001    /**
002     *
003     * Copyright 2005 Jeremy Rayner
004     *
005     * Licensed under the Apache License, Version 2.0 (the "License");
006     * you may not use this file except in compliance with the License.
007     * You may obtain a copy of the License at
008     *
009     * http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     *
017     **/
018    
019    package org.codehaus.groovy.antlr;
020    
021    /**
022     * Process to decorate antlr AST with ending line/col info, and if
023     * possible the snipppet of source from the start/end line/col for each node.
024     *
025     * @author <a href="mailto:groovy@ross-rayner.com">Jeremy Rayner</a>
026     * @version $Revision: 1.1 $
027     */
028    
029    import antlr.collections.AST;
030    import java.util.*;
031    
032    public class AntlrASTProcessSnippets implements AntlrASTProcessor{
033        private SourceBuffer sourceBuffer;
034    
035        public AntlrASTProcessSnippets(SourceBuffer sourceBuffer) {
036            this.sourceBuffer = sourceBuffer;
037        }
038    
039        /**
040         * decorate antlr AST with ending line/col info, and if
041         * possible the snipppet of source from the start/end line/col for each node.
042         * @param t the AST to decorate
043         * @return the decorated AST
044         */
045        public AST process(AST t) {
046            // first visit
047            List l = new ArrayList();
048            t = traverse((GroovySourceAST)t,l,null);
049    
050            //System.out.println("l:" + l);
051            // second visit
052            Iterator itr = l.iterator();
053            if (itr.hasNext()) { itr.next(); /* discard first */ }
054            t = traverse((GroovySourceAST)t,null,itr);
055            return t;
056        }
057    
058        /**
059         * traverse an AST node
060         * @param t the AST node to traverse
061         * @param l A list to add line/col info to
062         * @param itr An iterator over a list of line/col
063         * @return A decorated AST node
064         */
065        private AST traverse(GroovySourceAST t,List l,Iterator itr) {
066            if (t == null) { return t; }
067    
068            // first visit of node
069            if (l != null) {
070                l.add(new LineColumn(t.getLine(),t.getColumn()));
071            }
072    
073            // second vist of node
074            if (itr != null && itr.hasNext()) {
075                LineColumn lc = (LineColumn)itr.next();
076                if (t.getLineLast() == 0) {
077                    int nextLine = lc.getLine();
078                    int nextColumn = lc.getColumn();
079                    if (nextLine < t.getLine() || (nextLine == t.getLine() && nextColumn < t.getColumn())) {
080                        nextLine = t.getLine();
081                        nextColumn = t.getColumn();
082                    }
083                    t.setLineLast(nextLine);
084                    t.setColumnLast(nextColumn);
085                    t.setSnippet(sourceBuffer.getSnippet(new LineColumn(t.getLine(),t.getColumn()),
086                                    new LineColumn(t.getLineLast(),t.getColumnLast())));
087                }
088            }
089    
090            GroovySourceAST child = (GroovySourceAST)t.getFirstChild();
091            if (child != null) {
092                traverse(child,l,itr);
093            }
094    
095            GroovySourceAST sibling = (GroovySourceAST)t.getNextSibling();
096            if (sibling != null) {
097                traverse(sibling,l,itr);
098            }
099    
100            return t;
101        }
102    }