/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file, and Oracle licenses the original version of this file under the BSD

 * license:

 */

/*

   Copyright 2016 Attila Szegedi

*/

package jdk.dynalink;

/**

 * An enumeration of standard namespaces defined by Dynalink.

 */

public enum StandardNamespace implements Namespace {

    /**

     * Standard namespace for properties of an object.

     */

    PROPERTY,

    /**

     * Standard namespace for elements of a collection object.

     */

    ELEMENT,

    /**

     * Standard namespace for methods of an object. The method objects retrieved

     * through a {@link StandardOperation#GET} on this namespace can be (and where

     * object semantics allows they should be) unbound, that is: not bound to the

     * object they were retrieved through. When they are used with

     * {@link StandardOperation#CALL} an explicit "this" receiver argument is always

     * passed to them. Of course bound methods can be returned if the object semantics

     * requires them and such methods are free to ignore the receiver passed in the

     * {@code CALL} operation or even raise an error when it is different from the one

     * the method is bound to, or exhibit any other behavior their semantics requires

     * in such case.

     */

    METHOD;

    /**

     * If the passed in operation is a {@link NamespaceOperation}, or a

     * {@link NamedOperation} wrapping a {@link NamespaceOperation}, then it

     * returns the first (if any) {@link StandardNamespace} in its namespace

     * list. If the passed operation is not a namespace operation (optionally

     * wrapped in a named operation), or if it doesn't have any standard

     * namespaces in it, returns {@code null}.

     * @param op the operation

     * @return the first standard namespace in the operation's namespace list

     */

    public static StandardNamespace findFirst(final Operation op) {

        for(final Namespace ns: NamespaceOperation.getNamespaces(NamedOperation.getBaseOperation(op))) {

            if (ns instanceof StandardNamespace) {

                return (StandardNamespace)ns;

            }

        }

        return null;

    }

}