[htoolkit-users] Do you really like to reeimplement getRow again and again?

[Marc W. <mar...@gm...>]

What aboou tadding something like the following to the distribution ?

=============  =======================================================
module GetRows where
import Control.Monad
import Database.HSQL

fieldNames  :: Statement -> [ String ]
fieldNames  = (map (\(a,_,_) -> a)) . getFieldsTypes 

getRow2 :: (SqlBind a, SqlBind b) => (a -> b -> r) -> Statement -> IO r
getRow2 f stmt =
  let fNs =  fieldNames stmt
  in  liftM2 f (getFieldValue stmt (fNs !! 0))
           (getFieldValue stmt (fNs !! 1))
           
getRow3 :: (SqlBind a, SqlBind b, SqlBind c) => (a -> b -> c -> r) -> Statement -> IO r
getRow3 f stmt =
  let fNs =  fieldNames stmt
  in  liftM3 f (getFieldValue stmt (fNs !! 0))
           (getFieldValue stmt (fNs !! 1))
           (getFieldValue stmt (fNs !! 2))

getRow4 :: (SqlBind a, SqlBind b, SqlBind c, SqlBind d) => (a -> b -> c -> d -> r) -> Statement -> IO r
getRow4 f stmt =
  let fNs =  fieldNames stmt
  in  liftM4 f (getFieldValue stmt (fNs !! 0))
           (getFieldValue stmt (fNs !! 1))
           (getFieldValue stmt (fNs !! 2))
           (getFieldValue stmt (fNs !! 3))
[...]
=============  =======================================================

That's not a perfect implementation but it allows you to write just:
rows = collectRows (getRow3 (,,)) stmt

Sincerly
Marc Weber