Flow\Loader::compile PHP Method

    public function compile($template, $mode = null)
    {
        if (!is_string($template)) {
            throw new \InvalidArgumentException('string expected');
        }
        $source = $this->options['source'];
        $adapter = $this->options['adapter'];
        $path = $this->resolvePath($template);
        $class = self::CLASS_PREFIX . md5($path);
        if (!$adapter->isReadable($path)) {
            throw new \RuntimeException(sprintf('%s is not a valid readable template', $template));
        }
        $target = $this->options['target'] . '/' . $class . '.php';
        if (!isset($mode)) {
            $mode = $this->options['mode'];
        }
        switch ($mode) {
            case self::RECOMPILE_ALWAYS:
                $compile = true;
                break;
            case self::RECOMPILE_NEVER:
                $compile = !file_exists($target);
                break;
            case self::RECOMPILE_NORMAL:
            default:
                $compile = !file_exists($target) || filemtime($target) < $adapter->lastModified($path);
                break;
        }
        if ($compile) {
            try {
                $lexer = new Lexer($adapter->getContents($path));
                $parser = new Parser($lexer->tokenize());
                $compiler = new Compiler($parser->parse());
                $compiler->compile($path, $target);
            } catch (SyntaxError $e) {
                throw $e->setMessage($path . ': ' . $e->getMessage());
            }
        }
        return $this;
    }