1/*
2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26package jdk.nashorn.api.tree;
27
28/**
29 *  A tree node for <a href="http://www.ecma-international.org/ecma-262/6.0/#sec-generator-function-definitions">yield expressions</a> used in generator functions.
30 *
31 * For example:
32 * <pre>
33 * <em>function*</em> id(){
34 *     var index = 0;
35 *     while(index &lt; 10)
36 *         <em>yield index++;</em>
37 * }
38 * </pre>
39 *
40 * @since 9
41 */
42public interface YieldTree extends ExpressionTree {
43    /**
44     * Returns the expression that is yielded.
45     *
46     * @return The expression that is yielded.
47     */
48    ExpressionTree getExpression();
49
50    /**
51     * Is this a yield * expression in a generator function?
52     *
53     * For example:
54     * <pre>
55     * function* id(){
56     *     yield 1;
57     *     <em>yield * anotherGeneratorFunc();</em>
58     *     yield 10;
59     * }
60     * </pre>
61     *
62     *
63     * @return true if this is a yield * expression
64     */
65    boolean isStar();
66}
67