Refactored PHP engine makes Wordpress 20% faster(news.php.net)

    $image_urls = array_map(compose(papply('concat', 'illos/'), papply('lookup', 'url')),
                            $images);

    // Function composition
    function compose($f, $g) {
      return function() use ($f, $g) {
        return $f(call_user_func_array($g, func_get_args()));
      };
    }

    // String concatenation. Unfortunately we can't write "concat = papply('implode', '')"
    function concat() {
      return implode('', func_get_args());
    }

    // Array subscript. I'd prefer to do this the other way around and write an
    // argument-flipping function, but that's unnecessary for this example
    function lookup($x, $y) {
      return $y[$x];
    }

    // Partial application
    function papply() {
      $args = func_get_args();
      return function() use ($args) {
        return call_user_func_array('call_user_func',
                                    array_merge($args, func_get_args()));
      };
    }

    $image_urls = array_map(function($image) {return 'illos/'. $image['url'];}, $images);

  image_urls = images.map { |img| "illos/#{img}" }