ES3Parser.shiftExpression C# (CSharp) Method

    public ES3Parser.shiftExpression_return shiftExpression() // throws RecognitionException [1]
    {   
        ES3Parser.shiftExpression_return retval = new ES3Parser.shiftExpression_return();
        retval.Start = input.LT(1);

        object root_0 = null;

        IToken SHL43 = null;
        IToken SHR44 = null;
        IToken SHU45 = null;
        ES3Parser.additiveExpression_return left = default(ES3Parser.additiveExpression_return);

        ES3Parser.additiveExpression_return right = default(ES3Parser.additiveExpression_return);


        object SHL43_tree=null;
        object SHR44_tree=null;
        object SHU45_tree=null;


        	BinaryExpressionType type = BinaryExpressionType.Unknown;

        try 
    	{
            // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1158:2: (left= additiveExpression ( ( SHL | SHR | SHU ) right= additiveExpression )* )
            // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1158:4: left= additiveExpression ( ( SHL | SHR | SHU ) right= additiveExpression )*
            {
            	root_0 = (object)adaptor.GetNilNode();

            	PushFollow(FOLLOW_additiveExpression_in_shiftExpression4095);
            	left = additiveExpression();
            	state.followingStackPointer--;

            	adaptor.AddChild(root_0, left.Tree);
            	 retval.value =  left.value; 
            	// C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1158:53: ( ( SHL | SHR | SHU ) right= additiveExpression )*
            	do 
            	{
            	    int alt31 = 2;
            	    int LA31_0 = input.LA(1);

            	    if ( ((LA31_0 >= SHL && LA31_0 <= SHU)) )
            	    {
            	        alt31 = 1;
            	    }


            	    switch (alt31) 
            		{
            			case 1 :
            			    // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1159:3: ( SHL | SHR | SHU ) right= additiveExpression
            			    {
            			    	// C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1159:3: ( SHL | SHR | SHU )
            			    	int alt30 = 3;
            			    	switch ( input.LA(1) ) 
            			    	{
            			    	case SHL:
            			    		{
            			    	    alt30 = 1;
            			    	    }
            			    	    break;
            			    	case SHR:
            			    		{
            			    	    alt30 = 2;
            			    	    }
            			    	    break;
            			    	case SHU:
            			    		{
            			    	    alt30 = 3;
            			    	    }
            			    	    break;
            			    		default:
            			    		    NoViableAltException nvae_d30s0 =
            			    		        new NoViableAltException("", 30, 0, input);

            			    		    throw nvae_d30s0;
            			    	}

            			    	switch (alt30) 
            			    	{
            			    	    case 1 :
            			    	        // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1159:5: SHL
            			    	        {
            			    	        	SHL43=(IToken)Match(input,SHL,FOLLOW_SHL_in_shiftExpression4106); 
            			    	        		SHL43_tree = (object)adaptor.Create(SHL43);
            			    	        		adaptor.AddChild(root_0, SHL43_tree);

            			    	        	 type= BinaryExpressionType.LeftShift; 

            			    	        }
            			    	        break;
            			    	    case 2 :
            			    	        // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1160:5: SHR
            			    	        {
            			    	        	SHR44=(IToken)Match(input,SHR,FOLLOW_SHR_in_shiftExpression4114); 
            			    	        		SHR44_tree = (object)adaptor.Create(SHR44);
            			    	        		adaptor.AddChild(root_0, SHR44_tree);

            			    	        	 type= BinaryExpressionType.RightShift; 

            			    	        }
            			    	        break;
            			    	    case 3 :
            			    	        // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1161:5: SHU
            			    	        {
            			    	        	SHU45=(IToken)Match(input,SHU,FOLLOW_SHU_in_shiftExpression4122); 
            			    	        		SHU45_tree = (object)adaptor.Create(SHU45);
            			    	        		adaptor.AddChild(root_0, SHU45_tree);

            			    	        	 type= BinaryExpressionType.UnsignedRightShift; 

            			    	        }
            			    	        break;

            			    	}

            			    	PushFollow(FOLLOW_additiveExpression_in_shiftExpression4133);
            			    	right = additiveExpression();
            			    	state.followingStackPointer--;

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

            			    }
            			    break;

            			default:
            			    goto loop31;
            	    }
            	} while (true);

            	loop31:
            		;	// Stops C# compiler whining that label 'loop31' has no statements


            }

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

            	retval.Tree = (object)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 = (object)adaptor.ErrorNode(input, (IToken) retval.Start, input.LT(-1), re);

        }
        finally 
    	{
        }
        return retval;
    }
    // $ANTLR end "shiftExpression"