Records in Haskell

[AntC]

Ian Lynagh <igloo <at> earth.li> writes:

> 
> > * an extra arg to Has (how does the constraint sugar cope?)
> 
> You can infer ft from the f.
> 

Let me explain better what I mean by "two private namespaces", then we'll try 
to understand how your proposal goes ...

  module T             where
      data FieldT = Field
      data RecT = RecT{ Field :: Int }
      ...
  module U             where
      data FieldU = Field
      data RecU = RecU{ Field :: Bool }
      ...
  module V             where
      import T                             -- also consider either/both
      import U                             -- imports hiding (Field)
      data RecV = RecV{ Field :: String }  -- am I sharing this Field?
                                           -- who with?
      ...
      ... r.Field ...           -- is this valid?, if not what is?
      ... r{ Field = e }        -- likewise

(Oh yeah, imports and hiding: how do I do that for these non-String-type-Kinds?
And is this allowed?:
      data NotaField = Constr Int Bool
      data AmIaRec = AmI{ Constr :: String }
      ...
      ... r.Constr ...

It's all getting very tangled trying to squeeze constructors into other roles.)


AntC