JavaScript: String.prototype.filter

String.prototype.filter.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * String.prototype.filter
 *
 * Allows for an arbitrary number of arguments which take a string as a single
 * parameter, and return a string, to modify the string.
 *
 * @example
 * 	'  This is my string '.filter(String.trim, function(str){return str + '!';}, String.bold);
 * 	// returns '<b>This is my string!</b>'
 *
 * @author William Duyck <[email protected]>
 */
if ( !String.prototype.filter ) {
	String.prototype.filter = function() {
		'use strict';

		var args = Array.prototype.slice.call( arguments );
		var str = this;

		args.forEach( function( fn ) {
			str = fn.call( str, str );
		});

		return str;
	};
}