loop-recur

gistfile1.js

//assume args is an array
var partial = function(fn, args1) {
  return function() {
    var args2 = Array.protoype.slice.call(arguments);
    return fn.apply(this. args1.concat(args2));
  };
};

var loop = function(fn) {
  return function() {
    var self = this;
    var args  = Array.prototype.slice.call(arguments);
    args.pop(); //the last argument is a callback
    var cb    = Array.prototype.slice.call(arguments, -1)[0]
    var recur = function() {
      var recurArgs = Array.prototype.slice.call(arguments);
      //this clears the callstack
      setTimeout(function() {
        try {
          var result = fn.apply(self, [recur].concat(recurArgs));
          if (result !== undefined) {
            cb(null, result);
          }
        } catch(err) {
          cb(err, null);
        }
      }, 0);
    }
    try {
      var result = fn.apply(self,[recur].concat(args));
      if (result !== undefined) {
        cb(null, result);
      }
    } catch(err) {
      cb(err, null);
    }
  }
};

module.exports = loop;