-- | The following are all common aggregate operations

-- | The Sum aggregate operation
raggSum :: 
        ColumnName -- ^ source column
    ->  ColumnName -- ^ target column
    ->  RAggOperation
raggSum src trg = RAggOperation {
                 sourceCol = src
                ,targetCol = trg                                 
                ,aggFunc = \rtab -> createRtuple [(trg, sumFold src trg rtab)]  
        }
raggSum :: 
        ColumnName -- ^ source column
    ->  ColumnName -- ^ target column
    ->  RAggOperation
raggSum src trg = RAggOperation {
                 sourceCol = src
                ,targetCol = trg                                 
                ,aggFunc = \rtab -> createRtuple [(trg, sumFold src trg rtab)]  
        }
raggSum src trg = RAggOperation {
                 sourceCol = src
                ,targetCol = trg                                 
                ,aggFunc = \rtab -> createRtuple [(trg, sumFold src trg rtab)]  
        }