NCalcParser.shiftExpression C# (CSharp) Method

    public NCalcParser.shiftExpression_return shiftExpression()
    {
        NCalcParser.shiftExpression_return retval = new NCalcParser.shiftExpression_return();
        retval.Start = input.LT(1);

        CommonTree root_0 = null;

        IToken string_literal16 = null;
        IToken string_literal17 = null;
        NCalcParser.additiveExpression_return left = null;

        NCalcParser.additiveExpression_return right = null;

        CommonTree string_literal16_tree=null;
        CommonTree string_literal17_tree=null;

        BinaryExpressionType type = BinaryExpressionType.Unknown;

        try
        {
            // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:163:2: (left= additiveExpression ( ( '<<' | '>>' ) right= additiveExpression )* )
            // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:163:4: left= additiveExpression ( ( '<<' | '>>' ) right= additiveExpression )*
            {
                root_0 = (CommonTree)adaptor.GetNilNode();

                PushFollow(FOLLOW_additiveExpression_in_shiftExpression560);
                left = additiveExpression();
                state.followingStackPointer--;

                adaptor.AddChild(root_0, left.Tree);
                 retval.value =  ((left != null) ? left.value : null);
                // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:163:54: ( ( '<<' | '>>' ) right= additiveExpression )*
                do
                {
                    int alt12 = 2;
                    int LA12_0 = input.LA(1);

                    if ( ((LA12_0 >= 36 && LA12_0 <= 37)) )
                    {
                        alt12 = 1;
                    }

                    switch (alt12)
                    {
                        case 1 :
                            // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:164:4: ( '<<' | '>>' ) right= additiveExpression
                            {
                                // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:164:4: ( '<<' | '>>' )
                                int alt11 = 2;
                                int LA11_0 = input.LA(1);

                                if ( (LA11_0 == 36) )
                                {
                                    alt11 = 1;
                                }
                                else if ( (LA11_0 == 37) )
                                {
                                    alt11 = 2;
                                }
                                else
                                {
                                    NoViableAltException nvae_d11s0 =
                                        new NoViableAltException("", 11, 0, input);

                                    throw nvae_d11s0;
                                }
                                switch (alt11)
                                {
                                    case 1 :
                                        // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:164:6: '<<'
                                        {
                                            string_literal16=(IToken)Match(input,36,FOLLOW_36_in_shiftExpression571);
                                                string_literal16_tree = (CommonTree)adaptor.Create(string_literal16);
                                                adaptor.AddChild(root_0, string_literal16_tree);

                                             type = BinaryExpressionType.LeftShift;

                                        }
                                        break;
                                    case 2 :
                                        // C:\\Users\\s.ros\\Documents\\Développement\\NCalc\\Grammar\\NCalc.g:165:6: '>>'
                                        {
                                            string_literal17=(IToken)Match(input,37,FOLLOW_37_in_shiftExpression581);
                                                string_literal17_tree = (CommonTree)adaptor.Create(string_literal17);
                                                adaptor.AddChild(root_0, string_literal17_tree);

                                             type = BinaryExpressionType.RightShift;

                                        }
                                        break;

                                }

                                PushFollow(FOLLOW_additiveExpression_in_shiftExpression593);
                                right = additiveExpression();
                                state.followingStackPointer--;

                                adaptor.AddChild(root_0, right.Tree);
                                 retval.value =  new BinaryExpression(type, retval.value, ((right != null) ? right.value : null));

                            }
                            break;

                        default:
                            goto loop12;
                    }
                } while (true);

                loop12:
                    ;	// Stops C# compiler whining that label 'loop12' has no statements

            }

            retval.Stop = input.LT(-1);

                retval.Tree = (CommonTree)adaptor.RulePostProcessing(root_0);
                adaptor.SetTokenBoundaries(retval.Tree, (IToken) retval.Start, (IToken) retval.Stop);
        }
        catch (RecognitionException re)
        {
            ReportError(re);
            Recover(input,re);
        // Conversion of the second argument necessary, but harmless
        retval.Tree = (CommonTree)adaptor.ErrorNode(input, (IToken) retval.Start, input.LT(-1), re);

        }
        finally
        {
        }
        return retval;
    }