
+                        fwrite(wordbuf, wordp, 1, stderr);
+                        wordp = 0;
+                    }
+                    fprintf(stderr, "\n    ");
+                    gbl_lines_below++;
+                    current = 0;
+                }
+                wordbuf[wordp++] = b;
+                break;
+            }
+            case '\t': {
+                if (maxcol <= current + wordp + 2) {
+                    if (!current) {
+                        fwrite(wordbuf, wordp, 1, stderr);
+                        wordp = 0;
+                    }
+                    fprintf(stderr, "\n    ");
+                    gbl_lines_below++;
+                    current = 0;
+                }
+                wordbuf[wordp++] = ' ';
+                wordbuf[wordp++] = ' ';
+                break;
+            }
+            case '\n':
+            case ' ': {
+                if (wordp) {
+                    int32_t oldcur = current;
+                    int spacer = maxcol > current + wordp + 1;
+                    if (spacer) current++;
+                    else current = 0;
+                    current += wordp;
+                    if (oldcur) fprintf(stderr, spacer ? " " : "\n    ");
+                    if (oldcur && !spacer) gbl_lines_below++;
+                    fwrite(wordbuf, wordp, 1, stderr);
+                    wordp = 0;
+                }
+                if (b == '\n') {
+                    fprintf(stderr, "\n    ");
+                    gbl_lines_below++;
+                    current = 0;
+                }
+            }
+        }
+    }
+    if (wordp) {
+        int32_t oldcur = current;
+        int spacer = maxcol > current + wordp + 1;
+        if (spacer) current++;
+        else current = 0;
+        current += wordp + 1;
+        if (oldcur) fprintf(stderr, spacer ? " " : "\n    ");
+        if (oldcur && !spacer) gbl_lines_below++;
+        fwrite(wordbuf, wordp, 1, stderr);
+        wordp = 0;
+    }
+}
+
+static void find_matches(JanetByteView prefix) {
+    JanetTable *env = gbl_complete_env;
+    gbl_match_count = 0;
+    while (NULL != env) {
+        JanetKV *kvend = env->data + env->capacity;
+        for (JanetKV *kv = env->data; kv < kvend; kv++) {
+            if (!janet_checktype(kv->key, JANET_SYMBOL)) continue;
+            const uint8_t *sym = janet_unwrap_symbol(kv->key);
+            check_match(prefix, sym, janet_string_length(sym));
+        }
+        env = env->proto;
+    }
+}
+
+static void kshowdoc(void) {
+    if (!gbl_complete_env) return;
+    while (is_symbol_char_gen(gbl_buf[gbl_pos])) gbl_pos++;
+    JanetByteView prefix = get_symprefix();
+    Janet symbol = janet_symbolv(prefix.bytes, prefix.len);
+    Janet entry = janet_table_get(gbl_complete_env, symbol);
+    if (!janet_checktype(entry, JANET_TABLE)) return;
+    Janet doc = janet_table_get(janet_unwrap_table(entry), janet_ckeywordv("doc"));
+    if (!janet_checktype(doc, JANET_STRING)) return;
+    JanetString docs = janet_unwrap_string(doc);
+    int num_cols = getcols();
+    clearlines();
+    fprintf(stderr, "\n\n\n");
+    gbl_lines_below += 3;
+    resolve_format(janet_unwrap_table(entry));
+    fprintf(stderr, "\n");
+    gbl_lines_below += 1;
+    doc_format(docs, num_cols);
+    fprintf(stderr, "\n\n");
+    gbl_lines_below += 2;
+    /* Go up to original line (zsh-like autocompletion) */
+    fprintf(stderr, "\x1B[%dA", gbl_lines_below);
+    fflush(stderr);
+}
+
 static void kshowcomp(void) {
    JanetTable *env = gbl_complete_env;
    if (env == NULL) {
@ -528,19 +669,9 @@ static void kshowcomp(void) {
        gbl_pos++;

    JanetByteView prefix = get_symprefix();
-    if (prefix.len  == 0) return;
+    if (prefix.len == 0) return;

-    /* Find all matches */
-    gbl_match_count = 0;
-    while (NULL != env) {
-        JanetKV *kvend = env->data + env->capacity;
-        for (JanetKV *kv = env->data; kv < kvend; kv++) {
-            if (!janet_checktype(kv->key, JANET_SYMBOL)) continue;
-            const uint8_t *sym = janet_unwrap_symbol(kv->key);
-            check_match(prefix, sym, janet_string_length(sym));
-        }
-        env = env->proto;
-    }
+    find_matches(prefix);

    check_specials(prefix);

@ -623,7 +754,7 @@ static int line() {
                if (gbl_len == 0) {   /* quit on empty line */
                    clearlines();
                    return -1;
-                } 
+                }
                kdelete(1);
                break;
            case 5:     /* ctrl-e */
@ -633,6 +764,10 @@ static int line() {
            case 6:     /* ctrl-f */
                kright();
                break;
+            case 7: /* ctrl-g */
+                kshowdoc();
+                refresh();
+                break;
            case 127:   /* backspace */
            case 8:     /* ctrl-h */
                kbackspace(1);
--- a/test/fuzzers/fuzz_dostring.c
+++ b/test/fuzzers/fuzz_dostring.c
@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <string.h>
+#include <janet.h>
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    char *new_str = (char *)malloc(size + 1);
+    if (new_str == NULL) {
+        return 0;
+    }
+    memcpy(new_str, data, size);
+    new_str[size] = '\0';
+
+    /* janet logic */
+    janet_init();
+    JanetTable *env = janet_core_env(NULL);
+    janet_dostring(env, new_str, "main", NULL);
+    janet_deinit();
+
+    free(new_str);
+    return 0;
+}
+
--- a/test/helper.janet
+++ b/test/helper.janet
@ -8,7 +8,8 @@

 (defn assert
  "Override's the default assert with some nice error handling."
-  [x e]
+  [x &opt e]
+  (default e "assert error")
  (++ num-tests-run)
  (when x (++ num-tests-passed))
  (if x
--- a/test/suite0.janet
+++ b/test/suite0.janet
@ -206,6 +206,10 @@
 (def 🐮 :cow)
 (assert (= (string "🐼" 🦊 🐮) "🐼foxcow") "emojis 🙉 :)")
 (assert (not= 🦊 "🦊") "utf8 strings are not symbols and vice versa")
+(assert (= "\U01F637" "😷") "unicode escape 1")
+(assert (= "\u2623" "\U002623" "☣") "unicode escape 2")
+(assert (= "\u24c2" "\U0024c2" "Ⓜ") "unicode escape 3")
+(assert (= "\u0061" "a") "unicode escape 4")

 # Symbols with @ character

@ -250,6 +254,11 @@
 (assert (apply <= (merge @[1 3 5] @[2 4 6 6 6 9])) "merge sort merge 3")
 (assert (apply <= (merge '(1 3 5) @[2 4 6 6 6 9])) "merge sort merge 4")

+(assert (deep= @[1 2 3 4 5] (sort @[5 3 4 1 2])) "sort 1")
+(assert (deep= @[{:a 1} {:a 4} {:a 7}] (sort-by |($ :a) @[{:a 4} {:a 7} {:a 1}])) "sort 2")
+(assert (deep= @[1 2 3 4 5] (sorted [5 3 4 1 2])) "sort 3")
+(assert (deep= @[{:a 1} {:a 4} {:a 7}] (sorted-by |($ :a) [{:a 4} {:a 7} {:a 1}])) "sort 4")
+
 # Gensym tests

 (assert (not= (gensym) (gensym)) "two gensyms not equal")
@ -319,5 +328,11 @@
 (assert (= true ;(map truthy? [0 "" true @{} {} [] '()])) "truthy values")
 (assert (= false ;(map truthy? [nil false])) "non-truthy values")

+# Struct and Table duplicate elements
+(assert (= {:a 3 :b 2} {:a 1 :b 2 :a 3}) "struct literal duplicate keys")
+(assert (= {:a 3 :b 2} (struct :a 1 :b 2 :a 3)) "struct constructor duplicate keys")
+(assert (deep= @{:a 3 :b 2} @{:a 1 :b 2 :a 3}) "table literal duplicate keys")
+(assert (deep= @{:a 3 :b 2} (table :a 1 :b 2 :a 3)) "table constructor duplicate keys")
+
 (end-suite)

--- a/test/suite1.janet
+++ b/test/suite1.janet
@ -259,4 +259,26 @@
 (assert (array= (array/slice @[1 2 3] 0 2) @[1 2]) "array/slice 1")
 (assert (array= (array/slice @[0 7 3 9 1 4] 2 -2) @[3 9 1]) "array/slice 2")

+# Even and odd
+
+(assert (odd? 9) "odd? 1")
+(assert (odd? -9) "odd? 2")
+(assert (not (odd? 10)) "odd? 3")
+(assert (not (odd? 0)) "odd? 4")
+(assert (not (odd? -10)) "odd? 5")
+(assert (not (odd? 1.1)) "odd? 6")
+(assert (not (odd? -0.1)) "odd? 7")
+(assert (not (odd? -1.1)) "odd? 8")
+(assert (not (odd? -1.6)) "odd? 9")
+
+(assert (even? 10) "even? 1")
+(assert (even? -10) "even? 2")
+(assert (even? 0) "even? 3")
+(assert (not (even? 9)) "even? 4")
+(assert (not (even? -9)) "even? 5")
+(assert (not (even? 0.1)) "even? 6")
+(assert (not (even? -0.1)) "even? 7")
+(assert (not (even? -10.1)) "even? 8")
+(assert (not (even? -10.6)) "even? 9")
+
 (end-suite)
--- a/test/suite7.janet
+++ b/test/suite7.janet
@ -226,6 +226,23 @@
                :week-day 3}
               (os/date 1388608200)) "os/date")

+# OS mktime test
+
+(assert (= 1388608200 (os/mktime {:year-day 0
+                                  :minutes 30
+                                  :month 0
+                                  :dst false
+                                  :seconds 0
+                                  :year 2014
+                                  :month-day 0
+                                  :hours 20
+                                  :week-day 3})) "os/mktime")
+
+(def now (os/time))
+(assert (= (os/mktime (os/date now)) now) "UTC os/mktime")
+(assert (= (os/mktime (os/date now true) true) now) "local os/mktime")
+(assert (= (os/mktime {:year 1970}) 0) "os/mktime default values")
+
 # Appending buffer to self

 (with-dyns [:out @""]
--- a/test/suite8.janet
+++ b/test/suite8.janet
@ -126,4 +126,119 @@
 (assert (= false (match {:a 1 :b 2 :c 3} {:a a :b _ :c _ :d _} :no {:a _ :b _ :c _} false :no)) "match wildcard 6")
 (assert (= nil (match {:a 1 :b 2 :c 3} {:a a :b _ :c _ :d _} :no {:a _ :b _ :c _} nil :no)) "match wildcard 7")

+# Regression #301
+(def b (buffer/new-filled 128 0x78))
+(assert (= 38 (length (buffer/blit @"" b -1 90))) "buffer/blit 1")
+
+(def a @"abcdefghijklm")
+(assert (deep= @"abcde" (buffer/blit @"" a -1 0 5)) "buffer/blit 2")
+(assert (deep= @"bcde" (buffer/blit @"" a -1 1 5)) "buffer/blit 3")
+(assert (deep= @"cde" (buffer/blit @"" a -1 2 5)) "buffer/blit 4")
+(assert (deep= @"de" (buffer/blit @"" a -1 3 5)) "buffer/blit 5")
+
+# chr
+(assert (= (chr "a") 97) "chr 1")
+
+# Detaching closure over non resumable fiber.
+(do
+  (defn f1
+    [a]
+    (defn f1 [] (++ (a 0)))
+    (defn f2 [] (++ (a 0)))
+    (error [f1 f2]))
+  (def [_ [f1 f2]] (protect (f1 @[0])))
+  # At time of writing, mark phase can detach closure envs.
+  (gccollect)
+  (assert (= 1 (f1)) "detach-non-resumable-closure 1")
+  (assert (= 2 (f2)) "detach-non-resumable-closure 2"))
+
+# Marshal closure over non resumable fiber.
+(do
+  (defn f1
+    [a]
+    (defn f1 [] (++ (a 0)))
+    (defn f2 [] (++ (a 0)))
+    (error [f1 f2]))
+  (def [_ tup] (protect (f1 @[0])))
+  (def [f1 f2] (unmarshal (marshal tup make-image-dict) load-image-dict))
+  (assert (= 1 (f1)) "marshal-non-resumable-closure 1")
+  (assert (= 2 (f2)) "marshal-non-resumable-closure 2"))
+
+# Marshal closure over currently alive fiber.
+(do
+  (defn f1
+    [a]
+    (defn f1 [] (++ (a 0)))
+    (defn f2 [] (++ (a 0)))
+    (marshal [f1 f2] make-image-dict))
+  (def [f1 f2] (unmarshal (f1 @[0]) load-image-dict))
+  (assert (= 1 (f1)) "marshal-live-closure 1")
+  (assert (= 2 (f2)) "marshal-live-closure 2"))
+
+(do
+  (var a 1)
+  (defn b [x] (+ a x))
+  (def c (unmarshal (marshal b)))
+  (assert (= 2 (c 1)) "marshal-on-stack-closure 1"))
+
+# Reduce2
+
+(assert (= (reduce + 0 (range 1 10)) (reduce2 + (range 10))) "reduce2 1")
+(assert (= (reduce * 1 (range 2 10)) (reduce2 * (range 1 10))) "reduce2 2")
+(assert (= nil (reduce2 * [])) "reduce2 3")
+
+# Accumulate
+
+(assert (deep= (accumulate + 0 (range 5)) @[0 1 3 6 10]) "accumulate 1")
+(assert (deep= (accumulate2 + (range 5)) @[0 1 3 6 10]) "accumulate2 1")
+(assert (deep= @[] (accumulate2 + [])) "accumulate2 2")
+(assert (deep= @[] (accumulate 0 + [])) "accumulate 2")
+
+# Perm strings
+
+(assert (= (os/perm-int "rwxrwxrwx") 8r777) "perm 1")
+(assert (= (os/perm-int "rwxr-xr-x") 8r755) "perm 2")
+(assert (= (os/perm-int "rw-r--r--") 8r644) "perm 3")
+
+(assert (= (band (os/perm-int "rwxrwxrwx") 8r077) 8r077) "perm 4")
+(assert (= (band (os/perm-int "rwxr-xr-x") 8r077) 8r055) "perm 5")
+(assert (= (band (os/perm-int "rw-r--r--") 8r077) 8r044) "perm 6")
+
+(assert (= (os/perm-string 8r777) "rwxrwxrwx") "perm 7")
+(assert (= (os/perm-string 8r755) "rwxr-xr-x") "perm 8")
+(assert (= (os/perm-string 8r644) "rw-r--r--") "perm 9")
+
+# Issue #336 cases - don't segfault
+
+(assert-error "unmarshal errors 1" (unmarshal @"\xd6\xb9\xb9"))
+(assert-error "unmarshal errors 2" (unmarshal @"\xd7bc"))
+(assert-error "unmarshal errors 3" (unmarshal "\xd3\x01\xd9\x01\x62\xcf\x03\x78\x79\x7a" load-image-dict))
+(assert-error "unmarshal errors 4"
+              (unmarshal
+                @"\xD7\xCD\0e/p\x98\0\0\x03\x01\x01\x01\x02\0\0\x04\0\xCEe/p../tools
+\0\0\0/afl\0\0\x01\0erate\xDE\xDE\xDE\xDE\xDE\xDE\xDE\xDE\xDE\xDE
+\xA8\xDE\xDE\xDE\xDE\xDE\xDE\0\0\0\xDE\xDE_unmarshal_testcase3.ja
+neldb\0\0\0\xD8\x05printG\x01\0\xDE\xDE\xDE'\x03\0marshal_tes/\x02
+\0\0\0\0\0*\xFE\x01\04\x02\0\0'\x03\0\r\0\r\0\r\0\r" load-image-dict))
+
+# No segfault, valgrind clean.
+
+(def x @"\xCC\xCD.nd\x80\0\r\x1C\xCDg!\0\x07\xCC\xCD\r\x1Ce\x10\0\r;\xCDb\x04\xFF9\xFF\x80\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04uu\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\0\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04}\x04\x04\x04\x04\x04\x04\x04\x04#\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\0\x01\0\0\x03\x04\x04\x04\xE2\x03\x04\x04\x04\x04\x04\x04\x04\x04\x04\x14\x1A\x04\x04\x04\x04\x04\x18\x04\x04!\x04\xE2\x03\x04\x04\x04\x04\x04\x04$\x04\x04\x04\x04\x04\x04\x04\x04\x04\x80\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04\x04A\0\0\0\x03\0\0!\xBF\xFF")
+(unmarshal x load-image-dict)
+(gccollect)
+(marshal x make-image-dict)
+
+(def b @"\xCC\xCD\0\x03\0\x08\x04\rm\xCD\x7F\xFF\xFF\xFF\x02\0\x02\xD7\xCD\0\x98\0\0\x05\x01\x01\x01\x01\x08\xCE\x01f\xCE../tools/afl/generate_unmarshal_testcases.janet\xCE\x012,\x01\0\0&\x03\0\06\x02\x03\x03)\x03\x01\0*\x04\0\00\x03\x04\0>\x03\0\0\x03\x03\0\0*\x05\0\x11\0\x11\0\x05\0\x05\0\x05\0\x05\0\x05\xC9\xDA\x04\xC9\xC9\xC9")
+(unmarshal b load-image-dict)
+(gccollect)
+
+(def v (unmarshal
+  @"\xD7\xCD0\xD4000000\0\x03\x01\xCE\00\0\x01\0\0000\x03\0\0\0000000000\xCC0\0000"
+  load-image-dict))
+(gccollect)
+
+# in vs get regression
+(assert (nil? (first @"")) "in vs get 1")
+(assert (nil? (last @"")) "in vs get 1")
+
 (end-suite)
--- a/tools/afl/README.md
+++ b/tools/afl/README.md
@ -3,12 +3,26 @@
 To use these, you need to install afl (of course), and xterm. A tiling window manager helps manage
 many concurrent fuzzer instances.

+Note, afl sometimes requires system configuration, if you find AFL quitting prematurely, try manually
+launching it and addressing any error messages.
+
 ## Fuzz the parser
 ```
 $ sh ./tools/afl/prepare_to_fuzz.sh
-export NFUZZ=1
+$ export NFUZZ=1
 $ sh ./tools/afl/fuzz.sh parser
 Ctrl+C when done to close all fuzzer terminals.
 $ sh ./tools/afl/aggregate_cases.sh parser
 $ ls ./fuzz_out/parser_aggregated/
-```
+```
+
+## Fuzz the unmarshaller
+```
+$ janet ./tools/afl/generate_unmarshal_testcases.janet
+$ sh ./tools/afl/prepare_to_fuzz.sh
+$ export NFUZZ=1
+$ sh ./tools/afl/fuzz.sh unmarshal
+Ctrl+C when done to close all fuzzer terminals.
+$ sh ./tools/afl/aggregate_cases.sh unmarshal
+$ ls ./fuzz_out/unmarshal_aggregated/
+```
--- a/tools/afl/generate_unmarshal_testcases.janet
+++ b/tools/afl/generate_unmarshal_testcases.janet
@ -0,0 +1,49 @@
+
+(os/mkdir "./tools/afl/unmarshal_testcases/")
+
+(defn spit-case [n v]
+  (spit
+    (string "./tools/afl/unmarshal_testcases/" (string n))
+    (marshal v make-image-dict)))
+
+(def cases [
+  nil
+
+  "abc"
+
+  :def
+
+  'hij
+
+  123
+
+  (int/s64 123)
+
+  "7"
+
+  [1 2 3]
+
+  @[1 2 3]
+
+  {:a 123}
+
+  @{:b 'xyz}
+
+  (peg/compile
+    '{:a (* "a" :b "a")
+      :b (* "b" (+ :a 0) "b")
+      :main (* "(" :b ")")})
+
+  (fn f [a] (fn [] {:ab a}))
+
+  (fn f [a] (print "hello world!"))
+
+  (do
+    (defn f [a] (yield) @[1 "2"])
+    (def fb (fiber/new f))
+    (resume fb)
+    fb)
+])
+
+(eachk i cases
+  (spit-case i (in cases i)))
--- a/tools/afl/unmarshal_runner.janet
+++ b/tools/afl/unmarshal_runner.janet
@ -0,0 +1,6 @@
+# Unmarshal garbage.
+(def v (unmarshal (slurp ((dyn :args) 1)) load-image-dict))
+# Trigger leaks or use after free.
+(gccollect)
+# Attempt to use generated value.
+(marshal v make-image-dict)
--- a/tools/tm_lang_gen.janet
+++ b/tools/tm_lang_gen.janet
@ -308,7 +308,7 @@
      <array>
        <dict>
          <key>match</key>
-          <string>(\\[nevr0zft"\\']|\\x[0-9a-fA-F][0-9a-fA-f])</string>
+          <string>(\\[nevr0zft"\\']|\\x[0-9a-fA-F]{2}|\\u[0-9a-fA-F]{4}|\\U[0-9a-fA-F]{6})</string>
          <key>name</key>
          <string>constant.character.escape.janet</string>
        </dict>