CommonJS implementation of Polyglot for Rhino.

main.js

var polyglot = require('polyglot');
polyglot.register('coffee', require('coffee-script').CoffeeScript.compile);

polyglot.require('math').square(2);

math.coffee

exports.square = (x) -> x * x

polyglot.js

var compilers = {'js': function(source){return source;}};

function register(ext, compile){
  compilers[ext] = compile;
}

function contents(lib){
  for(var ext in compilers){
    for(var index in require.paths){
      var f = new java.io.File(require.paths[index], lib + '.' + ext);
      if(f.exists()){
        return compilers[ext](readFile(f.path));
      }else{
        continue;
      }
    }
  }
  throw "Module not found: " + lib;
}

function sandbox(){
  var ctx = Packages.org.mozilla.javascript.Context.enter();
  var scope = ctx.initStandardObjects();
  ctx.evaluateString(scope, "var exports = {};", "sandbox", 1, null);
  return scope;
}

function req(lib){
  var ctx = Packages.org.mozilla.javascript.Context.enter();
  var scope = sandbox();
  ctx.evaluateString(scope, contents(lib), lib, 0, null);
  return ctx.evaluateString(scope, "exports", "exports", 0, null);
}

exports.require = req;
exports.register = register;