private static int OptimizeSets(ATN atn, bool preserveOrder) { if (preserveOrder) { // this optimization currently doesn't preserve edge order. return 0; } int removedPaths = 0; IList<DecisionState> decisions = atn.decisionToState; foreach (DecisionState decision in decisions) { IntervalSet setTransitions = new IntervalSet(); for (int i = 0; i < decision.NumberOfOptimizedTransitions; i++) { Transition epsTransition = decision.GetOptimizedTransition(i); if (!(epsTransition is EpsilonTransition)) { continue; } if (epsTransition.target.NumberOfOptimizedTransitions != 1) { continue; } Transition transition = epsTransition.target.GetOptimizedTransition(0); if (!(transition.target is BlockEndState)) { continue; } if (transition is NotSetTransition) { // TODO: not yet implemented continue; } if (transition is AtomTransition || transition is RangeTransition || transition is SetTransition) { setTransitions.Add(i); } } if (setTransitions.Count <= 1) { continue; } IList<Transition> optimizedTransitions = new List<Transition>(); for (int i_1 = 0; i_1 < decision.NumberOfOptimizedTransitions; i_1++) { if (!setTransitions.Contains(i_1)) { optimizedTransitions.Add(decision.GetOptimizedTransition(i_1)); } } ATNState blockEndState = decision.GetOptimizedTransition(setTransitions.MinElement).target.GetOptimizedTransition(0).target; IntervalSet matchSet = new IntervalSet(); for (int i_2 = 0; i_2 < setTransitions.GetIntervals().Count; i_2++) { Interval interval = setTransitions.GetIntervals()[i_2]; for (int j = interval.a; j <= interval.b; j++) { Transition matchTransition = decision.GetOptimizedTransition(j).target.GetOptimizedTransition(0); if (matchTransition is NotSetTransition) { throw new NotSupportedException("Not yet implemented."); } else { matchSet.AddAll(matchTransition.Label); } } } Transition newTransition; if (matchSet.GetIntervals().Count == 1) { if (matchSet.Count == 1) { newTransition = new AtomTransition(blockEndState, matchSet.MinElement); } else { Interval matchInterval = matchSet.GetIntervals()[0]; newTransition = new RangeTransition(blockEndState, matchInterval.a, matchInterval.b); } } else { newTransition = new SetTransition(blockEndState, matchSet); } ATNState setOptimizedState = new BasicState(); setOptimizedState.SetRuleIndex(decision.ruleIndex); atn.AddState(setOptimizedState); setOptimizedState.AddTransition(newTransition); optimizedTransitions.Add(new EpsilonTransition(setOptimizedState)); removedPaths += decision.NumberOfOptimizedTransitions - optimizedTransitions.Count; if (decision.IsOptimized) { while (decision.NumberOfOptimizedTransitions > 0) { decision.RemoveOptimizedTransition(decision.NumberOfOptimizedTransitions - 1); } } foreach (Transition transition_1 in optimizedTransitions) { decision.AddOptimizedTransition(transition_1); } } return removedPaths; }