Webiny\Component\Router\Route\RouteCompiler::compile PHP Method

    public static function compile(Route $route)
    {
        $staticPrefix = false;
        $variables = [];
        $pos = 0;
        $extractedRegexes = [];
        $defaults = [];
        // set correct static prefix
        $prefix = $route->getHost() == '' ? '' : $route->getHost() . '/';
        // route regex
        $routePatternObject = self::str($route->getPath())->trimLeft('/');
        // if path is empty
        // e.g. the path is empty if you are matching a start page
        if ($routePatternObject->val() == '') {
            return new CompiledRoute(false, false, [], [], false);
        }
        $routePattern = $prefix . $routePatternObject->val() . '$';
        // we append the regex to match the string from beginning only if the path starts with http or '/'
        if ($routePatternObject->startsWith('http')) {
            $routePattern = '^' . $routePattern;
        } else {
            if (self::str($route->getRealPath())->startsWith('/') && self::str($route->getRealPath())->length() > 1) {
                $routePattern = '^/' . $routePattern;
            }
        }
        // set regex delimiters
        $routePattern = '#' . $routePattern . '#';
        // extract all variables
        preg_match_all('#\\{\\w+\\}#', $route->getPath(), $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
        foreach ($matches as $m) {
            $var = substr($m[0][0], 1, -1);
            // get all the text before the variable
            if (!$staticPrefix) {
                $prefix = substr($route->getPath(), $pos, $m[0][1] - $pos);
                $pos = $m[0][1] + strlen($m[0][0]);
                $precedingChar = strlen($prefix) > 0 ? substr($prefix, -1) : '';
                if (strlen($precedingChar) === 1 && strpos(self::SEPARATORS, $precedingChar) !== false) {
                    $staticPrefix .= substr($prefix, 0, -1);
                } else {
                    $staticPrefix .= $prefix;
                }
            }
            $regex = '[\\w-]+';
            $default = false;
            if ($route->hasOption($var)) {
                // pattern
                if ($route->getOptions()[$var]->hasAttribute('Pattern')) {
                    $regex = $route->getOptions()[$var]->getAttribute('Pattern');
                }
                // default
                if ($route->getOptions()[$var]->hasAttribute('Default')) {
                    $default = $route->getOptions()[$var]->getAttribute('Default');
                }
            }
            $extractedRegexes[$var] = $regex;
            $defaults['{' . $var . '}'] = $default;
            $variables[] = ['name' => $var];
            $routePattern = str_replace($m[0][0], '(' . $regex . ')', $routePattern);
        }
        // build the default route
        $defaultRoute = false;
        if (count($defaults) > 0) {
            $defaultRoute = str_replace(array_keys($defaults), array_values($defaults), $route->getPath());
        }
        return new CompiledRoute($staticPrefix, $routePattern, $variables, $extractedRegexes, $defaultRoute);
    }

 /**
  * Compiles the route object and returns an instance of CompiledRoute.
  *
  * @return CompiledRoute
  */
 public function compile()
 {
     if ($this->isNull($this->compiledRoute)) {
         $this->compiledRoute = RouteCompiler::compile($this);
     }
     return $this->compiledRoute;
 }