#11066: Inacessible branch should be warning - otherwise breaks type soundness? -------------------------------------+------------------------------------- Reporter: rrnewton | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #8128, #8740 | Differential Rev(s): Phab:D1454 Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
Here's a much smaller reproduction of what I suspect is going on in Edward's code
I don't see the problem here. As stated, `Gcd` is a nullary type function, so it's definitely the case that `1 :~: Gcd 3 4` is unsatisfiable, so `foo` cannot be called. Why is it wrong for GHC to complain. I'm really lost in this ticket. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11066#comment:26 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler