proposal/RFC: add bSwap to base in Data.Bits

Herbert Valerio Riedel hvr at
Thu May 16 12:40:23 CEST 2013

On 2013-05-16 08:59:28 +0200, Vincent Hanquez wrote:
> I'ld want to propose to extends Bits to do so generically:
>   class Bits a where
>     ...  
>     bSwap : a -> a
> I'm attaching a patch that do as explained, and add a default implementation
> for bSwap, so that compatibility is assured for existing instances.

I'm not against providing "generic" byteswap primitives, but I'm
skeptical about adding a *byte*-swap to the 'Bits' typeclass, whose
declared scope is according to the documentation:

| The Bits class defines bitwise operations over integral types.

And I haven't seen any operation relying on the concept of bytes in

Wouldn't it be more logical to add a new typeclass depending on the
byte-notion such as e.g.

  class Bits a => Bytes a where

which could then provide byte-operations such as little/big endian


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