IndexNode.java revision 1068:34ef988d5959 
1/*
2 * Copyright (c) 2010, 2013, 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
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package jdk.nashorn.internal.ir;
27
28import jdk.nashorn.internal.codegen.types.Type;
29import jdk.nashorn.internal.ir.annotations.Immutable;
30import jdk.nashorn.internal.ir.visitor.NodeVisitor;
31/**
32 * IR representation of an indexed access (brackets operator.)
33 */
34@Immutable
35public final class IndexNode extends BaseNode {
36    private static final long serialVersionUID = 1L;
37
38    /** Property index. */
39    private final Expression index;
40
41    /**
42     * Constructors
43     *
44     * @param token   token
45     * @param finish  finish
46     * @param base    base node for access
47     * @param index   index for access
48     */
49    public IndexNode(final long token, final int finish, final Expression base, final Expression index) {
50        super(token, finish, base, false);
51        this.index = index;
52    }
53
54    private IndexNode(final IndexNode indexNode, final Expression base, final Expression index, final boolean isFunction, final Type type, final int programPoint) {
55        super(indexNode, base, isFunction, type, programPoint);
56        this.index = index;
57    }
58
59    @Override
60    public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
61        if (visitor.enterIndexNode(this)) {
62            return visitor.leaveIndexNode(
63                setBase((Expression)base.accept(visitor)).
64                setIndex((Expression)index.accept(visitor)));
65        }
66        return this;
67    }
68
69    @Override
70    public void toString(final StringBuilder sb, final boolean printType) {
71        final boolean needsParen = tokenType().needsParens(base.tokenType(), true);
72
73        if (needsParen) {
74            sb.append('(');
75        }
76
77        if (printType) {
78            optimisticTypeToString(sb);
79        }
80
81        base.toString(sb, printType);
82
83        if (needsParen) {
84            sb.append(')');
85        }
86
87        sb.append('[');
88        index.toString(sb, printType);
89        sb.append(']');
90    }
91
92    /**
93     * Get the index expression for this IndexNode
94     * @return the index
95     */
96    public Expression getIndex() {
97        return index;
98    }
99
100    private IndexNode setBase(final Expression base) {
101        if (this.base == base) {
102            return this;
103        }
104        return new IndexNode(this, base, index, isFunction(), type, programPoint);
105    }
106
107    /**
108     * Set the index expression for this node
109     * @param index new index expression
110     * @return a node equivalent to this one except for the requested change.
111     */
112    public IndexNode setIndex(final Expression index) {
113        if(this.index == index) {
114            return this;
115        }
116        return new IndexNode(this, base, index, isFunction(), type, programPoint);
117    }
118
119    @Override
120    public IndexNode setType(final Type type) {
121        if (this.type == type) {
122            return this;
123        }
124        return new IndexNode(this, base, index, isFunction(), type, programPoint);
125    }
126
127    @Override
128    public IndexNode setIsFunction() {
129        if (isFunction()) {
130            return this;
131        }
132        return new IndexNode(this, base, index, true, type, programPoint);
133    }
134
135    @Override
136    public IndexNode setProgramPoint(final int programPoint) {
137        if (this.programPoint == programPoint) {
138            return this;
139        }
140        return new IndexNode(this, base, index, isFunction(), type, programPoint);
141    }
142}
143