Regular Expressions As Functions

see http://blog.stevenlevithan.com/archives/regular-expressions-as-functions

RegExp.prototype.call = function (context, str) {
		return this.exec(str);
	};
	RegExp.prototype.apply = function (context, args) {
		return this.exec(args[0]);
	};
	
	// Returns an array with the elements of an existng array for which the provided filtering function returns true
	Array.prototype.filter = function (func, context) {
		var results = [];
		for (var i = 0; i < this.length; i++) {
			if (i in this && func.call(context, this[i], i, this))
				results.push(this[i]);
		}
		return results;
	};
	// Returns true if every element in the array satisfies the provided testing function
	Array.prototype.every = function (func, context) {
		for (var i = 0; i < this.length; i++) {
			if (i in this && !func.call(context, this[i], i, this))
				return false;
		}
		return true;
	};
	// Returns true if at least one element in the array satisfies the provided testing function
	Array.prototype.some = function (func, context) {
		for (var i = 0; i < this.length; i++) {
			if (i in this && func.call(context, this[i], i, this))
				return true;
		}
		return false;
	};
	// Returns an array with the results of calling the provided function on every element in the provided array
	Array.prototype.map = function (func, context) {
		var results = [];
		for (var i = 0; i < this.length; i++) {
			if (i in this)
				results[i] = func.call(context, this[i], i, this);
		}
		return results;
	};
	
	var a=["a","b","ab","ba"].filter(/^a/);
	alert(a);
	if(window.console && window.console.log)console.log(a);