#13069: hs-boot files permit default methods in type class -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.1 checker) | Keywords: backpack hs- Resolution: | boot Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by ezyang): Actually, the bug is worse: the following A.hs-boot file is accepted by GHC. {{{ module A where class C a where f :: a -> a f = True }}} This doesn't seem to be a soundness problem because what this actually seems to translate into "there is a default method for f", so this code never gets compiled / used for anything. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13069#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler