protected function compile_default_structures($value) {

        $value = preg_replace('/(?(R)\((?:[^\(\)]|(?R))*\)|(?<!\w)(\s*)@(if|foreach|for|while)(\s*(?R)+))/', '$1<?php $2 $3 { ?>', $value);
        $value = preg_replace('/(\s*)@elseif(\s*\(.*\))/', '$1<?php } elseif$2 { ?>', $value);
        $value = preg_replace('/(\s*)@(endif|endforeach|endfor|endwhile)(\s*)/', '$1<?php } ?>$3', $value);
        $value = preg_replace('/(\s*)@(end)(\s*)/', '$1<?php } ?>$3', $value);

        return $value;
    }