#13026: RFC functions for sums and products -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): Here is an interesting one, witnessing the isomorphism between `Sum Identity` and [https://hackage.haskell.org/package/transformers-0.3.0.0/docs/Control- Applicative-Lift.html Control.Applicative.Lift.Lift] {{{#!hs toLift :: Sum Identity g ~> Lift g toLift = \case InL (Identity a) -> Pure a InR ga -> Other ga }}} if it ever gets added to ''base''. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13026#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler