#13058: Use coercions to implement fmapDefault and foldMapDefault -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: task | Status: new Priority: normal | Milestone: 8.2.1 Component: Core | Version: 8.0.1 Libraries | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- We should be able to use {{{#!hs fmapDefault :: Traversable t => (a -> b) -> t a -> t b fmapDefault = (getId .) #. traverse .# (Id .) foldMapDefault :: (Traversable t, Monoid m) => (a -> m) -> t a -> m foldMapDefault = (getConst .) #. traverse .# (Const .) }}} where `.#` and `#.` are coercion operators found in `Data.Profunctor.Unsafe`. This should help when the function passed in doesn't inline. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13058 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler