> function指令可以把指定的標簽定義為一個函數, 在需要的地方調用
~~~
<div class="menu">
<ul php-function="echo_ul($list)">
<li php-foreach="$list as $cate">
<a href="/category/{$cate.name}">{$cate.title}</a>
<ul php-if="isset($cate['_child'])" php-call="echo_ul($cate['_child'])"></ul>
</li>
</ul>
<ul php-call="echo_ul($list)"></ul>
</div>
~~~
解析后
~~~
<div class="menu">
<?php function echo_ul($list) { ?><ul >
<?php foreach ($list as $cate) { ?><li >
<a href="/category/<?php echo $cate["name"]; ?>"><?php echo $cate["title"]; ?></a>
<?php if (isset($cate['_child'])) { echo_ul($cate['_child']); } ?>
</li><?php } ?>
</ul><?php } echo_ul($list); ?>
</div>
~~~
> 此示例本身就是一個無限級菜單展示的案例, php-call為調用函數傳入數據
