Antlr4.Runtime.Atn.ATNDeserializer.CombineChainedEpsilons C# (CSharp) Метод

        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;
        }