antlr/runtime/CSharp/Antlr4.Runtime/RecognitionException.cs

/*
 * [The "BSD license"]
 *  Copyright (c) 2013 Terence Parr
 *  Copyright (c) 2013 Sam Harwell
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using Antlr4.Runtime;
using Antlr4.Runtime.Misc;
using Sharpen;

namespace Antlr4.Runtime
{
    /// <summary>The root of the ANTLR exception hierarchy.</summary>
    /// <remarks>
    /// The root of the ANTLR exception hierarchy. In general, ANTLR tracks just
    /// 3 kinds of errors: prediction errors, failed predicate errors, and
    /// mismatched input errors. In each case, the parser knows where it is
    /// in the input, where it is in the ATN, the rule invocation stack,
    /// and what kind of problem occurred.
    /// </remarks>
    [System.Serializable]
    public class RecognitionException : Exception
    {
        private const long serialVersionUID = -3861826954750022374L;

        /// <summary>Who threw the exception?</summary>
        private IRecognizer recognizer;

        private RuleContext ctx;

        private IIntStream input;

        /// <summary>The current Token when an error occurred.</summary>
        /// <remarks>
        /// The current Token when an error occurred.  Since not all streams
        /// can retrieve the ith Token, we have to track the Token object.
        /// For parsers.  Even when it's a tree parser, token might be set.
        /// </remarks>
        private IToken offendingToken;

        private int offendingState;

        public RecognitionException(Lexer lexer, ICharStream input)
        {
            // TODO: make a dummy recognizer for the interpreter to use?
            // Next two (ctx,input) should be what is in recognizer, but
            // won't work when interpreting
            this.recognizer = lexer;
            this.input = input;
        }

        public RecognitionException(IRecognizer recognizer, 
            IIntStream input, ParserRuleContext ctx)
        {
            this.recognizer = recognizer;
            this.input = input;
            this.ctx = ctx;
            if (recognizer != null)
            {
                this.offendingState = recognizer.State;
            }
        }

        public RecognitionException(string message, IRecognizer recognizer, IIntStream input, ParserRuleContext ctx) : base(message)
        {
            this.recognizer = recognizer;
            this.input = input;
            this.ctx = ctx;
            if (recognizer != null)
            {
                this.offendingState = recognizer.State;
            }
        }

        /// <summary>
        /// Where was the parser in the ATN when the error occurred?
        /// For No viable alternative exceptions, this is the decision state number.
        /// </summary>
        /// <remarks>
        /// Where was the parser in the ATN when the error occurred?
        /// For No viable alternative exceptions, this is the decision state number.
        /// For others, it is the state whose emanating edge we couldn't match.
        /// This will help us tie into the grammar and syntax diagrams in
        /// ANTLRWorks v2.
        /// </remarks>
        public int OffendingState
        {
            get
            {
                return offendingState;
            }
            protected set
            {
                int offendingState = value;
                this.offendingState = offendingState;
            }
        }

        public virtual IntervalSet GetExpectedTokens()
        {
            // TODO: do we really need this type check?
            if (recognizer is Parser)
            {
                return ((Parser)recognizer).GetExpectedTokens();
            }
            return null;
        }

        public virtual RuleContext Context
        {
            get
            {
                return ctx;
            }
        }

        public virtual IIntStream InputStream
        {
            get
            {
                return input;
            }
        }

        public IToken OffendingToken
        {
            get
            {
                return offendingToken;
            }
            protected set
            {
                IToken offendingToken = value;
                this.offendingToken = offendingToken;
            }
        }

        public virtual IRecognizer Recognizer
        {
            get
            {
                return recognizer;
            }
        }
    }
}