#10457: Revise/remove custom mapM implementation for lists -------------------------------------+------------------------------------- Reporter: dolio | Owner: Type: task | Status: new Priority: normal | Milestone: 7.10.2 Component: libraries/base | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D924 -------------------------------------+------------------------------------- Comment (by dolio): I'm not really attached to this, so if simonmar is okay with postponing to 7.12, it's fine with me. Anyone who uses `Monad`s with `(<*>) /= ap` (at least, in ways giving distinct answers) is going to have a bad time, though. The specification of `Monad` now says they need to be equivalent, and I think that gives library writers license to switch between them without making a major version change. And it's only going to get worse. When ApplicativeDo gets implemented, using that extension will silently switch between these things. For instance, if ApplicativeDo were on in the file with the custom `mapM`, it would already be the same as `traverse`, I think. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10457#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler