Esempio n. 1
0
        public RecognitionException(string message, IIntStream input, int k, Exception innerException)
            : base(message, innerException)
        {
            this._input = input;
            this._k     = k;
            if (input != null)
            {
                this._index = input.Index + k - 1;
                if (input is ITokenStream)
                {
                    this._token = ((ITokenStream)input).LT(k);
                    this._line  = _token.Line;
                    this._charPositionInLine = _token.CharPositionInLine;
                }

                ITreeNodeStream tns = input as ITreeNodeStream;
                if (tns != null)
                {
                    ExtractInformationFromTreeNodeStream(tns, k);
                }
                else
                {
                    ICharStream charStream = input as ICharStream;
                    if (charStream != null)
                    {
                        int mark = input.Mark();
                        try
                        {
                            for (int i = 0; i < k - 1; i++)
                            {
                                input.Consume();
                            }

                            this._c    = input.LA(1);
                            this._line = ((ICharStream)input).Line;
                            this._charPositionInLine = ((ICharStream)input).CharPositionInLine;
                        }
                        finally
                        {
                            input.Rewind(mark);
                        }
                    }
                    else
                    {
                        this._c = input.LA(k);
                    }
                }
            }
        }
Esempio n. 2
0
 public virtual int Predict(IIntStream input)
 {
     int num6;
     if (this.debug)
     {
         Console.Error.WriteLine("Enter DFA.predict for decision " + this.decisionNumber);
     }
     int marker = input.Mark();
     int index = 0;
     try
     {
     Label_0030:
         if (this.debug)
         {
             Console.Error.WriteLine(string.Concat(new object[] { "DFA ", this.decisionNumber, " state ", index, " LA(1)=", (char) input.LA(1), "(", input.LA(1), "), index=", input.Index }));
         }
         int s = this.special[index];
         if (s >= 0)
         {
             if (this.debug)
             {
                 Console.Error.WriteLine(string.Concat(new object[] { "DFA ", this.decisionNumber, " state ", index, " is special state ", s }));
             }
             index = this.SpecialStateTransition(this, s, input);
             if (this.debug)
             {
                 Console.Error.WriteLine(string.Concat(new object[] { "DFA ", this.decisionNumber, " returns from special state ", s, " to ", index }));
             }
             if (index == -1)
             {
                 this.NoViableAlt(index, input);
                 return 0;
             }
             input.Consume();
             goto Label_0030;
         }
         if (this.accept[index] >= 1)
         {
             if (this.debug)
             {
                 Console.Error.WriteLine(string.Concat(new object[] { "accept; predict ", this.accept[index], " from state ", index }));
             }
             return this.accept[index];
         }
         char ch = (char) input.LA(1);
         if ((ch >= this.min[index]) && (ch <= this.max[index]))
         {
             int num4 = this.transition[index][ch - this.min[index]];
             if (num4 < 0)
             {
                 if (this.eot[index] < 0)
                 {
                     this.NoViableAlt(index, input);
                     return 0;
                 }
                 if (this.debug)
                 {
                     Console.Error.WriteLine("EOT transition");
                 }
                 index = this.eot[index];
                 input.Consume();
             }
             else
             {
                 index = num4;
                 input.Consume();
             }
             goto Label_0030;
         }
         if (this.eot[index] >= 0)
         {
             if (this.debug)
             {
                 Console.Error.WriteLine("EOT transition");
             }
             index = this.eot[index];
             input.Consume();
             goto Label_0030;
         }
         if ((ch == 0xffff) && (this.eof[index] >= 0))
         {
             if (this.debug)
             {
                 Console.Error.WriteLine(string.Concat(new object[] { "accept via EOF; predict ", this.accept[this.eof[index]], " from ", this.eof[index] }));
             }
             return this.accept[this.eof[index]];
         }
         if (this.debug)
         {
             Console.Error.WriteLine(string.Concat(new object[] { "min[", index, "]=", this.min[index] }));
             Console.Error.WriteLine(string.Concat(new object[] { "max[", index, "]=", this.max[index] }));
             Console.Error.WriteLine(string.Concat(new object[] { "eot[", index, "]=", this.eot[index] }));
             Console.Error.WriteLine(string.Concat(new object[] { "eof[", index, "]=", this.eof[index] }));
             for (int i = 0; i < this.transition[index].Length; i++)
             {
                 Console.Error.Write(this.transition[index][i] + " ");
             }
             Console.Error.WriteLine();
         }
         this.NoViableAlt(index, input);
         num6 = 0;
     }
     finally
     {
         input.Rewind(marker);
     }
     return num6;
 }
Esempio n. 3
0
        /** <summary>
         *  From the input stream, predict what alternative will succeed
         *  using this DFA (representing the covering regular approximation
         *  to the underlying CFL).  Return an alternative number 1..n.  Throw
         *  an exception upon error.
         *  </summary>
         */
        public virtual int Predict(IIntStream input)
        {
            if (debug)
            {
                Console.Error.WriteLine("Enter DFA.predict for decision " + decisionNumber);
            }
            int mark = input.Mark(); // remember where decision started in input
            int s    = 0;            // we always start at s0

            try
            {
                for ( ; ;)
                {
                    if (debug)
                    {
                        Console.Error.WriteLine("DFA " + decisionNumber + " state " + s + " LA(1)=" + (char)input.LA(1) + "(" + input.LA(1) +
                                                "), index=" + input.Index);
                    }
                    int specialState = special[s];
                    if (specialState >= 0)
                    {
                        if (debug)
                        {
                            Console.Error.WriteLine("DFA " + decisionNumber +
                                                    " state " + s + " is special state " + specialState);
                        }
                        s = SpecialStateTransition(this, specialState, input);
                        if (debug)
                        {
                            Console.Error.WriteLine("DFA " + decisionNumber +
                                                    " returns from special state " + specialState + " to " + s);
                        }
                        if (s == -1)
                        {
                            NoViableAlt(s, input);
                            return(0);
                        }
                        input.Consume();
                        continue;
                    }
                    if (accept[s] >= 1)
                    {
                        if (debug)
                        {
                            Console.Error.WriteLine("accept; predict " + accept[s] + " from state " + s);
                        }
                        return(accept[s]);
                    }
                    // look for a normal char transition
                    char c = (char)input.LA(1);   // -1 == \uFFFF, all tokens fit in 65000 space
                    if (c >= min[s] && c <= max[s])
                    {
                        int snext = transition[s][c - min[s]]; // move to next state
                        if (snext < 0)
                        {
                            // was in range but not a normal transition
                            // must check EOT, which is like the else clause.
                            // eot[s]>=0 indicates that an EOT edge goes to another
                            // state.
                            if (eot[s] >= 0)
                            {  // EOT Transition to accept state?
                                if (debug)
                                {
                                    Console.Error.WriteLine("EOT transition");
                                }
                                s = eot[s];
                                input.Consume();
                                // TODO: I had this as return accept[eot[s]]
                                // which assumed here that the EOT edge always
                                // went to an accept...faster to do this, but
                                // what about predicated edges coming from EOT
                                // target?
                                continue;
                            }
                            NoViableAlt(s, input);
                            return(0);
                        }
                        s = snext;
                        input.Consume();
                        continue;
                    }
                    if (eot[s] >= 0)
                    {  // EOT Transition?
                        if (debug)
                        {
                            Console.Error.WriteLine("EOT transition");
                        }
                        s = eot[s];
                        input.Consume();
                        continue;
                    }
                    if (c == unchecked ((char)TokenTypes.EndOfFile) && eof[s] >= 0)
                    {  // EOF Transition to accept state?
                        if (debug)
                        {
                            Console.Error.WriteLine("accept via EOF; predict " + accept[eof[s]] + " from " + eof[s]);
                        }
                        return(accept[eof[s]]);
                    }
                    // not in range and not EOF/EOT, must be invalid symbol
                    if (debug)
                    {
                        Console.Error.WriteLine("min[" + s + "]=" + min[s]);
                        Console.Error.WriteLine("max[" + s + "]=" + max[s]);
                        Console.Error.WriteLine("eot[" + s + "]=" + eot[s]);
                        Console.Error.WriteLine("eof[" + s + "]=" + eof[s]);
                        for (int p = 0; p < transition[s].Length; p++)
                        {
                            Console.Error.Write(transition[s][p] + " ");
                        }
                        Console.Error.WriteLine();
                    }
                    NoViableAlt(s, input);
                    return(0);
                }
            }
            finally
            {
                input.Rewind(mark);
            }
        }
Esempio n. 4
0
        public RecognitionException(string message, IIntStream input, int k, Exception innerException)
            : base(message, innerException)
        {
            this._input = input;
            this._k = k;
            if (input != null)
            {
                this._index = input.Index + k - 1;
                if (input is ITokenStream)
                {
                    this._token = ((ITokenStream)input).LT(k);
                    this._line = _token.Line;
                    this._charPositionInLine = _token.CharPositionInLine;
                }

                ITreeNodeStream tns = input as ITreeNodeStream;
                if (tns != null)
                {
                    ExtractInformationFromTreeNodeStream(tns, k);
                }
                else
                {
                    ICharStream charStream = input as ICharStream;
                    if (charStream != null)
                    {
                        int mark = input.Mark();
                        try
                        {
                            for (int i = 0; i < k - 1; i++)
                                input.Consume();

                            this._c = input.LA(1);
                            this._line = ((ICharStream)input).Line;
                            this._charPositionInLine = ((ICharStream)input).CharPositionInLine;
                        }
                        finally
                        {
                            input.Rewind(mark);
                        }
                    }
                    else
                    {
                        this._c = input.LA(k);
                    }
                }
            }
        }
Esempio n. 5
0
File: DFA.cs Progetto: ksmyth/antlr
 /** <summary>
  *  From the input stream, predict what alternative will succeed
  *  using this DFA (representing the covering regular approximation
  *  to the underlying CFL).  Return an alternative number 1..n.  Throw
  *  an exception upon error.
  *  </summary>
  */
 public virtual int Predict( IIntStream input )
 {
     if ( debug )
     {
         Console.Error.WriteLine( "Enter DFA.predict for decision " + decisionNumber );
     }
     int mark = input.Mark(); // remember where decision started in input
     int s = 0; // we always start at s0
     try
     {
         for ( ; ; )
         {
             if ( debug )
                 Console.Error.WriteLine( "DFA " + decisionNumber + " state " + s + " LA(1)=" + (char)input.LA( 1 ) + "(" + input.LA( 1 ) +
                                    "), index=" + input.Index );
             int specialState = special[s];
             if ( specialState >= 0 )
             {
                 if ( debug )
                 {
                     Console.Error.WriteLine( "DFA " + decisionNumber +
                         " state " + s + " is special state " + specialState );
                 }
                 s = SpecialStateTransition( this, specialState, input );
                 if ( debug )
                 {
                     Console.Error.WriteLine( "DFA " + decisionNumber +
                         " returns from special state " + specialState + " to " + s );
                 }
                 if ( s == -1 )
                 {
                     NoViableAlt( s, input );
                     return 0;
                 }
                 input.Consume();
                 continue;
             }
             if ( accept[s] >= 1 )
             {
                 if ( debug )
                     Console.Error.WriteLine( "accept; predict " + accept[s] + " from state " + s );
                 return accept[s];
             }
             // look for a normal char transition
             char c = (char)input.LA( 1 ); // -1 == \uFFFF, all tokens fit in 65000 space
             if ( c >= min[s] && c <= max[s] )
             {
                 int snext = transition[s][c - min[s]]; // move to next state
                 if ( snext < 0 )
                 {
                     // was in range but not a normal transition
                     // must check EOT, which is like the else clause.
                     // eot[s]>=0 indicates that an EOT edge goes to another
                     // state.
                     if ( eot[s] >= 0 )
                     {  // EOT Transition to accept state?
                         if ( debug )
                             Console.Error.WriteLine( "EOT transition" );
                         s = eot[s];
                         input.Consume();
                         // TODO: I had this as return accept[eot[s]]
                         // which assumed here that the EOT edge always
                         // went to an accept...faster to do this, but
                         // what about predicated edges coming from EOT
                         // target?
                         continue;
                     }
                     NoViableAlt( s, input );
                     return 0;
                 }
                 s = snext;
                 input.Consume();
                 continue;
             }
             if ( eot[s] >= 0 )
             {  // EOT Transition?
                 if ( debug )
                     Console.Error.WriteLine( "EOT transition" );
                 s = eot[s];
                 input.Consume();
                 continue;
             }
             if ( c == unchecked((char)TokenConstants.EOF) && eof[s] >= 0 )
             {  // EOF Transition to accept state?
                 if ( debug )
                     Console.Error.WriteLine( "accept via EOF; predict " + accept[eof[s]] + " from " + eof[s] );
                 return accept[eof[s]];
             }
             // not in range and not EOF/EOT, must be invalid symbol
             if ( debug )
             {
                 Console.Error.WriteLine( "min[" + s + "]=" + min[s] );
                 Console.Error.WriteLine( "max[" + s + "]=" + max[s] );
                 Console.Error.WriteLine( "eot[" + s + "]=" + eot[s] );
                 Console.Error.WriteLine( "eof[" + s + "]=" + eof[s] );
                 for ( int p = 0; p < transition[s].Length; p++ )
                 {
                     Console.Error.Write( transition[s][p] + " " );
                 }
                 Console.Error.WriteLine();
             }
             NoViableAlt( s, input );
             return 0;
         }
     }
     finally
     {
         input.Rewind( mark );
     }
 }
Esempio n. 6
0
        /** <summary>
         *  From the input stream, predict what alternative will succeed
         *  using this DFA (representing the covering regular approximation
         *  to the underlying CFL).  Return an alternative number 1..n.  Throw
         *  an exception upon error.
         *  </summary>
         */
        public virtual int Predict(IIntStream input)
        {
            if (input == null)
            {
                throw new ArgumentNullException("input");
            }

            DfaDebugMessage("Enter DFA.Predict for decision {0}", decisionNumber);

            int mark = input.Mark(); // remember where decision started in input
            int s    = 0;            // we always start at s0

            try
            {
                while (true)
                {
                    DfaDebugMessage("DFA {0} state {1} LA(1)={2}({3}), index={4}", decisionNumber, s, (char)input.LA(1), input.LA(1), input.Index);

                    int specialState = special[s];
                    if (specialState >= 0)
                    {
                        DfaDebugMessage("DFA {0} state {1} is special state {2}", decisionNumber, s, specialState);

                        s = SpecialStateTransition(this, specialState, input);

                        DfaDebugMessage("DFA {0} returns from special state {1} to {2}", decisionNumber, specialState, s);

                        if (s == -1)
                        {
                            NoViableAlt(s, input);
                            return(0);
                        }

                        input.Consume();
                        continue;
                    }

                    if (accept[s] >= 1)
                    {
                        DfaDebugMessage("accept; predict {0} from state {1}", accept[s], s);
                        return(accept[s]);
                    }

                    // look for a normal char transition
                    char c = (char)input.LA(1);   // -1 == \uFFFF, all tokens fit in 65000 space
                    if (c >= min[s] && c <= max[s])
                    {
                        int snext = transition[s][c - min[s]]; // move to next state
                        if (snext < 0)
                        {
                            // was in range but not a normal transition
                            // must check EOT, which is like the else clause.
                            // eot[s]>=0 indicates that an EOT edge goes to another
                            // state.
                            if (eot[s] >= 0)
                            {
                                // EOT Transition to accept state?
                                DfaDebugMessage("EOT transition");
                                s = eot[s];
                                input.Consume();
                                // TODO: I had this as return accept[eot[s]]
                                // which assumed here that the EOT edge always
                                // went to an accept...faster to do this, but
                                // what about predicated edges coming from EOT
                                // target?
                                continue;
                            }

                            NoViableAlt(s, input);
                            return(0);
                        }

                        s = snext;
                        input.Consume();
                        continue;
                    }

                    if (eot[s] >= 0)
                    {
                        // EOT Transition?
                        DfaDebugMessage("EOT transition");
                        s = eot[s];
                        input.Consume();
                        continue;
                    }

                    if (c == unchecked ((char)TokenTypes.EndOfFile) && eof[s] >= 0)
                    {
                        // EOF Transition to accept state?
                        DfaDebugMessage("accept via EOF; predict {0} from {1}", accept[eof[s]], eof[s]);
                        return(accept[eof[s]]);
                    }

                    // not in range and not EOF/EOT, must be invalid symbol
                    DfaDebugInvalidSymbol(s);

                    NoViableAlt(s, input);
                    return(0);
                }
            }
            finally
            {
                input.Rewind(mark);
            }
        }
Esempio n. 7
0
        /** Fill a list of all NFA states visited during the parse */
        protected virtual void ParseEngine(string startRule,
                                           NFAState start,
                                           NFAState stop,
                                           IIntStream input,
                                           Stack <object> ruleInvocationStack,
                                           IDebugEventListener actions,
                                           IList <NFAState> visitedStates)
        {
            NFAState s = start;

            if (actions != null)
            {
                actions.EnterRule(s.nfa.Grammar.FileName, start.enclosingRule.Name);
            }
            int t = input.LA(1);

            while (s != stop)
            {
                if (visitedStates != null)
                {
                    visitedStates.Add(s);
                }
                //Console.Out.WriteLine( "parse state " + s.stateNumber + " input=" + s.nfa.Grammar.getTokenDisplayName( t ) );
                // CASE 1: decision state
                if (s.DecisionNumber > 0 && s.nfa.Grammar.GetNumberOfAltsForDecisionNFA(s) > 1)
                {
                    // decision point, must predict and jump to alt
                    DFA dfa = s.nfa.Grammar.GetLookaheadDFA(s.DecisionNumber);
                    //if ( s.nfa.Grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "decision: " +
                    //                   dfa.getNFADecisionStartState().Description +
                    //                   " input=" + s.nfa.Grammar.getTokenDisplayName( t ) );
                    //}
                    int m            = input.Mark();
                    int predictedAlt = Predict(dfa);
                    if (predictedAlt == NFA.INVALID_ALT_NUMBER)
                    {
                        string description        = dfa.NFADecisionStartState.Description;
                        NoViableAltException nvae =
                            new NoViableAltException(description,
                                                     dfa.NfaStartStateDecisionNumber,
                                                     s.StateNumber,
                                                     input);
                        if (actions != null)
                        {
                            actions.RecognitionException(nvae);
                        }
                        input.Consume(); // recover
                        throw nvae;
                    }
                    input.Rewind(m);
                    int parseAlt =
                        s.TranslateDisplayAltToWalkAlt(predictedAlt);
                    //if ( s.nfa.Grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "predicted alt " + predictedAlt + ", parseAlt " + parseAlt );
                    //}
                    NFAState alt;
                    if (parseAlt > s.nfa.Grammar.GetNumberOfAltsForDecisionNFA(s))
                    {
                        // implied branch of loop etc...
                        alt = s.nfa.Grammar.nfa.GetState(s.endOfBlockStateNumber);
                    }
                    else
                    {
                        alt = s.nfa.Grammar.GetNFAStateForAltOfDecision(s, parseAlt);
                    }
                    s = (NFAState)alt.transition[0].Target;
                    continue;
                }

                // CASE 2: finished matching a rule
                if (s.IsAcceptState)
                { // end of rule node
                    if (actions != null)
                    {
                        actions.ExitRule(s.nfa.Grammar.FileName, s.enclosingRule.Name);
                    }
                    if (ruleInvocationStack.Count == 0)
                    {
                        // done parsing.  Hit the start state.
                        //Console.Out.WriteLine( "stack empty in stop state for " + s.enclosingRule );
                        break;
                    }
                    // pop invoking state off the stack to know where to return to
                    NFAState invokingState = (NFAState)ruleInvocationStack.Pop();
                    RuleClosureTransition invokingTransition =
                        (RuleClosureTransition)invokingState.transition[0];
                    // move to node after state that invoked this rule
                    s = invokingTransition.FollowState;
                    continue;
                }

                Transition trans = s.transition[0];
                Label      label = trans.Label;
                if (label.IsSemanticPredicate)
                {
                    FailedPredicateException fpe =
                        new FailedPredicateException(input,
                                                     s.enclosingRule.Name,
                                                     "can't deal with predicates yet");
                    if (actions != null)
                    {
                        actions.RecognitionException(fpe);
                    }
                }

                // CASE 3: epsilon transition
                if (label.IsEpsilon)
                {
                    // CASE 3a: rule invocation state
                    if (trans is RuleClosureTransition)
                    {
                        ruleInvocationStack.Push(s);
                        s = (NFAState)trans.Target;
                        //Console.Out.WriteLine( "call " + s.enclosingRule.name + " from " + s.nfa.Grammar.getFileName() );
                        if (actions != null)
                        {
                            actions.EnterRule(s.nfa.Grammar.FileName, s.enclosingRule.Name);
                        }
                        // could be jumping to new grammar, make sure DFA created
                        if (!s.nfa.Grammar.AllDecisionDFAHaveBeenCreated)
                        {
                            s.nfa.Grammar.CreateLookaheadDFAs();
                        }
                    }
                    // CASE 3b: plain old epsilon transition, just move
                    else
                    {
                        s = (NFAState)trans.Target;
                    }
                }

                // CASE 4: match label on transition
                else if (label.Matches(t))
                {
                    if (actions != null)
                    {
                        if (s.nfa.Grammar.type == GrammarType.Parser ||
                            s.nfa.Grammar.type == GrammarType.Combined)
                        {
                            actions.ConsumeToken(((ITokenStream)input).LT(1));
                        }
                    }
                    s = (NFAState)s.transition[0].Target;
                    input.Consume();
                    t = input.LA(1);
                }

                // CASE 5: error condition; label is inconsistent with input
                else
                {
                    if (label.IsAtom)
                    {
                        MismatchedTokenException mte =
                            new MismatchedTokenException(label.Atom, input);
                        if (actions != null)
                        {
                            actions.RecognitionException(mte);
                        }
                        input.Consume(); // recover
                        throw mte;
                    }
                    else if (label.IsSet)
                    {
                        MismatchedSetException mse =
                            new MismatchedSetException(((IntervalSet)label.Set).ToRuntimeBitSet(),
                                                       input);
                        if (actions != null)
                        {
                            actions.RecognitionException(mse);
                        }
                        input.Consume(); // recover
                        throw mse;
                    }
                    else if (label.IsSemanticPredicate)
                    {
                        FailedPredicateException fpe =
                            new FailedPredicateException(input,
                                                         s.enclosingRule.Name,
                                                         label.SemanticContext.ToString());
                        if (actions != null)
                        {
                            actions.RecognitionException(fpe);
                        }
                        input.Consume(); // recover
                        throw fpe;
                    }
                    else
                    {
                        throw new RecognitionException(input);   // unknown error
                    }
                }
            }
            //Console.Out.WriteLine( "hit stop state for " + stop.enclosingRule );
            if (actions != null)
            {
                actions.ExitRule(s.nfa.Grammar.FileName, stop.enclosingRule.Name);
            }
        }
Esempio n. 8
0
        /** <summary>
         *  From the input stream, predict what alternative will succeed
         *  using this DFA (representing the covering regular approximation
         *  to the underlying CFL).  Return an alternative number 1..n.  Throw
         *  an exception upon error.
         *  </summary>
         */
        public virtual int Predict( IIntStream input )
        {
            if (input == null)
                throw new ArgumentNullException("input");

            DfaDebugMessage("Enter DFA.Predict for decision {0}", decisionNumber);

            int mark = input.Mark(); // remember where decision started in input
            int s = 0; // we always start at s0
            try
            {
                while (true)
                {
                    DfaDebugMessage("DFA {0} state {1} LA(1)={2}({3}), index={4}", decisionNumber, s, (char)input.LA(1), input.LA(1), input.Index);

                    int specialState = special[s];
                    if ( specialState >= 0 )
                    {
                        DfaDebugMessage("DFA {0} state {1} is special state {2}", decisionNumber, s, specialState);

                        s = SpecialStateTransition( this, specialState, input );

                        DfaDebugMessage("DFA {0} returns from special state {1} to {2}", decisionNumber, specialState, s);

                        if ( s == -1 )
                        {
                            NoViableAlt( s, input );
                            return 0;
                        }

                        input.Consume();
                        continue;
                    }

                    if ( accept[s] >= 1 )
                    {
                        DfaDebugMessage("accept; predict {0} from state {1}", accept[s], s);
                        return accept[s];
                    }

                    // look for a normal char transition
                    char c = (char)input.LA( 1 ); // -1 == \uFFFF, all tokens fit in 65000 space
                    if ( c >= min[s] && c <= max[s] )
                    {
                        int snext = transition[s][c - min[s]]; // move to next state
                        if ( snext < 0 )
                        {
                            // was in range but not a normal transition
                            // must check EOT, which is like the else clause.
                            // eot[s]>=0 indicates that an EOT edge goes to another
                            // state.
                            if ( eot[s] >= 0 )
                            {
                                // EOT Transition to accept state?
                                DfaDebugMessage("EOT transition");
                                s = eot[s];
                                input.Consume();
                                // TODO: I had this as return accept[eot[s]]
                                // which assumed here that the EOT edge always
                                // went to an accept...faster to do this, but
                                // what about predicated edges coming from EOT
                                // target?
                                continue;
                            }

                            NoViableAlt( s, input );
                            return 0;
                        }

                        s = snext;
                        input.Consume();
                        continue;
                    }

                    if ( eot[s] >= 0 )
                    {
                        // EOT Transition?
                        DfaDebugMessage("EOT transition");
                        s = eot[s];
                        input.Consume();
                        continue;
                    }

                    if ( c == unchecked( (char)TokenTypes.EndOfFile ) && eof[s] >= 0 )
                    {
                        // EOF Transition to accept state?
                        DfaDebugMessage("accept via EOF; predict {0} from {1}", accept[eof[s]], eof[s]);
                        return accept[eof[s]];
                    }

                    // not in range and not EOF/EOT, must be invalid symbol
                    DfaDebugInvalidSymbol(s);

                    NoViableAlt( s, input );
                    return 0;
                }
            }
            finally
            {
                input.Rewind( mark );
            }
        }
Esempio n. 9
0
        /** Fill a list of all NFA states visited during the parse */
        protected virtual void ParseEngine( String startRule,
                                   NFAState start,
                                   NFAState stop,
                                   IIntStream input,
                                   Stack<object> ruleInvocationStack,
                                   IDebugEventListener actions,
                                   IList visitedStates )
        {
            NFAState s = start;
            if ( actions != null )
            {
                actions.EnterRule( s.nfa.grammar.FileName, start.enclosingRule.Name );
            }
            int t = input.LA( 1 );
            while ( s != stop )
            {
                if ( visitedStates != null )
                {
                    visitedStates.Add( s );
                }
                //Console.Out.WriteLine( "parse state " + s.stateNumber + " input=" + s.nfa.grammar.getTokenDisplayName( t ) );
                // CASE 1: decision state
                if ( s.DecisionNumber > 0 && s.nfa.grammar.GetNumberOfAltsForDecisionNFA( s ) > 1 )
                {
                    // decision point, must predict and jump to alt
                    DFA dfa = s.nfa.grammar.GetLookaheadDFA( s.DecisionNumber );
                    //if ( s.nfa.grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "decision: " +
                    //                   dfa.getNFADecisionStartState().Description +
                    //                   " input=" + s.nfa.grammar.getTokenDisplayName( t ) );
                    //}
                    int m = input.Mark();
                    int predictedAlt = Predict( dfa );
                    if ( predictedAlt == NFA.INVALID_ALT_NUMBER )
                    {
                        String description = dfa.NFADecisionStartState.Description;
                        NoViableAltException nvae =
                            new NoViableAltException( description,
                                                          dfa.DecisionNumber,
                                                          s.stateNumber,
                                                          input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( nvae );
                        }
                        input.Consume(); // recover
                        throw nvae;
                    }
                    input.Rewind( m );
                    int parseAlt =
                        s.TranslateDisplayAltToWalkAlt( predictedAlt );
                    //if ( s.nfa.grammar.type != GrammarType.Lexer )
                    //{
                    //    Console.Out.WriteLine( "predicted alt " + predictedAlt + ", parseAlt " + parseAlt );
                    //}
                    NFAState alt;
                    if ( parseAlt > s.nfa.grammar.GetNumberOfAltsForDecisionNFA( s ) )
                    {
                        // implied branch of loop etc...
                        alt = s.nfa.grammar.nfa.GetState( s.endOfBlockStateNumber );
                    }
                    else
                    {
                        alt = s.nfa.grammar.GetNFAStateForAltOfDecision( s, parseAlt );
                    }
                    s = (NFAState)alt.transition[0].target;
                    continue;
                }

                // CASE 2: finished matching a rule
                if ( s.IsAcceptState )
                { // end of rule node
                    if ( actions != null )
                    {
                        actions.ExitRule( s.nfa.grammar.FileName, s.enclosingRule.Name );
                    }
                    if ( ruleInvocationStack.Count == 0 )
                    {
                        // done parsing.  Hit the start state.
                        //Console.Out.WriteLine( "stack empty in stop state for " + s.enclosingRule );
                        break;
                    }
                    // pop invoking state off the stack to know where to return to
                    NFAState invokingState = (NFAState)ruleInvocationStack.Pop();
                    RuleClosureTransition invokingTransition =
                            (RuleClosureTransition)invokingState.transition[0];
                    // move to node after state that invoked this rule
                    s = invokingTransition.followState;
                    continue;
                }

                Transition trans = s.transition[0];
                Label label = trans.label;
                if ( label.IsSemanticPredicate )
                {
                    FailedPredicateException fpe =
                        new FailedPredicateException( input,
                                                     s.enclosingRule.Name,
                                                     "can't deal with predicates yet" );
                    if ( actions != null )
                    {
                        actions.RecognitionException( fpe );
                    }
                }

                // CASE 3: epsilon transition
                if ( label.IsEpsilon )
                {
                    // CASE 3a: rule invocation state
                    if ( trans is RuleClosureTransition )
                    {
                        ruleInvocationStack.Push( s );
                        s = (NFAState)trans.target;
                        //Console.Out.WriteLine( "call " + s.enclosingRule.name + " from " + s.nfa.grammar.getFileName() );
                        if ( actions != null )
                        {
                            actions.EnterRule( s.nfa.grammar.FileName, s.enclosingRule.Name );
                        }
                        // could be jumping to new grammar, make sure DFA created
                        if ( !s.nfa.grammar.AllDecisionDFAHaveBeenCreated )
                        {
                            s.nfa.grammar.CreateLookaheadDFAs();
                        }
                    }
                    // CASE 3b: plain old epsilon transition, just move
                    else
                    {
                        s = (NFAState)trans.target;
                    }
                }

                // CASE 4: match label on transition
                else if ( label.Matches( t ) )
                {
                    if ( actions != null )
                    {
                        if ( s.nfa.grammar.type == GrammarType.Parser ||
                             s.nfa.grammar.type == GrammarType.Combined )
                        {
                            actions.ConsumeToken( ( (ITokenStream)input ).LT( 1 ) );
                        }
                    }
                    s = (NFAState)s.transition[0].target;
                    input.Consume();
                    t = input.LA( 1 );
                }

                // CASE 5: error condition; label is inconsistent with input
                else
                {
                    if ( label.IsAtom )
                    {
                        MismatchedTokenException mte =
                            new MismatchedTokenException( label.Atom, input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( mte );
                        }
                        input.Consume(); // recover
                        throw mte;
                    }
                    else if ( label.IsSet )
                    {
                        MismatchedSetException mse =
                            new MismatchedSetException( ( (IntervalSet)label.Set ).ToRuntimeBitSet(),
                                                       input );
                        if ( actions != null )
                        {
                            actions.RecognitionException( mse );
                        }
                        input.Consume(); // recover
                        throw mse;
                    }
                    else if ( label.IsSemanticPredicate )
                    {
                        FailedPredicateException fpe =
                            new FailedPredicateException( input,
                                                         s.enclosingRule.Name,
                                                         label.SemanticContext.ToString() );
                        if ( actions != null )
                        {
                            actions.RecognitionException( fpe );
                        }
                        input.Consume(); // recover
                        throw fpe;
                    }
                    else
                    {
                        throw new RecognitionException( input ); // unknown error
                    }
                }
            }
            //Console.Out.WriteLine( "hit stop state for " + stop.enclosingRule );
            if ( actions != null )
            {
                actions.ExitRule( s.nfa.grammar.FileName, stop.enclosingRule.Name );
            }
        }
Esempio n. 10
0
        public virtual int Predict(IIntStream input)
        {
            if (this.debug)
            {
                Console.Error.WriteLine("Enter DFA.predict for decision " + (object)this.decisionNumber);
            }
            int marker = input.Mark();
            int s1     = 0;

            try
            {
                char ch;
                while (true)
                {
                    if (this.debug)
                    {
                        Console.Error.WriteLine("DFA " + (object)this.decisionNumber + " state " + (object)s1 + " LA(1)=" + (object)(char)input.LA(1) + "(" + (object)input.LA(1) + "), index=" + (object)input.Index);
                    }
                    int s2 = (int)this.special[s1];
                    if (s2 >= 0)
                    {
                        if (this.debug)
                        {
                            Console.Error.WriteLine("DFA " + (object)this.decisionNumber + " state " + (object)s1 + " is special state " + (object)s2);
                        }
                        s1 = this.SpecialStateTransition(this, s2, input);
                        if (this.debug)
                        {
                            Console.Error.WriteLine("DFA " + (object)this.decisionNumber + " returns from special state " + (object)s2 + " to " + (object)s1);
                        }
                        if (s1 != -1)
                        {
                            input.Consume();
                        }
                        else
                        {
                            break;
                        }
                    }
                    else if (this.accept[s1] < (short)1)
                    {
                        ch = (char)input.LA(1);
                        if ((int)ch >= (int)this.min[s1] && (int)ch <= (int)this.max[s1])
                        {
                            int num = (int)this.transition[s1][(int)ch - (int)this.min[s1]];
                            if (num < 0)
                            {
                                if (this.eot[s1] >= (short)0)
                                {
                                    if (this.debug)
                                    {
                                        Console.Error.WriteLine("EOT transition");
                                    }
                                    s1 = (int)this.eot[s1];
                                    input.Consume();
                                }
                                else
                                {
                                    goto label_23;
                                }
                            }
                            else
                            {
                                s1 = num;
                                input.Consume();
                            }
                        }
                        else if (this.eot[s1] >= (short)0)
                        {
                            if (this.debug)
                            {
                                Console.Error.WriteLine("EOT transition");
                            }
                            s1 = (int)this.eot[s1];
                            input.Consume();
                        }
                        else
                        {
                            goto label_29;
                        }
                    }
                    else
                    {
                        goto label_14;
                    }
                }
                this.NoViableAlt(s1, input);
                return(0);

label_14:
                if (this.debug)
                {
                    Console.Error.WriteLine("accept; predict " + (object)this.accept[s1] + " from state " + (object)s1);
                }
                return((int)this.accept[s1]);

label_23:
                this.NoViableAlt(s1, input);
                return(0);

label_29:
                if (ch == char.MaxValue && this.eof[s1] >= (short)0)
                {
                    if (this.debug)
                    {
                        Console.Error.WriteLine("accept via EOF; predict " + (object)this.accept[(int)this.eof[s1]] + " from " + (object)this.eof[s1]);
                    }
                    return((int)this.accept[(int)this.eof[s1]]);
                }
                if (this.debug)
                {
                    Console.Error.WriteLine("min[" + (object)s1 + "]=" + (object)this.min[s1]);
                    Console.Error.WriteLine("max[" + (object)s1 + "]=" + (object)this.max[s1]);
                    Console.Error.WriteLine("eot[" + (object)s1 + "]=" + (object)this.eot[s1]);
                    Console.Error.WriteLine("eof[" + (object)s1 + "]=" + (object)this.eof[s1]);
                    for (int index = 0; index < this.transition[s1].Length; ++index)
                    {
                        Console.Error.Write(((int)this.transition[s1][index]).ToString() + " ");
                    }
                    Console.Error.WriteLine();
                }
                this.NoViableAlt(s1, input);
                return(0);
            }
            finally
            {
                input.Rewind(marker);
            }
        }
		/// <summary>
		/// From the input stream, predict what alternative will succeed using this 
		/// DFA (representing the covering regular approximation to the underlying CFL).  
		/// </summary>
		/// <param name="input">Input stream</param>
		/// <returns>Return an alternative number 1..n.  Throw an exception upon error.</returns>
		public int Predict(IIntStream input)
		{
			int mark = input.Mark();	// remember where decision started in input
			int s = 0; // we always start at s0
			try
			{
				while (true)
				{
					int specialState = special[s];
					if (specialState >= 0)
					{
						s = specialStateTransitionHandler(this, specialState, input);
						if (s == -1)
						{
							NoViableAlt(s, input);
							return 0;
						}
						input.Consume();
						continue;
					}
					if (accept[s] >= 1)
					{
						return accept[s];
					}
					// look for a normal char transition
					char c = (char)input.LA(1);		// -1 == \uFFFF, all tokens fit in 65000 space
					if ((c >= min[s]) && (c <= max[s]))
					{
						int snext = transition[s][c - min[s]]; // move to next state
						if (snext < 0)
						{
							// was in range but not a normal transition
							// must check EOT, which is like the else clause.
							// eot[s]>=0 indicates that an EOT edge goes to another
							// state.
							if (eot[s] >= 0)  // EOT Transition to accept state?
							{
								s = eot[s];
								input.Consume();
								// TODO: I had this as return accept[eot[s]]
								// which assumed here that the EOT edge always
								// went to an accept...faster to do this, but
								// what about predicated edges coming from EOT
								// target?
								continue;
							}
							NoViableAlt(s, input);
							return 0;
						}
						s = snext;
						input.Consume();
						continue;
					}
					if (eot[s] >= 0)
					{  // EOT Transition?
						s = eot[s];
						input.Consume();
						continue;
					}
					if ((c == (char)Token.EOF) && (eof[s] >= 0))
					{  // EOF Transition to accept state?
						return accept[eof[s]];
					}
					// not in range and not EOF/EOT, must be invalid symbol
					NoViableAlt(s, input);
					return 0;
				}
			}
			finally
			{
				input.Rewind(mark);
			}
		}
        /// <summary>
        /// From the input stream, predict what alternative will succeed using this
        /// DFA (representing the covering regular approximation to the underlying CFL).
        /// </summary>
        /// <param name="input">Input stream</param>
        /// <returns>Return an alternative number 1..n.  Throw an exception upon error.</returns>
        public int Predict(IIntStream input)
        {
            int mark = input.Mark(); // remember where decision started in input
            int s    = 0;            // we always start at s0

            try
            {
                while (true)
                {
                    int specialState = special[s];
                    if (specialState >= 0)
                    {
                        s = specialStateTransitionHandler(this, specialState, input);
                        if (s == -1)
                        {
                            NoViableAlt(s, input);
                            return(0);
                        }
                        input.Consume();
                        continue;
                    }
                    if (accept[s] >= 1)
                    {
                        return(accept[s]);
                    }
                    // look for a normal char transition
                    char c = (char)input.LA(1);                                 // -1 == \uFFFF, all tokens fit in 65000 space
                    if ((c >= min[s]) && (c <= max[s]))
                    {
                        int snext = transition[s][c - min[s]];                         // move to next state
                        if (snext < 0)
                        {
                            // was in range but not a normal transition
                            // must check EOT, which is like the else clause.
                            // eot[s]>=0 indicates that an EOT edge goes to another
                            // state.
                            if (eot[s] >= 0)                              // EOT Transition to accept state?
                            {
                                s = eot[s];
                                input.Consume();
                                // TODO: I had this as return accept[eot[s]]
                                // which assumed here that the EOT edge always
                                // went to an accept...faster to do this, but
                                // what about predicated edges coming from EOT
                                // target?
                                continue;
                            }
                            NoViableAlt(s, input);
                            return(0);
                        }
                        s = snext;
                        input.Consume();
                        continue;
                    }
                    if (eot[s] >= 0)
                    {                      // EOT Transition?
                        s = eot[s];
                        input.Consume();
                        continue;
                    }
                    if ((c == (char)Token.EOF) && (eof[s] >= 0))
                    {                      // EOF Transition to accept state?
                        return(accept[eof[s]]);
                    }
                    // not in range and not EOF/EOT, must be invalid symbol
                    NoViableAlt(s, input);
                    return(0);
                }
            }
            finally
            {
                input.Rewind(mark);
            }
        }