#14135: PatternSynonyms regression in GHC HEAD (expectJust mkOneConFull) -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: carlostome Type: bug | Status: new Priority: highest | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D3981 Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): This type-of-scrutinee check is interesting, but it would come at a cost. Currently, it is quite possible to use `Foo1` and `MyFoo2` together, in this function: {{{#!hs g :: Foo Int -> Int g (Foo1 x) = x g (MyFoo2 y) = y }}} But if we adopted your proposed type-of-scrutinee validity check, then we'd no longer be able to write a `COMPLETE` program that covers this use case, since `{-# COMPLETE Foo1, MyFoo2 #-}` wouldn't typecheck. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14135#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler