prototype/src/lang/function.js

Object.extend(Function.prototype, (function() {
  var slice = Array.prototype.slice;
  
  function update(array, args) {
    var arrayLength = array.length, length = args.length;
    while (length--) array[arrayLength + length] = args[length];
    return array;
  }
  
  function merge(array, args) {
    array = slice.call(array, 0);
    return update(array, args);
  }
  
  function argumentNames() {
    var names = this.toString().match(/^[\s\(]*function[^(]*\(([^\)]*)\)/)[1]
      .replace(/\s+/g, '').split(',');
    return names.length == 1 && !names[0] ? [] : names;
  }

  function bind(context) {
    if (arguments.length < 2 && Object.isUndefined(arguments[0])) return this;
    var __method = this, args = slice.call(arguments, 1);
    return function() {
      var a = merge(args, arguments);
      return __method.apply(context, a);
    }
  }

  function bindAsEventListener(context) {
    var __method = this, args = slice.call(arguments, 1);
    return function(event) {
      var a = update([event || window.event], args);
      return __method.apply(context, a);
    }
  }

  function curry() {
    if (!arguments.length) return this;
    var __method = this, args = slice.call(arguments, 0);
    return function() {
      var a = merge(args, arguments);
      return __method.apply(this, a);
    }
  }

  function delay(timeout) { 
    var __method = this, args = slice.call(arguments, 1);
    timeout = timeout * 1000
    return window.setTimeout(function() {
      return __method.apply(__method, args);
    }, timeout);
  }

  function defer() {
    var args = update([0.01], arguments);
    return this.delay.apply(this, args);
  }

  function wrap(wrapper) {
    var __method = this;
    return function() {
      var a = update([__method.bind(this)], arguments);
      return wrapper.apply(this, a);
    }
  }

  function methodize() {
    if (this._methodized) return this._methodized;
    var __method = this;
    return this._methodized = function() {
      var a = update([this], arguments);
      return __method.apply(null, a);
    };
  }
  
  return {
    argumentNames:       argumentNames,
    bind:                bind,
    bindAsEventListener: bindAsEventListener,
    curry:               curry,
    delay:               delay,
    defer:               defer,
    wrap:                wrap,
    methodize:           methodize
  }
})());