ES3Parser.postfixExpression C# (CSharp) Method

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

        object root_0 = null;

        ES3Parser.leftHandSideExpression_return left = default(ES3Parser.leftHandSideExpression_return);

        ES3Parser.postfixOperator_return post = default(ES3Parser.postfixOperator_return);



        try 
    	{
            // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1092:2: (left= leftHandSideExpression (post= postfixOperator )? )
            // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1092:4: left= leftHandSideExpression (post= postfixOperator )?
            {
            	root_0 = (object)adaptor.GetNilNode();

            	PushFollow(FOLLOW_leftHandSideExpression_in_postfixExpression3782);
            	left = leftHandSideExpression();
            	state.followingStackPointer--;

            	adaptor.AddChild(root_0, left.Tree);
            	 retval.value =  left.value; if (input.LA(1) == INC || input.LA(1) == DEC) PromoteEOL(null);  
            	// C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1092:122: (post= postfixOperator )?
            	int alt22 = 2;
            	int LA22_0 = input.LA(1);

            	if ( ((LA22_0 >= INC && LA22_0 <= DEC)) )
            	{
            	    alt22 = 1;
            	}
            	switch (alt22) 
            	{
            	    case 1 :
            	        // C:\\Users\\s.ros\\Projets\\Jint\\Jint\\ES3.g:1092:124: post= postfixOperator
            	        {
            	        	PushFollow(FOLLOW_postfixOperator_in_postfixExpression3790);
            	        	post = postfixOperator();
            	        	state.followingStackPointer--;

            	        	root_0 = (object)adaptor.BecomeRoot(post.Tree, root_0);
            	        	 retval.value =  new UnaryExpression(post.value, retval.value); 

            	        }
            	        break;

            	}


            }

            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 "postfixExpression"