Trees that Grow and constraints

Alan & Kim Zimmerman alan.zimm at gmail.com
Mon Nov 13 12:48:49 UTC 2017


> So why not use one?
>
>
>
> Simon
>
>
If I do

    instance (Data p) => Data (Experiment p)

then GHC does not know that the type instances for


     type instance XEOverLit (GhcPass 'Parsed     ) = PlaceHolder
     type instance XEOverLit (GhcPass 'Renamed    ) = PlaceHolder
     type instance XEOverLit (GhcPass 'Typechecked) = PlaceHolder

apply.

Or do I misunderstand your advice?

Alan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20171113/d717dd54/attachment.html>


More information about the ghc-devs mailing list