On Sun, Dec 20, 2009 at 11:03 PM, Michael Snoyman wrote:

Of course, I won't complain if someone just fixes the mtl/transformers mess itself ;).

Yes, that's the other valid solution. My request has been documented on GHC Trac in bug 3777: http://hackage.haskell.org/trac/ghc/ticket/3777 Antoine

On Mon, Dec 21, 2009 at 12:27 AM, Michael Snoyman wrote:

On Mon, Dec 21, 2009 at 7:47 AM, Antoine Latter wrote:

...

On Sun, Dec 20, 2009 at 11:03 PM, Michael Snoyman wrote:

...

Of course, I won't complain if someone just fixes the mtl/transformers mess itself ;).

Yes, that's the other valid solution.

My request has been documented on GHC Trac in bug 3777: http://hackage.haskell.org/trac/ghc/ticket/3777

Antoine

Is there any reason to export only MonadIO? MonadTrans seems like a good candidate for that split as well.

Michael

I guess I've never need the 'lift' function outside of code which used other bits of the mtl, so I did not export it. I'm struggling to come up with a concept which would unify a package containing both the MonadIO class and the MonadTrans class. The mtl made sense, as it contained shed-loads of other classes. Antoine

On Mon, Dec 21, 2009 at 12:09 PM, wren ng thornton < wren@community.haskell.org> wrote:

Antoine Latter wrote:

...

Michael Snoyman wrote:

...

Is there any reason to export only MonadIO? MonadTrans seems like a good candidate for that split as well.

I guess I've never need the 'lift' function outside of code which used other bits of the mtl, so I did not export it.

I'm struggling to come up with a concept which would unify a package containing both the MonadIO class and the MonadTrans class. The mtl made sense, as it contained shed-loads of other classes.

Maybe it'd be worth just rolling into base, instead of a separate package? Both MonadTrans and MonadIO seem as basic to me as MonadPlus. And I don't recall there ever being controversy about the design of either class. (Moving them to base may mess up folks using new base + old mtl ...but that seems fixable by forcing old+old or new+new.)

-- Live well, ~wren

By the way, does anyone have an update on where we stand wrt the mtl/transformers situation?

Michael