Boo.Lang.Compiler.Steps.GeneratorMethodProcessor.CreateMoveNext C# (CSharp) Метод

        void CreateMoveNext()
        {
            Method generator = _generator.Method;

            BooMethodBuilder methodBuilder = _enumerator.AddVirtualMethod("MoveNext", TypeSystemServices.BoolType);
            methodBuilder.Method.LexicalInfo = generator.LexicalInfo;
            _moveNext = methodBuilder.Entity;

            foreach (Local local in generator.Locals)
            {
                InternalLocal entity = (InternalLocal)local.Entity;

                Field field = _enumerator.AddInternalField("$" + entity.Name + "$" + _context.AllocIndex(), entity.Type);
                _mapping[entity] = field.Entity;
            }
            generator.Locals.Clear();

            foreach (ParameterDeclaration parameter in generator.Parameters)
            {
                InternalParameter entity = (InternalParameter)parameter.Entity;
                if (entity.IsUsed)
                {
                    Field field = DeclareFieldInitializedFromConstructorParameter(_enumerator, _enumeratorConstructor,
                                                                                  entity.Name,
                                                                                  entity.Type);
                    _mapping[entity] = field.Entity;
                }
            }

            methodBuilder.Body.Add(CreateLabel(generator));
            // Visit() needs to know the number of the finished state
            _finishedStateNumber = _labels.Count;
            LabelStatement finishedLabel = CreateLabel(generator);
            methodBuilder.Body.Add(generator.Body);
            generator.Body.Clear();

            Visit(methodBuilder.Body);

            methodBuilder.Body.Add(CreateYieldInvocation(null, _finishedStateNumber));
            methodBuilder.Body.Add(finishedLabel);

            methodBuilder.Body.Insert(0,
                           CodeBuilder.CreateSwitch(
                           	this.LexicalInfo,
                           	CodeBuilder.CreateMemberReference(_state),
                           	_labels));

            // if the method contains converted try statements, put it in a try/failure block
            if (_convertedTryStatements.Count > 0)
            {
                IMethod dispose = CreateDisposeMethod();

                TryStatement tryFailure = new TryStatement();
                tryFailure.ProtectedBlock.Add(methodBuilder.Body);
                tryFailure.FailureBlock = new Block();
                tryFailure.FailureBlock.Add(CallMethodOnSelf(dispose));
                methodBuilder.Body.Clear();
                methodBuilder.Body.Add(tryFailure);
            }
        }