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/n/* $1 *//n?>", $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 ' . $filename);
            }
            fclose($fp);
        } catch (Exception $e) {
            echo $e->getMessage();
        }
        return true;
    }
    public function display($filename) {
        $filename = $this->templates_dir . $filename;
        if(!file_exists($filename)) {
            return false;
        }
        $t_filename_c = $this->templates_c_dir . 'simplet_comp_' . basename($filename) .'.php';
        if(!file_exists($t_filename_c) || filemtime($t_filename_c) < filemtime($filename)) {
            $this->comp($filename);
        }
        if($this->cache > 0) {
            $cache_file = $this->cache_dir . basename($filename);
            if(!file_exists($cache_file) || (time() - filemtime($cache_file)) > $this->cache) {
                ob_start();
                foreach ($this->t_vars as $key => $val) {
                    $$key = $val;
                }
                include($t_filename_c);
                $content = ob_get_contents();
                ob_end_clean();
                $fp = fopen($cache_file, 'w');
                fwrite($fp, $content);
                fclose($fp);
                echo $content;
                unset($content);
            } else {
                include($cache_file);
            }
        } else {
            foreach ($this->t_vars as $key => $val) {
                $$key = $val;
            }
            include($t_filename_c);
        }
       
    }
}
?>

PHP代码:
test.php

<?php
require_once('simplet.class.php');

$t = new SimpleT();
$t->cache(10);//开启cache功能，并且设置为过期时间为10秒
$t->assign('arrays', array(array('hello','world')));
$t->assign('condition',false);
$t->display('index.php');
?>

PHP代码:
index.php(模板文件，放在templates/文件夹里)

<%##common##%>
这里是注释
下面是多维数组循环
<%##end##%>
<%arrays.loop(value)%>
    <%value.loop(name)%>
        <%=name%>
    <%end%>
<%end%>

<%##common##%>
下面是条件判断
<%##end##%>
<%condition?%>
    <h1>Condition is true</h1>
<%end%>

<%##common##%>
下面是包含文件()
<%##end##%>
<%{filename.php}%>