PHP's trim(chars) in JS and mapping RegExp matches

gistfile1.js

//author: lo sauer 2011 - lsauer.com
//implementation of PHP's trim
//see http://php.net/manual/en/function.trim.php
//bug: doesn't work with ']' in the charlist

//@param: charlist <string>
String.prototype.phptrim = function(s)
{
	if(0==arguments.length)
		return this.valueOf().trim();
	//s = s.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '\\$1');
	var restr = '['+s.split('').join('|')+']*';
	var re = RegExp('^'+restr+'|'+restr+'$','g');
	return this.valueOf().replace(re,'');
}

//without a charlist provided: phptrim == trim, removes:
//you can with this code: "\x0B".trim().length, which should be 0
//" " (ASCII 32 (0x20)), an ordinary space.
//"\t" (ASCII 9 (0x09)), a tab.
//"\n" (ASCII 10 (0x0A)), a new line (line feed).
//"\r" (ASCII 13 (0x0D)), a carriage return.
//"\0" (ASCII 0 (0x00)), the NUL-byte.
//"\x0B" (ASCII 11 (0x0B)), a vertical tab.
//Whitespace list:
//" \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000"

//Examples:
    str = 'Hello I am {{name}}. Is it already the {{date}}...';

    str.match(/\{{2}([a-z0-9]*)\}{2}/gi).
    >>>["{{name}}", "{{date}}"]
    
    //with phptrim
    str.match(/\{{2}([a-z0-9]*)\}{2}/gi).map(function(e){return e.phptrim('{}'); })
    //without phptrim
    str.match(/\{{2}([a-z0-9]*)\}{2}/gi).map(function(e){return e.replace(/\{|\}/g,''); })

    >>>["name", "date"]