Bug 132515 Expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error
Description: Add an expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error.The nesting "Toltal" seem not to be work. Step to reproduce: 1.new a datasource and dataset 2.drag the dataset to layout veiw for a table 3.set a group on the table 4.Insert a data into the group header with the expression e.g. "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" Actual result: An error was thrown out Expected result: It should work correctly in order to support some requirments
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/ExpressionProcessor.java
context ) );
					if ( op1 != null )
						op1.setHandle( helper.compileExpression( op1.getText( ),
								context ) );
					if ( op2 != null )
						op2.setHandle( helper.compileExpression( op2.getText( ),
								context ) );
				}
				else if ( baseExpression instanceof IScriptExpression )
				{
					IScriptExpression scriptExpr = (IScriptExpression) baseExpression;
					scriptExpr.setHandle( helper.compileExpression( scriptExpr.getText( ),
							context ) );
				}
			}
		}
		finally
		{
			Context.exit( );
		}
		
		calculate( );
		helper.setExpressionType( exprType, level );
	}
	
	/**
	 * Set the expression state. if the expression can be evaluated, its state
	 * should be set true
	 */
	private void setExpressionState( )