[![Build Status](https://travis-ci.org/bakpakin/janet.svg?branch=master)](https://travis-ci.org/bakpakin/janet) [![Appveyor Status](https://ci.appveyor.com/api/projects/status/32r7s2skrgm9ubva?svg=true)](https://ci.appveyor.com/project/bakpakin/janet) Janet logo **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). The language also bridging 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 could be embedded into other programs. Try janet in your browser at [https://janet-lang.org](https://janet-lang.org). # Implemented in mostly standard C99, janet runs on Windows, Linux and macOS. The few features that are not standard C (dynamic library loading, compiler specific optimizations), are fairly straight forward. Janet can be easily ported to new platforms. For syntax highlighting, there is some preliminary vim syntax highlighting in [janet.vim](https://github.com/bakpakin/janet.vim). Generic lisp syntax highlighting should, however, provide good results. There is also a janet.tmLanguage file that should provide good syntax highlighting for many editors. ## Use Cases Janet makes a good system scripting language, or a language to embed in other programs. Think Lua or Guile. ## Features * Minimal setup - one binary and you are good to go! * First class closures * Garbage collection * First class green threads (continuations) * Python style generators (implemented as a plain macro) * Mutable and immutable arrays (array/tuple) * Mutable and immutable hashtables (table/struct) * Mutable and immutable strings (buffer/string) * Lisp Macros * Byte code interpreter with an assembly interface, as well as bytecode verification * Tailcall Optimization * Direct interop with C via abstract types and C functions * Dynamically load C libraries * Functional and imperative standard library * Lexical scoping * Imperative programming as well as functional * REPL * 300+ functions and macros in the core library * Interactive environment with detailed stack traces ## Documentation Documentation can be found in the doc directory of the repository. There is an introduction section contains a good overview of the language. API documentation for all bindings can also be generated with `make docs`, which will create `build/doc.html`, which can be viewed with any web browser. This includes all forms in the core library except special forms. For individual bindings from within the REPL, use the `(doc symbol-name)` macro to get API documentation for the core library. For example, ``` (doc doc) ``` Shows documentation for the doc macro. To get a list of all bindings in the default environment, use the `(all-symbols)` function. ## Installation Install a stable version of janet from the [releases page](https://github.com/bakpakin/janet/releases). Janet is prebuilt for a few systems, but if you want to develop janet, run janet on a non-x86 system, or get the latest, you must build janet from source. ## Usage A repl is launched when the binary is invoked with no arguments. Pass the -h flag to display the usage information. Individual scripts can be run with `./janet myscript.janet` If you are looking to explore, you can print a list of all available macros, functions, and constants by entering the command `(all-symbols)` into the repl. ``` $ ./janet Janet 0.0.0 alpha Copyright (C) 2017-2018 Calvin Rose janet:1:> (+ 1 2 3) 6 janet:2:> (print "Hello, World!") Hello, World! nil janet:3:> (os.exit) $ ./janet -h usage: ./janet [options] scripts... Options are: -h Show this help -v Print the version string -s Use raw stdin instead of getline like functionality -e Execute a string of janet -r Enter the repl after running all scripts -p Keep on executing if there is a top level error (persistent) -- Stop handling option $ ``` ## Compiling and Running Janet only uses Make and batch files to compile on Posix and windows respectively. To configure janet, edit the header file src/include/janet/janet.h before compilation. ### Unix-like On most platforms, use Make to build janet. The resulting binary will be in `build/janet`. ```sh cd somewhere/my/projects/janet make make test ``` After building, run `make install` to install the janet binary and libs. Will install in `/usr/local` by default, see the Makefile to customize. It's also recommended to set the `JANET_PATH` variable in your profile. This is where janet will look for imported libraries after the current directory. ### FreeBSD FreeBSD build instructions are the same as the unix-like build instuctions, but you need `gmake` and `gcc` to compile. ``` cd somewhere/my/projects/janet gmake CC=gcc gmake test CC=gcc ``` ### Windows 1. Install [Visual Studio](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=Community&rel=15#) or [Visual Studio Build Tools](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=BuildTools&rel=15#) 2. Run a Visual Studio Command Prompt (cl.exe and link.exe need to be on the PATH) and cd to the directory with janet. 3. Run `build_win` to compile janet. 4. Run `build_win test` to make sure everything is working. ### Emscripten To build janet for the web via [Emscripten](https://kripken.github.io/emscripten-site/), make sure you have `emcc` installed and on your path. On a linux or macOS system, use `make emscripten` to build `janet.js` and `janet.wasm` - both are needed to run janet in a browser or in node. The JavaScript build is what runs the repl on the main website, but really serves mainly as a proof of concept. Janet will run slower in a browser. Building with emscripten on windows is currently unsupported. ## Examples See the examples directory for some example janet code.