mtl, transformers, and monads-fd are in an unhappy place

Ross Paterson ross at
Fri Sep 10 19:47:09 EDT 2010

On Fri, Sep 10, 2010 at 12:32:38PM -0700, Bryan O'Sullivan wrote:
> Greg Collins mentioned that there's some kind of plan for mtl to become
> a shell package that depends on transformers and monads-fd.  Given my
> experience, I'd consider advancing this plan and getting it into the
> next Haskell Platform release (and ready before GHC 7 ships) to be a
> matter of the utmost urgency.

The plan is to rename the current monads-fd (which depends on transformers)
as version 2.0 of mtl.  Now does seem to be the time to propose it.

On Fri, Sep 10, 2010 at 12:37:12PM -0700, Don Stewart wrote:
> There needs to be a maintainer to take over mtl, or
> transformers/monads-*, with a roadmap for solving the diversity problem,
> and a proposal to put the result in the HP. Ideally without breaking
> things.

Someone needs to push this proposal, and I'm happy to do it.  After that,
I think these packages should be community managed, with changes via the
library submission process (as for mtl now).

There will be some breakage (two dozen packages in my most recent test).
I will work up a library+HP proposal.

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