Nette\DI\PhpReflection::getParameterType PHP Method

    public static function getParameterType(\ReflectionParameter $param)
    {
        if (PHP_VERSION_ID >= 70000) {
            if ($param->hasType()) {
                $type = PHP_VERSION_ID >= 70100 ? $param->getType()->getName() : (string) $param->getType();
                return strtolower($type) === 'self' ? $param->getDeclaringClass()->getName() : $type;
            }
        } elseif ($param->isArray() || $param->isCallable()) {
            return $param->isArray() ? 'array' : 'callable';
        } else {
            try {
                return ($ref = $param->getClass()) ? $ref->getName() : NULL;
            } catch (\ReflectionException $e) {
                if (preg_match('#Class (.+) does not exist#', $e->getMessage(), $m)) {
                    return $m[1];
                }
                throw $e;
            }
        }
    }

 /**
  * Generates list of arguments using autowiring.
  * @return array
  */
 public static function autowireArguments(\ReflectionFunctionAbstract $method, array $arguments, $container)
 {
     $optCount = 0;
     $num = -1;
     $res = array();
     $methodName = ($method instanceof \ReflectionMethod ? $method->getDeclaringClass()->getName() . '::' : '') . $method->getName() . '()';
     foreach ($method->getParameters() as $num => $parameter) {
         if (array_key_exists($num, $arguments)) {
             $res[$num] = $arguments[$num];
             unset($arguments[$num]);
             $optCount = 0;
         } elseif (array_key_exists($parameter->getName(), $arguments)) {
             $res[$num] = $arguments[$parameter->getName()];
             unset($arguments[$parameter->getName()]);
             $optCount = 0;
         } elseif (($class = PhpReflection::getParameterType($parameter)) && !PhpReflection::isBuiltinType($class)) {
             $res[$num] = $container->getByType($class, FALSE);
             if ($res[$num] === NULL) {
                 if ($parameter->allowsNull()) {
                     $optCount++;
                 } elseif (class_exists($class) || interface_exists($class)) {
                     $rc = new \ReflectionClass($class);
                     if ($class !== ($hint = $rc->getName())) {
                         throw new ServiceCreationException("Service of type {$class} needed by {$methodName} not found, did you mean {$hint}?");
                     }
                     throw new ServiceCreationException("Service of type {$class} needed by {$methodName} not found. Did you register it in configuration file?");
                 } else {
                     throw new ServiceCreationException("Class {$class} needed by {$methodName} not found. Check type hint and 'use' statements.");
                 }
             } else {
                 if ($container instanceof ContainerBuilder) {
                     $res[$num] = '@' . $res[$num];
                 }
                 $optCount = 0;
             }
         } elseif ($parameter->isOptional() || $parameter->isDefaultValueAvailable()) {
             // !optional + defaultAvailable = func($a = NULL, $b) since 5.3.17 & 5.4.7
             // optional + !defaultAvailable = i.e. Exception::__construct, mysqli::mysqli, ...
             $res[$num] = $parameter->isDefaultValueAvailable() ? $parameter->getDefaultValue() : NULL;
             $optCount++;
         } else {
             throw new ServiceCreationException("Parameter \${$parameter->getName()} in {$methodName} has no class type hint or default value, so its value must be specified.");
         }
     }
     // extra parameters
     while (array_key_exists(++$num, $arguments)) {
         $res[$num] = $arguments[$num];
         unset($arguments[$num]);
         $optCount = 0;
     }
     if ($arguments) {
         throw new ServiceCreationException("Unable to pass specified arguments to {$methodName}.");
     }
     return $optCount ? array_slice($res, 0, -$optCount) : $res;
 }