#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 -------------------------------------+------------------------------------- Changes (by RyanGlScott): * cc: ross (added) Comment: While I don't want to cause unnecessary pain for users, I have to wonder about the placement of the instances in `transformers`. Currebtly, they're located in `Control.Monad.Trans.Error`, which has been deprecated for a while. If users want to backport these new `IO` instances in their code, they'll have to reach for a module which GHC will warn is deprecated, which doesn't feel satisfying. Perhaps we could move the orphan instances to a different module in `transformers`, reexport it from `Control.Monad.Trans.Error`, and tell users to use the new module from here on out for conpatibility purposes? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10755#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler