On Tue, Jan 30, 2007 at 09:38:26AM +0000, Ross Paterson wrote:
> On Tue, Jan 30, 2007 at 09:52:01AM +1100, Donald Bruce Stewart wrote:
> > ross:
> > > why do you need a Put monad, which always seems to have
> > > the argument type ()? Monoids really are underappreciated.
> >
> > For the syntax, and So that people can directly port their code from
> > NewBinary. (The instances are basically unchanged).
>
> And so the successor to binary must have the same interface, and so on
> forever. The backward compatibility argument seems weak to me, leaving
> only the advantage of do-notation.
How about having both interfaces, so you can use the one you like
better?
class Binary t where
-- | Encode a value in the Put monad.
put :: t -> Put
put x = Put ((), build x)
-- | Encode a value using the Builder monoid
build :: t -> Builder
build x = snd (unPut (put x))
-- | Decode a value in the Get monad
get :: Get t
The downside is that GHC probably wouldn't warn about undefined methods,
or would it?
Best regards
Tomasz
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
