eholder);

            if ($value !== $placeholder) {
                Arr::set($results, $key, $value);
            }
        }

        return $results;
    }

    /**
     * Get all of the input except for a specified array of items.
     *
     * @param  array|mixed  $keys
     * @return array
     */
    public function except($keys)
    {
        $keys = is_array($keys) ? $keys : func_get_args();

        $results = $this->all();

        Arr::forget($results, $keys);

        return $results;
    }

    /**
     * Retrieve a query string item from the request.
     *
     * @param  string|null  $key
     * @param  string|array|null  $default
     * @return string|array|null
     */
    public function query($key = null, $default = null)
    {
        return $this->retrieveItem('query', $key, $default);
    }

    /**
     * Retrieve a request payload item from the request.
     *
     * @param  string|null  $key
     * @param  string|array|null  $default
     * @return string|array|null
     */
    public function post($key = null, $default = null)
    {
        return $this->retrieveItem('request', $key, $default);
    }

    /**
     * Determine if a cookie is set on the request.
     *
     * @param  string  $key
     * @return bool
     */
    public function hasCookie($key)
    {
        return ! is_null($this->cookie($key));
    }

    /**
     * Retrieve a cookie from the request.
     *
     * @param  string|null  $key
     * @param  string|array|null  $default
     * @return string|array|null
     */
    public function cookie($key = null, $default = null)
    {
        return $this->retrieveItem('cookies', $key, $default);
    }

    /**
     * Get an array of all of the files on the request.
     *
     * @return array
     */
    public function allFiles()
    {
        $files = $this->files->all();

        return $this->convertedFiles = $this->convertedFiles ?? $this->convertUploadedFiles($files);
    }

    /**
     * Convert the given array of Symfony UploadedFiles to custom Laravel UploadedFiles.
     *
     * @param  array  $files
     * @return array
     */
    protected function convertUploadedFiles(array $files)
    {
        return array_map(function ($file) {
            if (is_null($file) || (is_array($file) && empty(array_filter($file)))) {
                return $file;
            }

            return is_array($file)
                        ? $this->convertUploadedFiles($file)
                        : UploadedFile::createFromBase($file);
        }, $files);
    }

    /**
     * Determine if the uploaded data contains a file.
     *
     * @param  string  $key
     * @return bool
     */
    public function hasFile($key)
    {
        if (! is_array($files = $this->file($key))) {
            $files = [$files];
        }

        foreach ($files as $file) {
            if ($this->isValidFile($file)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Check that the given file is a valid file instance.
     *
     * @param  mixed  $file
     * @return bool
     */
    protected function isValidFile($file)
    {
        return $file instanceof SplFileInfo && $file->getPath() !== '';
    }

    /**
     * Retrieve a file from the request.
     *
     * @param  string|null  $key
     * @param  mixed  $default
     * @return \Illuminate\Http\UploadedFile|\Illuminate\Http\UploadedFile[]|array|null
     */
    public function file($key = null, $default = null)
    {
        return data_get($this->allFiles(), $key, $default);
    }

    /**
     * Retrieve a parameter item from a given source.
     *
     * @param  string  $source
     * @param  string  $key
     * @param  string|array|null  $default
     * @return string|array|null
     */
    protected function retrieveItem($source, $key, $default)
    {
        if (is_null($key)) {
            return $this->$source->all();
        }

        return $this->$source->get($key, $default);
    }

    /**
     * Dump the request items and end the script.
     *
     * @param  mixed  $keys
     * @return void
     */
    public function dd(...$keys)
    {
        $this->dump(...$keys);

        exit(1);
    }

    /**
     * Dump the items.
     *
     * @param  mixed  $keys
     * @return $this
     */
    public function dump($keys = [])
    {
        $keys = is_array($keys) ? $keys : func_get_args();

        VarDumper::dump(count($keys) > 0 ? $this->only($keys) : $this->all());

        return $this;
    }
}