#10755: Add `MonadPlus IO` and `Alternative IO` instances -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: task | Status: patch Priority: normal | Milestone: 7.12.1 Component: Core Libraries | Version: Resolution: | Keywords: report- | impact Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: Phab:D1148 -------------------------------------+------------------------------------- Comment (by ekmett): I think the ideal situation would be to have `transformers` continue to export those instances conditional on the version of `base`. This would ensure that the maximal number of versions of `base` work with the maximal number of versions of `transformers`, rather than inducing an unneeded gate function on what works with what. These sorts of gotchas are the things that drive away users, so it is worth spending the time to get this right. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10755#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler