Antlr4.Tool.GrammarParserInterpreter.VisitDecisionState C# (CSharp) Method

        protected override int VisitDecisionState(DecisionState p)
        {
            int predictedAlt = base.VisitDecisionState(p);
            if (p.NumberOfTransitions > 1)
            {
                //			System.out.println("decision "+p.decision+": "+predictedAlt);
                if (p.decision == this.overrideDecision &&
                    this._input.Index == this.overrideDecisionInputIndex)
                {
                    overrideDecisionRoot = (GrammarInterpreterRuleContext)Context;
                }
            }

            GrammarInterpreterRuleContext ctx = (GrammarInterpreterRuleContext)_ctx;
            if (decisionStatesThatSetOuterAltNumInContext.Get(p.stateNumber))
            {
                ctx.OuterAlternative = predictedAlt;
                Rule r = g.GetRule(p.ruleIndex);
                if (atn.ruleToStartState[r.index].isPrecedenceRule)
                {
                    int[] alts = stateToAltsMap[p.stateNumber];
                    LeftRecursiveRule lr = (LeftRecursiveRule)g.GetRule(p.ruleIndex);
                    if (p.StateType == StateType.BlockStart)
                    {
                        if (alts == null)
                        {
                            alts = lr.GetPrimaryAlts();
                            stateToAltsMap[p.stateNumber] = alts; // cache it
                        }
                    }
                    else if (p.StateType == StateType.StarBlockStart)
                    {
                        if (alts == null)
                        {
                            alts = lr.GetRecursiveOpAlts();
                            stateToAltsMap[p.stateNumber] = alts; // cache it
                        }
                    }
                    ctx.OuterAlternative = alts[predictedAlt];
                }
            }

            return predictedAlt;
        }