#14111: strange error when using data families with levity polymorphism and unboxed sums and data families -------------------------------------+------------------------------------- Reporter: carter | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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 goldfire): I seem to recall this behavior being a deliberate design decision -- GADT constructor types stand alone. There was a long ticket with commentary and deliberations. Sadly, I can't find it, and 10 minutes of `git blame`-chasing in the area of code that should have been affected didn't find anything either. Perhaps SPJ remembers more. This kind of problem should always succumb to a kind annotation somewhere, but I agree that it's unfortunate and repetitive to put the annotation in. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14111#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler