Re: 8.2.1: Ord TyCon is gone?

29 Jul 2017

      Levent Erkok  writes:
...
I'm trying to port some plugin code from GHC 8.0.2 to GHC 8.2.1; alas I'm
getting an error suggesting that TyCon is no longer an instance of Ord:
Data/SBV/Plugin/Analyze.hs:580:33: error:
    • No instance for (Ord TyCon) arising from a use of ‘M.lookup’
      There are instances for similar types:
        instance Ord GHC.Types.TyCon -- Defined in ‘GHC.Classes’
    • In the expression: k `M.lookup` tcMap
      In the expression:
        case k `M.lookup` tcMap of
          Just knd -> return knd
          Nothing -> unknown
      In a case alternative:
          Just k
            -> case k `M.lookup` tcMap of
                 Just knd -> return knd
                 Nothing -> unknown
    |
580 |                  Just k -> case k `M.lookup` tcMap of
    |                                 ^^^^^^^^^^^^^^^^^^
Hmm. I am unable to reproduce this,

    $ ghci
    λ> import Type.Reflection
    λ> let tc = typeRepTyCon (typeRep @Int)
    λ> tc == tc
    True

Does that work for you?

Cheers,

- Ben

Re: 8.2.1: Ord TyCon is gone?

Ben Gamari