每天laravel-20160820| ContextualBinding

<?phpnamespace illuminate\container;use illuminate\contracts\container\contextualbindingbuilder as contextualbindingbuildercontract;class contextualbindingbuilder implements contextualbindingbuildercontract{    /**     * the underlying container instance.     *     * @var \illuminate\container\container     */    protected $container;// the underlying container instance    /**     * the concrete instance.     *     * @var string     */    protected $concrete;// a instance about concrete    /**     * the abstract target.     *     * @var string     */    protected $needs;// a target about the abstract    /**     * create a new contextual binding builder.     *     * @param  \illuminate\container\container  $container     * @param  string  $concrete     * @return void     */    public function __construct(container $container, $concrete)    {        $this->concrete = $concrete;        $this->container = $container;// set the    }    /**     * define the abstract target that depends on the context.     *     * @param  string  $abstract     * @return $this     */    public function needs($abstract)    {        $this->needs = $abstract;        return $this;    }// function is needs    /**     * define the implementation for the contextual binding.     *     * @param  \closure|string  $implementation     * @return void     */    public function give($implementation)    {        $this->container->addcontextualbinding($this->concrete, $this->needs, $implementation);    }// define the implementation for the contextual binding}