Symfony\Component\Routing\Matcher\Dumper\PhpMatcherDumper::compileRoutes PHP Method

    private function compileRoutes(RouteCollection $routes, $supportsRedirections, $parentPrefix = null)
    {
        $code = array();

        $routes = clone $routes;
        $routeIterator = $routes->getIterator();
        $keys = array_keys($routeIterator->getArrayCopy());
        $keysCount = count($keys);

        $i = 0;
        foreach ($routeIterator as $name => $route) {
            $i++;

            $route = clone $route;
            if ($route instanceof RouteCollection) {
                $prefix = $route->getPrefix();
                $optimizable = $prefix && count($route->all()) > 1 && false === strpos($route->getPrefix(), '{');
                $indent = '';
                if ($optimizable) {
                    for ($j = $i; $j < $keysCount; $j++) {
                        if ($keys[$j] === null) {
                          continue;
                        }

                        $testRoute = $routeIterator->offsetGet($keys[$j]);
                        $isCollection = ($testRoute instanceof RouteCollection);

                        $testPrefix = $isCollection ? $testRoute->getPrefix() : $testRoute->getPattern();

                        if (0 === strpos($testPrefix, $prefix)) {
                            $routeIterator->offsetUnset($keys[$j]);

                            if ($isCollection) {
                                $route->addCollection($testRoute);
                            } else {
                                $route->add($keys[$j], $testRoute);
                            }

                            $i++;
                            $keys[$j] = null;
                        }
                    }

                    if ($prefix !== $parentPrefix) {
                        $code[] = sprintf("        if (0 === strpos(\$pathinfo, %s)) {", var_export($prefix, true));
                        $indent = '    ';
                    }
                }

                foreach ($this->compileRoutes($route, $supportsRedirections, $prefix) as $line) {
                    foreach (explode("\n", $line) as $l) {
                        if ($l) {
                            $code[] = $indent.$l;
                        } else {
                            $code[] = $l;
                        }
                    }
                }

                if ($optimizable && $prefix !== $parentPrefix) {
                    $code[] = "        }\n";
                }
            } else {
                foreach ($this->compileRoute($route, $name, $supportsRedirections, $parentPrefix) as $line) {
                    $code[] = $line;
                }
            }
        }

        return $code;
    }