"Simon Marlow" writes:

...

shiftL 2 . clearBit 7 . setBit 4 . setBit 1

instead of flip shiftL 2 . flip clearBit 7 . flip setBit 4 . flip setBit 1

or (`shiftL` 2) . (`clearBit` 7) . (`setBit` 4) . (`setBit` 1)

On the whole I agree, but I'm inclined against changing this because it would break so much code gratuitously. I vote for just putting this down to a small mistake in the original design, and leaving it. If there's overwhelming support for the change of course we'll make it, but I doubt there will be.

For what it's worth, the old library NHC.Bits http://cvs.haskell.org/cgi-bin/cvsweb.cgi/nhc98/src/prelude/Bit/Bit.hs implements the 'set' and 'clear' operations with arguments the natural way round, although the left and right shift have the same order as Data.Bits and the C language. I slightly prefer the NHC names ^>> and ^<< for shifting too, since they are naturally infix. Henning's example composition would look like this: (^<< 2) . clear 7 . set 4 . set 1 I suppose if you didn't like the names and argument ordering in Data.Bits, it would be easy enough to layer your own preferred API on top, e.g. module My.Bits where import qualified Data.Bits class Data.Bits a => Bits a where shiftL :: Int -> a -> a shiftR :: Int -> a -> a shiftL = flip Data.Bits.shiftL shiftR = flip Data.Bits.shiftR ... etc Regards, Malcolm