Четные и нечетные элементы в циклах

klein.php

@@ -9,12 +9,12 @@ class Klein {
             $body = strtr($grammar[0], [" " => "\s*", "+" => "\s+", ":var" => "(\w+(\s*\.\s*\w+)*)", ":id" => "(\w+)"]);
             return ["/$body/",
                 function ($x) use ($result) {
-                    return "<?php " . preg_replace_callback("/#(\d+)/", function ($s) use($x) {
+                    return "<?php " . preg_replace_callback("/#([\d\w]+)/", function ($s) use($x) {
                         return preg_replace("/\.\s*(\w+)/", "['$1']", $x[$s[1]]);
                     }, $result) . " ?>";
                 }];
         }, [
-            ["{% for+:id+in+:var %}", "foreach(\$#2 as \$index => \$#1): \$loop = ['first' => \$index == 0, 'last' => \$index == count(\$#2) - 1];"],
+            ["{% for+:id+in+:var %}", "foreach(\$#2 as \$index => \$#1): \$loop = Klein::loop(\$index, \$#2);"],
             ["{% for+:id , :id+in+:var %}", "foreach(\$#3 as \$#1 => \$#2):"],
             ["{% endfor %}", "endforeach;"],
             ["{% if+:var %}", "if(isset(\$#1) && \$#1 ):"],
@@ -31,6 +31,14 @@ class Klein {
         $this->code = $result;
     }
 
+    static function loop($idx, &$array) {
+        $is_even =  $idx % 2;
+        return ['first' => $idx == 0
+                , 'last' => $idx == count($array) - 1
+                , 'odd' => !$is_even
+                , 'even' => $is_even];
+    }        
+
     function render($vars) {
         extract($vars);
         ob_start();

template2.html

@@ -1,7 +1,7 @@
 <div>
 {% for var in content %}
     {% for key, value in var %}
-        {{key}} - {{value}}
+    <b>{{key}} - {{value}}</b>
     {% endfor %}
 {% endfor %}
 </div>