eval_block.php

function evaluate_block($block, $arguments = array()) {
    # implict return
    $lines = explode(';', $block);
    $last =& $lines[count($lines)-2];
    if (strpos($last, 'return') === false) {
      $last = 'return '.$last; 
    }
    $block = join(';', $lines);

    if (isset($arguments['this'])) {
        $arguments['self'] = $arguments['this'];
        unset($arguments['this']);
    }
    unset($arguments['block']);
    extract($arguments);
    return eval($block);
}

evaluate_block_test.php

echo "***INJECT***\n";
print_r($e->inject(array(), '#| $object, $key, $value |
  $object["injected_$key"] = $value;
  $object;
'));


$e->map('$object->id;');