/*----------------------------------------------------------------------------\
|                             String Builder 1.02                             |
|-----------------------------------------------------------------------------|
|                         Created by Erik Arvidsson                           |
|                  (http://webfx.eae.net/contact.html#erik)                   |
|                      For WebFX (http://webfx.eae.net/)                      |
|-----------------------------------------------------------------------------|
| A class that allows more efficient building of strings than concatenation.  |
|-----------------------------------------------------------------------------|
|                  Copyright (c) 1999 - 2002 Erik Arvidsson                   |
|-----------------------------------------------------------------------------|
| This software is provided "as is", without warranty of any kind, express or |
| implied, including  but not limited  to the warranties of  merchantability, |
| fitness for a particular purpose and noninfringement. In no event shall the |
| authors or  copyright  holders be  liable for any claim,  damages or  other |
| liability, whether  in an  action of  contract, tort  or otherwise, arising |
| from,  out of  or in  connection with  the software or  the  use  or  other |
| dealings in the software.                                                   |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| This  software is  available under the  three different licenses  mentioned |
| below.  To use this software you must chose, and qualify, for one of those. |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| The WebFX Non-Commercial License          http://webfx.eae.net/license.html |
| Permits  anyone the right to use the  software in a  non-commercial context |
| free of charge.                                                             |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| The WebFX Commercial license           http://webfx.eae.net/commercial.html |
| Permits the  license holder the right to use  the software in a  commercial |
| context. Such license must be specifically obtained, however it's valid for |
| any number of  implementations of the licensed software.                    |
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - |
| GPL - The GNU General Public License    http://www.gnu.org/licenses/gpl.txt |
| Permits anyone the right to use and modify the software without limitations |
| as long as proper  credits are given  and the original  and modified source |
| code are included. Requires  that the final product, software derivate from |
| the original  source or any  software  utilizing a GPL  component, such  as |
| this, is also licensed under the GPL license.                               |
|-----------------------------------------------------------------------------|
| 2000-10-02 | First version                                                  |
| 2000-10-05 | Added a cache of the string so that it does not need to be     |
|            | regenerated every time in toString                             |
| 2002-10-03 | Added minor improvement in the toString method                 |
|-----------------------------------------------------------------------------|
| Created 2000-10-02 | All changes are in the log above. | Updated 2002-10-03 |
\----------------------------------------------------------------------------*/ function StringBuilder(sString) {
	
	// public
	this.length = 0;
	
	this.append = function (sString) {
		// append argument
		this.length += (this._parts[this._current++] = String(sString)).length;
		
		// reset cache
		this._string = null;
		return this;
	};
	
	this.toString = function () {
		if (this._string != null)
			return this._string;
		
		var s = this._parts.join("");
		this._parts = [s];
		this._current = 1;
		this.length = s.length;
		
		return this._string = s;
	};

	// private
	this._current	= 0;
	this._parts		= [];
	this._string	= null;	// used to cache the string
	
	// init
	if (sString != null)
		this.append(sString);
}