一个简单的模板类--编译型的(simplet类增强后)

在上次发布的simplet类之后（http://bbs.phpchina.com/thread-85257-1-1.html），发现有很多缺陷，例如不支持多维数组，注释和没有缓存功能，这次我把这些功能都加进去了！！！
大家有兴趣的话，我下次出个教程，来谈谈我写这个类的一些思想和方法！！！支持的话可以跟贴支持我！
PHP代码:
simplet.class.php
<?php
class SimpleT {
    private $t_vars;
    private $templates_dir;
    private $templates_c_dir;
    private $cache;
    private $cache_dir;
   
    public function __construct() {
        $this->templates_dir = ./templates/;
        $this->templates_c_dir = ./templates_c/;
        $this->cache = 0;
        $this->cache_dir = ./cache/;
    }
    public function setDir($dir, $type = template) {
        if(is_dir($dir)) {
            if($type == template)
                $this->templates_dir = rtrim($dir, /)./;
            elseif($type == template_c)
                $this->templates_c_dir = rtrim($dir, /)./;
            elseif($type == cache)
                $this->cache_dir = rtrim($dir, /)./;
            else
                return false;
            return true;
        } else {
            return false;
        }
    }
   
    public function cache($time) {
        if(is_numeric($time)) {
            $this->cache = $time;
            return true;
        } else {
            return false;
        }
    }
   
    public function assign($var, $value = NULL) {
        if (is_array($var)) {
            foreach ($var as $key => $val) {
                $this->t_vars[$key] = $val;
            }
        } else {
            $this->t_vars[$var] = $value;
        }
    }
    private function comp($filename) {
        try {
            if(!$fp = fopen($filename, r)) {
                throw new Exception(Can not open . $filename);
            }
            $filesize = filesize($filename);
            if($filesize <= 0) {
                throw new Exception(The file size must > 0 );
            }
            $content = fread($fp, $filesize);
            fclose($fp);
            unset($fp);
           
            $content = preg_replace("/<%=([$a-zA-Z0-9_]{1,})%>/","<?php echo \$$1 ;?>", $content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,}).loop%>/", "<?php foreach(\$$1 as \$$1_key => \$$1_val) { ?>",$content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,}).loop(([$a-zA-Z0-9_]{1,}))%>/", "<?php foreach(\$$1 as \$$2) { ?>", $content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,}).loop(([$a-zA-Z0-9_]{1,}),([$a-zA-Z0-9_]{1,}))%>/", "<?php foreach(\$$1 as \$$2 => \$$3) { ?>", $content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,}).key%>/", "<?php echo \$$1_key ;?>", $content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,}).value%>/", "<?php echo \$$1_val ;?>", $content);
            $content = preg_replace("/<%([$a-zA-Z0-9_]{1,})\?%>/", "<?php if(\$$1 == true) { ?>", $content);
            $content = preg_replace("/<%end%>/","<?php } ?>", $content);
            $content = preg_replace("/<%##common##%>([^<%##end##%>]{0,})<%##end##%>/", "<?php /* $1 */ ?>", $content);
            if (preg_match_all("/<%{([^(}%>)]{1,})}%>/", $content, $files)) {
                $this->comp($this->templates_dir . $files[1][0]);
            }
            $content = preg_replace("/<%{([^(}%>)]{1,})}%>/", "<?php include {$this->templates_c_dir}simplet_comp_$1.php; ?>", $content);
            echo $content;
            $fp = fopen($this->templates_c_dir . simplet_comp_ . basename($filename) . .php, w);
            if(!fwrite($fp, $content)) {
                throw new Exception(Can not write content in the . $filename);
       &