#15305: Erroneous "non-exhaustive pattern match" using nested GADT with strictness annotation -------------------------------------+------------------------------------- Reporter: jkoppel | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Research Component: Compiler (Type | needed checker) | Version: 8.4.3 Resolution: | Keywords: | PatternMatchWarnings Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D5087 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => patch * differential: => Phab:D5087 Comment: Implementing a naïve `NonVoid(ty)` solver ends up being pretty darn simple: just check if there is at least one inhabitation candidate for `ty` (as determined through `inhabitationCandidates`) such that its term and type constraints are satisfiable. That's sufficient to avoid warnings in the original program and in the program in comment:4. See Phab:D5087. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15305#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler