#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: 13737 | Blocking: Related Tickets: #14457 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Ryan, what happens if you try this example in your patch: {{{#!hs type S = T data T where MkT :: Int -> S }}} That works today. But I have a feeling it will fail with your patch. The problem is actually an oversight in Phab:D4974, but I was surprised that Phab:D4974 actually accepts the program above. However, a sneaking suspicion is that, with your patch as well, the program will be rejected. I'm wondering if I should bother fixing this (maybe it wasn't an oversight after all), and so I'm curious to know the behavior on your branch with that program. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14111#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler