KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > codehaus > groovy > antlr > AntlrASTProcessSnippets


1 /**
2  *
3  * Copyright 2005 Jeremy Rayner
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  **/
18
19 package org.codehaus.groovy.antlr;
20
21 /**
22  * Process to decorate antlr AST with ending line/col info, and if
23  * possible the snipppet of source from the start/end line/col for each node.
24  *
25  * @author <a HREF="mailto:groovy@ross-rayner.com">Jeremy Rayner</a>
26  * @version $Revision: 1.1 $
27  */
28
29 import antlr.collections.AST;
30 import java.util.*;
31
32 public class AntlrASTProcessSnippets implements AntlrASTProcessor{
33     private SourceBuffer sourceBuffer;
34
35     public AntlrASTProcessSnippets(SourceBuffer sourceBuffer) {
36         this.sourceBuffer = sourceBuffer;
37     }
38
39     /**
40      * decorate antlr AST with ending line/col info, and if
41      * possible the snipppet of source from the start/end line/col for each node.
42      * @param t the AST to decorate
43      * @return the decorated AST
44      */
45     public AST process(AST t) {
46         // first visit
47 List l = new ArrayList();
48         t = traverse((GroovySourceAST)t,l,null);
49
50         //System.out.println("l:" + l);
51 // second visit
52 Iterator itr = l.iterator();
53         if (itr.hasNext()) { itr.next(); /* discard first */ }
54         t = traverse((GroovySourceAST)t,null,itr);
55         return t;
56     }
57
58     /**
59      * traverse an AST node
60      * @param t the AST node to traverse
61      * @param l A list to add line/col info to
62      * @param itr An iterator over a list of line/col
63      * @return A decorated AST node
64      */
65     private AST traverse(GroovySourceAST t,List l,Iterator itr) {
66         if (t == null) { return t; }
67
68         // first visit of node
69 if (l != null) {
70             l.add(new LineColumn(t.getLine(),t.getColumn()));
71         }
72
73         // second vist of node
74 if (itr != null && itr.hasNext()) {
75             LineColumn lc = (LineColumn)itr.next();
76             if (t.getLineLast() == 0) {
77                 int nextLine = lc.getLine();
78                 int nextColumn = lc.getColumn();
79                 if (nextLine < t.getLine() || (nextLine == t.getLine() && nextColumn < t.getColumn())) {
80                     nextLine = t.getLine();
81                     nextColumn = t.getColumn();
82                 }
83                 t.setLineLast(nextLine);
84                 t.setColumnLast(nextColumn);
85                 t.setSnippet(sourceBuffer.getSnippet(new LineColumn(t.getLine(),t.getColumn()),
86                                 new LineColumn(t.getLineLast(),t.getColumnLast())));
87             }
88         }
89
90         GroovySourceAST child = (GroovySourceAST)t.getFirstChild();
91         if (child != null) {
92             traverse(child,l,itr);
93         }
94
95         GroovySourceAST sibling = (GroovySourceAST)t.getNextSibling();
96         if (sibling != null) {
97             traverse(sibling,l,itr);
98         }
99
100         return t;
101     }
102 }
103
Popular Tags