#8503: New GeneralizedNewtypeDeriving check still isn't permissive enough -------------------------------------+------------------------------------ Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by nomeata): I was conservative when disallowing recursive newtypes for `Coercible`, but quite possibly too conservative. I also wanted to keep the code simple (Note that it just keeps generating constraints and passing them back to the constraint solver; it does *not* build the whole coercion in one go). I wasn’t aware of `TyCon.checkRecTc` and I’ll look into it. Thanks for pointing that out. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8503#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler