MonadIO in mtl and transformers

Antoine Latter aslatter at gmail.com
Mon Dec 21 01:42:56 EST 2009


On Mon, Dec 21, 2009 at 12:27 AM, Michael Snoyman <michael at snoyman.com> wrote:
>
>
> On Mon, Dec 21, 2009 at 7:47 AM, Antoine Latter <aslatter at gmail.com> wrote:
>>
>> On Sun, Dec 20, 2009 at 11:03 PM, Michael Snoyman <michael at snoyman.com>
>> 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


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