#13153: Several Traversable instances have an extra fmap -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: dfeuer Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Core Libraries | Version: 8.1 Resolution: | Keywords: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): If only we had `mapTraverse` instead of `traverse` as the class method, none of this mess would be necessary. That would obviously be a hard sell for backwards compatibility. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13153#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler