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/executor/transform/IComputedColumnsState.java
{
	/**
	 * Whether the value of expression with given index is available or not.
	 * 
	 * @param index
	 *            the index of expression.
	 * @return
	 */
	public boolean isValueAvailable( int index );
	/**
	 * TODO Remove it The name of ComputedColumn with given index.
	 * 
	 * @param index
	 * @return
	 */
	public String getName( int index );
	/**
	 * TODO Remove it The expression of ComputedColumn with given index.
	 * 
	 * @param index
	 * @return