#5633: TypeFamilies don't seem to play with LIberalTypeSynonyms ----------------------------------------+----------------------------------- Reporter: ocharles | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.0.4 Resolution: invalid | Keywords: TypeFamilies LiberalTypeSynonyms Testcase: | Blockedby: Difficulty: | Os: Linux Blocking: | Architecture: x86 Failure: GHC rejects valid program | ----------------------------------------+-----------------------------------
Comment(by ocharles): Hi simon, thanks for the explanation. It's a shame that it can't work, as a newtype doesn't really cut it. Fwiw, the motivation of this ticket came from trying to abstract away Record declarations in HaskellDB with code that also uses type families. HaskellDB uses either `RecCons FieldType (Expr RetType)` or `RecCons FieldType RetType` depending on how a record is used/returned, and there doesn't seem to be a way to capture this with a type family, where I was trying to abstract Expr :: * -> * away. However, this ticket isn't the right place for that discussion, so I'll move that to a mailing list :) -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5633#comment:2> 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