#7066: isInstance does not work for compound types ------------------------------+--------------------------------------------- Reporter: edsko | Owner: Type: bug | Status: new Priority: normal | Component: Template Haskell Version: 7.4.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Testcase: Blockedby: | Blocking: Related: | ------------------------------+--------------------------------------------- Consider
{{{ import Language.Haskell.TH.Syntax data A = A test :: Q [Dec] test = do tp <- [t| (Int, A) |] inst1 <- isInstance ''Show [ tp ] runIO $ print inst1 return [] }}} This prints True even though there is no Show instance for A (the Show instance it finds is for pairs, but it does not verify that there are Show instances for the pair components). -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7066> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs