用PHP实现简单的反向最大匹配中文分词（代码）

类文件wordsplit.class.php：
<?php
/********************************************************************
* DirCMS中文分词类 beta 1.0
* ---------------------------
* begin : 2010-5-11 beta 1.0
* update : 2010-5-11 beta 1.0
* copyright : (C) 2009 DirCMS
* email : uuturn@126.com
* author : 穆红伟 M QQ:251171960
* algorithm : 反向最大匹配算法 【注意：本文件需保存为UTF-8格式】
*
* $Id: wordsplit.class.php,v 1.0.0 2010-5-11 9:14:01 M Exp $
********************************************************************/
class wordsplit
{
public $dicloadtime; // 词典载入时间
public $splitwordstime; // 分词时间
private $starttime; // 分词开始时间
private $splitchar=' '; // 切割符，默认为空格
private $wordsdic=array(); // 词库（为键值为词，值为词频的数组） 本分次尚未用到词频
private $cnnumber='０|１|２|３|４|５|６|７|８|９|＋|－|％|．|ａ|ｂ|ｃ|ｄ|ｅ|ｆ|ｇ|ｈ|ｉ|ｊ|ｋ|ｌ|ｍ|ｎ|ｏ|ｐ|ｑ|ｒ|ｓ|ｔ|ｕ|ｖ|ｗ|ｘ|ｙ|ｚ|Ａ|Ｂ|Ｃ|Ｄ|Ｅ|Ｆ|Ｇ|Ｈ|Ｉ|Ｊ|Ｋ|Ｌ|Ｍ|Ｎ|Ｏ|Ｐ|Ｑ|Ｒ|Ｓ|Ｔ|Ｕ|Ｖ|Ｗ|Ｘ|Ｙ|Ｚ'; // 中文全角字母，数字
private $punctuation= array('\r','\n','\t','`','~','!','@','#','$','%','^','&','*','(',')','-','_','+','=','|','\\','\'','"',';',':','/','?','.','>',',','<','[','{',']','}','·','～','！','＠','＃','￥','％','……','＆','×','（','）','－','——','＝','＋','＼','｜','【','｛','】','｝','‘','“','”','；','：','、','？','。','》','，','《',' ','　'); // 标点符号
private $trimchars=array("▲","△","▼","▽","★","☆","◆","◇","■","□","●","○","⊙","㊣","◎","▂","▁","▃","▄","▅","▆","▇","█","▏","▎","▍","▌","▋","▊","◢","◣","◥","◤","▲","▼","♀","♂","卍","※");
private $resultstr=array(); //分词结果字