partial + partialRight

functional.js

var partial = function partial(fn){
  var args = Array.apply(null, arguments).slice(1);
  return function(){
    var lastArgs = Array.apply(null, arguments);
    return fn.apply(this, args.concat(lastArgs));
  };
};

var partialRight = function partialRight(fn){
  var args = Array.apply(null, arguments).slice(1);
  return function(){
    var firstArgs = Array.apply(null, arguments);
    return fn.apply(this, firstArgs.concat(args));
  };
};