1/*
2 [The "BSD license"]
3 Copyright (c) 2005-2009 Terence Parr
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions
8 are met:
9 1. Redistributions of source code must retain the above copyright
10     notice, this list of conditions and the following disclaimer.
11 2. Redistributions in binary form must reproduce the above copyright
12     notice, this list of conditions and the following disclaimer in the
13     documentation and/or other materials provided with the distribution.
14 3. The name of the author may not be used to endorse or promote products
15     derived from this software without specific prior written permission.
16
17 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28package org.antlr.runtime.tree;
29
30import org.antlr.runtime.*;
31
32/** A node representing erroneous token range in token stream */
33public class CommonErrorNode extends CommonTree {
34	public IntStream input;
35	public Token start;
36	public Token stop;
37	public RecognitionException trappedException;
38
39	public CommonErrorNode(TokenStream input, Token start, Token stop,
40						   RecognitionException e)
41	{
42		//System.out.println("start: "+start+", stop: "+stop);
43		if ( stop==null ||
44			 (stop.getTokenIndex() < start.getTokenIndex() &&
45			  stop.getType()!=Token.EOF) )
46		{
47			// sometimes resync does not consume a token (when LT(1) is
48			// in follow set.  So, stop will be 1 to left to start. adjust.
49			// Also handle case where start is the first token and no token
50			// is consumed during recovery; LT(-1) will return null.
51			stop = start;
52		}
53		this.input = input;
54		this.start = start;
55		this.stop = stop;
56		this.trappedException = e;
57	}
58
59	public boolean isNil() {
60		return false;
61	}
62
63	public int getType() {
64		return Token.INVALID_TOKEN_TYPE;
65	}
66
67	public String getText() {
68		String badText = null;
69		if ( start instanceof Token ) {
70			int i = ((Token)start).getTokenIndex();
71			int j = ((Token)stop).getTokenIndex();
72			if ( ((Token)stop).getType() == Token.EOF ) {
73				j = ((TokenStream)input).size();
74			}
75			badText = ((TokenStream)input).toString(i, j);
76		}
77		else if ( start instanceof Tree ) {
78			badText = ((TreeNodeStream)input).toString(start, stop);
79		}
80		else {
81			// people should subclass if they alter the tree type so this
82			// next one is for sure correct.
83			badText = "<unknown>";
84		}
85		return badText;
86	}
87
88	public String toString() {
89		if ( trappedException instanceof MissingTokenException ) {
90			return "<missing type: "+
91				   ((MissingTokenException)trappedException).getMissingType()+
92				   ">";
93		}
94		else if ( trappedException instanceof UnwantedTokenException ) {
95			return "<extraneous: "+
96				   ((UnwantedTokenException)trappedException).getUnexpectedToken()+
97				   ", resync="+getText()+">";
98		}
99		else if ( trappedException instanceof MismatchedTokenException ) {
100			return "<mismatched token: "+trappedException.token+", resync="+getText()+">";
101		}
102		else if ( trappedException instanceof NoViableAltException ) {
103			return "<unexpected: "+trappedException.token+
104				   ", resync="+getText()+">";
105		}
106		return "<error: "+getText()+">";
107	}
108}
109