On Sat, Mar 21, 2009 at 04:19:05PM -0000, Sittampalam, Ganesh wrote:
Ross Paterson wrote:
The combination transformers + monads-fd is close to a compatible replacement for mtl at the source level, except that State, Writer, etc are now type synonyms, which will break some code. Of course the package names are also different. We can't just rename monads-fd as mtl-2.0, because Control.Monad.Identity and Control.Monad.Trans are in the transformers package. But we could make a compatibility version of mtl along the lines of base3-compat. (And we need to rename the modules in monads-tf.)
The compatibility layer could continue to export the old separate types for State, Writer, etc, couldn't it?
It could, though then they'd be different types than the transformer versions. There's a trade-off.
Are there any problems with adding transformers and monads-fd to extralibs pending the Haskell Platform being ready?
That should work, but that wouldn't be till September/October. I'm not sure what the HP schedule is. Another possibility is to upload mtl-2.0 as a compatibility layer.