#15471: Polymorphism, typed splices and type inference don't mix -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Template Haskell | Version: 8.4.3 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 mpickering): The inferred type of `test_foo2` is exactly what you suggest it shouldn't be unless I am misunderstaning. {{{ *SP> :t test_foo2 test_foo2 :: forall {a}. Num a => Language.Haskell.TH.Syntax.Q (Language.Haskell.TH.Syntax.TExp (a -> a)) }}} The difference is now that you can't splice back in `test_foo2` without instantiating `a` as otherwise the ambiguous type variable stops `Num a` being solved. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15471#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler