#12466: Typechecker regression: Inaccessible code in a type expected by the context -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): To clarify, I think the `constraints` code is an occurrence of the same bug since 1. `dividesGcd`'s type signature has a context (`Divides a b`, which is the same as `a ~ Gcd a b`) in which GHC determines an equality is unattainable. 2. The body of `dividesGcd` doesn't use the context, since it's defined in terms of `axiom` (a.k.a. `unsafeCoerce`). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12466#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler