<?php
  
  namespace Illuminate\Contracts\Config;
  
  interface Repository
  {
      /**
       * Determine if the given configuration value exists.
       *
       * @param  string  $key
       * @return bool
       */
      public function has($key);
  
      /**
       * Get the specified configuration value.
       *
       * @param  array|string  $key
       * @param  mixed  $default
       * @return mixed
       */
      public function get($key, $default = null);
  
      /**
       * Get all of the configuration items for the application.
       *
       * @return array
       */
      public function all();
  
      /**
       * Set a given configuration value.
       *
       * @param  array|string  $key
       * @param  mixed  $value
       * @return void
       */
      public function set($key, $value = null);
  
      /**
       * Prepend a value onto an array configuration value.
       *
       * @param  string  $key
       * @param  mixed  $value
       * @return void
       */
      public function prepend($key, $value);
  
      /**
       * Push a value onto an array configuration value.
       *
       * @param  string  $key
       * @param  mixed  $value
       * @return void
       */
      public function push($key, $value);
  }