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      1 /*
      2  * [The "BSD licence"]
      3  * Copyright (c) 2005-2008 Terence Parr
      4  * All rights reserved.
      5  *
      6  * Conversion to C#:
      7  * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
      8  * All rights reserved.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 namespace Antlr.Runtime.Tree {
     34 
     35     /** <summary>A node representing erroneous token range in token stream</summary> */
     36     [System.Serializable]
     37     public class CommonErrorNode : CommonTree {
     38         public IIntStream input;
     39         public IToken start;
     40         public IToken stop;
     41         public RecognitionException trappedException;
     42 
     43         public CommonErrorNode(ITokenStream input, IToken start, IToken stop,
     44                                RecognitionException e) {
     45             //System.out.println("start: "+start+", stop: "+stop);
     46             if (stop == null ||
     47                  (stop.TokenIndex < start.TokenIndex &&
     48                   stop.Type != TokenTypes.EndOfFile)) {
     49                 // sometimes resync does not consume a token (when LT(1) is
     50                 // in follow set.  So, stop will be 1 to left to start. adjust.
     51                 // Also handle case where start is the first token and no token
     52                 // is consumed during recovery; LT(-1) will return null.
     53                 stop = start;
     54             }
     55             this.input = input;
     56             this.start = start;
     57             this.stop = stop;
     58             this.trappedException = e;
     59         }
     60 
     61         #region Properties
     62         public override bool IsNil {
     63             get {
     64                 return false;
     65             }
     66         }
     67         public override string Text {
     68             get {
     69                 string badText = null;
     70                 if (start is IToken) {
     71                     int i = ((IToken)start).TokenIndex;
     72                     int j = ((IToken)stop).TokenIndex;
     73                     if (((IToken)stop).Type == TokenTypes.EndOfFile) {
     74                         j = ((ITokenStream)input).Count;
     75                     }
     76                     badText = ((ITokenStream)input).ToString(i, j);
     77                 } else if (start is ITree) {
     78                     badText = ((ITreeNodeStream)input).ToString(start, stop);
     79                 } else {
     80                     // people should subclass if they alter the tree type so this
     81                     // next one is for sure correct.
     82                     badText = "<unknown>";
     83                 }
     84                 return badText;
     85             }
     86             set {
     87             }
     88         }
     89         public override int Type {
     90             get {
     91                 return TokenTypes.Invalid;
     92             }
     93             set {
     94             }
     95         }
     96         #endregion
     97 
     98         public override string ToString() {
     99             if (trappedException is MissingTokenException) {
    100                 return "<missing type: " +
    101                        ((MissingTokenException)trappedException).MissingType +
    102                        ">";
    103             } else if (trappedException is UnwantedTokenException) {
    104                 return "<extraneous: " +
    105                        ((UnwantedTokenException)trappedException).UnexpectedToken +
    106                        ", resync=" + Text + ">";
    107             } else if (trappedException is MismatchedTokenException) {
    108                 return "<mismatched token: " + trappedException.Token + ", resync=" + Text + ">";
    109             } else if (trappedException is NoViableAltException) {
    110                 return "<unexpected: " + trappedException.Token +
    111                        ", resync=" + Text + ">";
    112             }
    113             return "<error: " + Text + ">";
    114         }
    115     }
    116 }
    117