#13524: GHC does not preserve order of forall'd vars with TypeApplications -------------------------------------+------------------------------------- Reporter: crockeea | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: | Keywords: | TypeApplications 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 simonpj):
Perhaps even better, we could label variables in partial type signatures as "inferred", meaning that GHC will prevent them from being available for type application.
Yes! After all, if you write {{{ f :: forall a. _ -> a -> a f = ... }}} you might end up with more type variables; e.g. f's signature might really be {{{ f :: forall a b c. (b,c) -> a -> a }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13524#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler