/
JavaRecursiveElementVisitor.java
58 lines (53 loc) · 2.05 KB
/
JavaRecursiveElementVisitor.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
/*
* Copyright 2000-2015 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* @author max
*/
package com.intellij.psi;
import com.intellij.util.containers.Stack;
import org.jetbrains.annotations.NotNull;
/**
* a JavaElementVisitor which also visits all children elements
* in a tree pre-order, see <a href="https://en.wikipedia.org/wiki/Tree_traversal#Pre-order">Tree traversal:Pre-order</a> for details.
* <p>
* <b>Note</b>: This visitor handles all elements recursively, so it can consume a large amount of stack space for very deep trees.
* For such deep trees please consider using {@link JavaRecursiveElementWalkingVisitor} instead.
*/
public abstract class JavaRecursiveElementVisitor extends JavaElementVisitor implements PsiRecursiveVisitor {
// This stack thing is intended to prevent exponential child traversing due to visitReferenceExpression calls both visitRefElement
// and visitExpression.
private final Stack<PsiReferenceExpression> myRefExprsInVisit = new Stack<>();
@Override
public void visitElement(@NotNull PsiElement element) {
if (!myRefExprsInVisit.isEmpty() && myRefExprsInVisit.peek() == element) {
myRefExprsInVisit.pop();
myRefExprsInVisit.push(null);
}
else {
element.acceptChildren(this);
}
}
@Override public void visitReferenceExpression(@NotNull PsiReferenceExpression expression) {
myRefExprsInVisit.push(expression);
try {
visitExpression(expression);
visitReferenceElement(expression);
}
finally {
myRefExprsInVisit.pop();
}
}
}