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/IExpressionProcessor.java
* 
	 * @param it
	 */
	public void setResultIterator( IResultIterator it );
	/**
	 * Set the result iterator against which the value of aggregations will be
	 * calculated.
	 * 
	 * @param it
	 */
	public void setResultSetMetaData( IResultClass rsMetaData );
	/**
	 * Set the query to be used by ExpressionProcessor
	 * 
	 * @param query
	 */
	public void setQuery( BaseQuery query );
	/**
	 * Clear the temp variables when the IExpressionProcessor is no longer used.
	 * 
	 */
	public void clear( );
	
	public void prepareComputedColumns( IComputedColumnsState iccState );
	
	public void setResultSetPopulator( ResultSetPopulator rsPopulator );
	
	public void setDataSetMode( boolean isDataSetMode );
}