Re-use `transformers`'s `MaybeT` rather than our own
authorHerbert Valerio Riedel <hvr@gnu.org>
Mon, 7 Dec 2015 16:32:23 +0000 (17:32 +0100)
committerHerbert Valerio Riedel <hvr@gnu.org>
Mon, 7 Dec 2015 16:33:34 +0000 (17:33 +0100)
commit09333313f32be975faf9158fcd3648489d78ad82
treef7c044e07058a7aa6bdcd9f07d6323ffeb624716
parent04e1c27943503f2e12b009b91f7bef195766f6d0
Re-use `transformers`'s `MaybeT` rather than our own

The now removed `MaybeT` type was originally added back in 2008
via bc845b714132a897032502536fea8cd018ce325b

Reviewed By: bgamari

Differential Revision: https://phabricator.haskell.org/D1583
compiler/utils/Maybes.hs