#8968: Pattern synonyms and GADTs ----------------------------------------------+---------------------------- Reporter: kosmikus | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: Resolution: | 7.8.1-rc2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by kosmikus): Oh, I forgot. What does this then imply for explicit type signature on pattern synonyms? Do you propose to still allow {{{ pattern D :: a -> T (Maybe a) b pattern D x = MkT (Just x) }}} (arguing that the "expression type" is easy to infer) or should the user also be forced to write {{{ pattern D :: (b ~ Bool) => a -> T (Maybe a) b pattern D x = MkT (Just x) }}} ? I think the latter would certainly be more consistent then? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8968#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler