public GetOptimizedTransition ( int i ) : Antlr4.Runtime.Atn.Transition | ||
i | int | |
return | Antlr4.Runtime.Atn.Transition |
/// <summary> /// Since the alternatives within any lexer decision are ordered by /// preference, this method stops pursuing the closure as soon as an accept /// state is reached. /// </summary> /// <remarks> /// Since the alternatives within any lexer decision are ordered by /// preference, this method stops pursuing the closure as soon as an accept /// state is reached. After the first accept state is reached by depth-first /// search from /// <code>config</code> /// , all other (potentially reachable) states for /// this rule would have a lower priority. /// </remarks> /// <returns> /// /// <code>true</code> /// if an accept state is reached, otherwise /// <code>false</code> /// . /// </returns> protected internal virtual bool Closure(ICharStream input, ATNConfig config, ATNConfigSet configs, bool speculative) { if (config.State is RuleStopState) { PredictionContext context = config.Context; if (context.IsEmpty) { configs.AddItem(config); return(true); } else { if (context.HasEmpty) { configs.AddItem(config.Transform(config.State, PredictionContext.EmptyFull)); return(true); } } for (int i = 0; i < context.Size; i++) { int returnStateNumber = context.GetReturnState(i); if (returnStateNumber == PredictionContext.EmptyFullStateKey) { continue; } PredictionContext newContext = context.GetParent(i); // "pop" return state ATNState returnState = atn.states[returnStateNumber]; ATNConfig c = ATNConfig.Create(returnState, config.Alt, newContext); if (Closure(input, c, configs, speculative)) { return(true); } } return(false); } // optimization if (!config.State.OnlyHasEpsilonTransitions) { configs.AddItem(config); } ATNState p = config.State; for (int i_1 = 0; i_1 < p.NumberOfOptimizedTransitions; i_1++) { Transition t = p.GetOptimizedTransition(i_1); ATNConfig c = GetEpsilonTarget(input, config, t, configs, speculative); if (c != null) { if (Closure(input, c, configs, speculative)) { return(true); } } } return(false); }
/// <summary> /// Since the alternatives within any lexer decision are ordered by /// preference, this method stops pursuing the closure as soon as an accept /// state is reached. /// </summary> /// <remarks> /// Since the alternatives within any lexer decision are ordered by /// preference, this method stops pursuing the closure as soon as an accept /// state is reached. After the first accept state is reached by depth-first /// search from /// <paramref name="config"/> /// , all other (potentially reachable) states for /// this rule would have a lower priority. /// </remarks> /// <returns> /// /// <see langword="true"/> /// if an accept state is reached, otherwise /// <see langword="false"/> /// . /// </returns> protected internal virtual bool Closure(ICharStream input, ATNConfig config, ATNConfigSet configs, bool currentAltReachedAcceptState, bool speculative, bool treatEofAsEpsilon) { if (config.State is RuleStopState) { PredictionContext context = config.Context; if (context.IsEmpty) { configs.Add(config); return(true); } else { if (context.HasEmpty) { configs.Add(config.Transform(config.State, PredictionContext.EmptyFull, true)); currentAltReachedAcceptState = true; } } for (int i = 0; i < context.Size; i++) { int returnStateNumber = context.GetReturnState(i); if (returnStateNumber == PredictionContext.EmptyFullStateKey) { continue; } PredictionContext newContext = context.GetParent(i); // "pop" return state ATNState returnState = atn.states[returnStateNumber]; ATNConfig c = config.Transform(returnState, newContext, false); currentAltReachedAcceptState = Closure(input, c, configs, currentAltReachedAcceptState, speculative, treatEofAsEpsilon); } return(currentAltReachedAcceptState); } // optimization if (!config.State.OnlyHasEpsilonTransitions) { if (!currentAltReachedAcceptState || !config.PassedThroughNonGreedyDecision) { configs.Add(config); } } ATNState p = config.State; for (int i_1 = 0; i_1 < p.NumberOfOptimizedTransitions; i_1++) { Transition t = p.GetOptimizedTransition(i_1); ATNConfig c = GetEpsilonTarget(input, config, t, configs, speculative, treatEofAsEpsilon); if (c != null) { currentAltReachedAcceptState = Closure(input, c, configs, currentAltReachedAcceptState, speculative, treatEofAsEpsilon); } } return(currentAltReachedAcceptState); }
private static int CombineChainedEpsilons(ATN atn) { int removedEdges = 0; foreach (ATNState state in atn.states) { if (!state.OnlyHasEpsilonTransitions || state is RuleStopState) { continue; } IList <Transition> optimizedTransitions = null; for (int i = 0; i < state.NumberOfOptimizedTransitions; i++) { Transition transition = state.GetOptimizedTransition(i); ATNState intermediate = transition.target; if (transition.TransitionType != TransitionType.EPSILON || ((EpsilonTransition)transition).OutermostPrecedenceReturn != -1 || intermediate.StateType != StateType.Basic || !intermediate.OnlyHasEpsilonTransitions) { if (optimizedTransitions != null) { optimizedTransitions.Add(transition); } goto nextTransition_continue; } for (int j = 0; j < intermediate.NumberOfOptimizedTransitions; j++) { if (intermediate.GetOptimizedTransition(j).TransitionType != TransitionType.EPSILON || ((EpsilonTransition)intermediate.GetOptimizedTransition(j)).OutermostPrecedenceReturn != -1) { if (optimizedTransitions != null) { optimizedTransitions.Add(transition); } goto nextTransition_continue; } } removedEdges++; if (optimizedTransitions == null) { optimizedTransitions = new List <Transition>(); for (int j_1 = 0; j_1 < i; j_1++) { optimizedTransitions.Add(state.GetOptimizedTransition(j_1)); } } for (int j_2 = 0; j_2 < intermediate.NumberOfOptimizedTransitions; j_2++) { ATNState target = intermediate.GetOptimizedTransition(j_2).target; optimizedTransitions.Add(new EpsilonTransition(target)); } nextTransition_continue :; } if (optimizedTransitions != null) { if (state.IsOptimized) { while (state.NumberOfOptimizedTransitions > 0) { state.RemoveOptimizedTransition(state.NumberOfOptimizedTransitions - 1); } } foreach (Transition transition in optimizedTransitions) { state.AddOptimizedTransition(transition); } } } return(removedEdges); }
private static int InlineSetRules(ATN atn) { int inlinedCalls = 0; Transition[] ruleToInlineTransition = new Transition[atn.ruleToStartState.Length]; for (int i = 0; i < atn.ruleToStartState.Length; i++) { RuleStartState startState = atn.ruleToStartState[i]; ATNState middleState = startState; while (middleState.OnlyHasEpsilonTransitions && middleState.NumberOfOptimizedTransitions == 1 && middleState.GetOptimizedTransition(0).TransitionType == TransitionType.EPSILON) { middleState = middleState.GetOptimizedTransition(0).target; } if (middleState.NumberOfOptimizedTransitions != 1) { continue; } Transition matchTransition = middleState.GetOptimizedTransition(0); ATNState matchTarget = matchTransition.target; if (matchTransition.IsEpsilon || !matchTarget.OnlyHasEpsilonTransitions || matchTarget.NumberOfOptimizedTransitions != 1 || !(matchTarget.GetOptimizedTransition(0).target is RuleStopState)) { continue; } switch (matchTransition.TransitionType) { case TransitionType.ATOM: case TransitionType.RANGE: case TransitionType.SET: { ruleToInlineTransition[i] = matchTransition; break; } case TransitionType.NOT_SET: case TransitionType.WILDCARD: { // not implemented yet continue; } default: { continue; } } } for (int stateNumber = 0; stateNumber < atn.states.Count; stateNumber++) { ATNState state = atn.states[stateNumber]; if (state.ruleIndex < 0) { continue; } IList <Transition> optimizedTransitions = null; for (int i_1 = 0; i_1 < state.NumberOfOptimizedTransitions; i_1++) { Transition transition = state.GetOptimizedTransition(i_1); if (!(transition is RuleTransition)) { if (optimizedTransitions != null) { optimizedTransitions.Add(transition); } continue; } RuleTransition ruleTransition = (RuleTransition)transition; Transition effective = ruleToInlineTransition[ruleTransition.target.ruleIndex]; if (effective == null) { if (optimizedTransitions != null) { optimizedTransitions.Add(transition); } continue; } if (optimizedTransitions == null) { optimizedTransitions = new List <Transition>(); for (int j = 0; j < i_1; j++) { optimizedTransitions.Add(state.GetOptimizedTransition(i_1)); } } inlinedCalls++; ATNState target = ruleTransition.followState; ATNState intermediateState = new BasicState(); intermediateState.SetRuleIndex(target.ruleIndex); atn.AddState(intermediateState); optimizedTransitions.Add(new EpsilonTransition(intermediateState)); switch (effective.TransitionType) { case TransitionType.ATOM: { intermediateState.AddTransition(new AtomTransition(target, ((AtomTransition)effective).token)); break; } case TransitionType.RANGE: { intermediateState.AddTransition(new RangeTransition(target, ((RangeTransition)effective).from, ((RangeTransition)effective).to)); break; } case TransitionType.SET: { intermediateState.AddTransition(new SetTransition(target, effective.Label)); break; } default: { throw new NotSupportedException(); } } } if (optimizedTransitions != null) { if (state.IsOptimized) { while (state.NumberOfOptimizedTransitions > 0) { state.RemoveOptimizedTransition(state.NumberOfOptimizedTransitions - 1); } } foreach (Transition transition in optimizedTransitions) { state.AddOptimizedTransition(transition); } } } return(inlinedCalls); }