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