#12072: GHC panic on type wildcard in left-hand side of data family -------------------------------------+------------------------------------- Reporter: andreash | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: fixed | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => fixed Comment: Thanks. This is OK in HEAD (and I hope 8.0). Wildcards are explicitly allowed on the LHS of type/data family instances. See the [http://downloads.haskell.org/~ghc/master/users-guide/glasgow_exts.html #data-instance-declarations user manual Section 9.9.1.2]. You are right that it's a bug in 7.10.3. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12072#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler