RumCoke - JavaScript in S-Expression

RumCoke is a programming language which has lisp syntax and JavaScript semantics. The idea is, "What if CoffeeScript is based on S-Expression?"

Current state

Experimental

Features

• Traslated into (relatively) readable JavaScript
• Scheme-like syntax
• Array based s-expression
  • '(1 2 3) is an array, not list
• quasiquote

TODO

• User defined macro
• Source Map?

Example

Hello World

(console.log "Hello, world!")

Requirements

Node.js (tested with v0.10.20)

Install

Via npm.org:

$ npm install -g rumcoke
$ rumcoke hello.rmk | node
Hello, world!

Via github:

$ git clone https://github.com/yhara/rumcoke
$ npm install
$ ./bin/rumcoke hello.rmk | node
Hello, world!

Documents

See doc/index.md

Cheat Sheet

Naming rules

• convert-defvar => convertDefvar
• array? => isArray

Variable

• (define a 1) => var a=1;
• (set! x 1) => x = 1;

Property

• (~ ary 0) => ary[0]
• obj.foo => obj.foo
• (aset! obj "foo" 1) => obj.foo = 1;
• cf. (aset! obj foo 1) => obj[foo] = 1;

Function

• (define (f x) x) => var f = function(x){ return x; }
• (^(x) (+ x 1)) => function(x){ return x + 1; }
• (obj.foo 1 2 3) => obj.foo(1, 2, 3);

Literal

• #t => true
• #f => false
• 123 => 123
• "foo" => "foo"
• (array 1 2 3) => [1, 2, 3]
• (array) => []
• (a: 1) => {a: 1}
• ("a?": 1) => {"a?": 1}

Operator

• (= x y) => x === y
• (not (= x y)) => x !== y
• (instance? x Date) => x instanceof Date

Exception

• (throw "err") => throw("err");

Underscore.js

(define _ (require "underscore")) (util.puts (util.inspect (_.map (array 1 2 3) (^(x) (* x 2)))))

See translator.rmk for more.

Development

RumCoke is a self-hosted compiler, so you need a working RumCoke compiler to compile translator.rmk. For this purpose lib/rumcoke/translator.js is commited in repository.

When you run make, it will build translator.js under debug/, so that we always have 'previous working version' in a working copy. make accept will copy this debug build to lib/.

1. modify parser or translator

2. Run test

   $ make test ;=> OK if no error is shown

3. Run make accept to build lib/*

4. Commit

Tips

Sometimes you find bug in the 'previous woking version'. This case is pretty complecated because you are editing translator.rmk but there is a bug in another position of translator.rmk.

In this case, you should:

1. Stop developing the new feature
2. Make a minimal case to reproduce the error (save it in a.rmk)
3. git stash and fix the bug first

How to release

1. Edit ./lib/rumcoke/version.js
2. Edit "version" in ./package.json
3. git ci && git tag vX.Y.Z && git push --tags
4. npm publish .

Why?

• An experiment to make a sexp-based CoffeeScript

  • JavaScript and Scheme are both lisp-2, have 1st-class functions, ...

• An experiment to make an array-based lisp (not list)

  • So there is no 'Dot pair' in RumCoke

• Wanted to make a self-hosted programming language

• I am author of BiwaScheme, a Scheme interpreter written in JavaScript, and envious of languages that translated into JavaScirpt (such as JSX, TypeScript, Haxe). They are sometimes even faster than hand-written JavaScript.

License

MIT

Contact

https://github.com/yhara/rumcoke

Yutaka HARA (yhara)

twitter: @yhara_en