test.php

<?php
$template = tplite();
$callback = function($s){print $s;};
$template(file_get_contents('test.tpl'), [
    'title'=>'test title',
    'messages' => ['test message1', 'test messages2']
], $callback);
?>

test.tpl

<h1>{{$title}}</h1>

{% foreach($messages as $message){ %}
  <p>{{$message}}</p>
{% } %}

tpl.php

<?php 
function tplite($tmpl) {
    return create_function('$d, $c', 'extract($d);'. str_replace(['{{', '}}', '{%', '%}'], ['");$c(', ');$c("', '");', ' $c("'], '%}'. $tmpl. '{%'));
}

$t = tplite(file_get_contents('test.tpl'));
$t([
    'title' => 'test title',
    'messages' => ['message1', 'message2', 'message3']
], function($str){ echo $str; }); 
?>

tplite.php

<?php
function tplite(){
    $_cache = [];
    return function ($tmpl, $data=null, $cb=null) use (&$_cache) {
        if (!isset($_cache[$key = md5($tmpl)])) $func = $_cache[$key] = create_function('$data, $c', 'extract($data);'. str_replace(['{{', '}}', '{%', '%}'], ['");$c(', ');$c("', '");', ' $c("'], '%}'. $tmpl. '{%'));
        return $data && $cb ? $func($data, $cb) : $func;
    };
}