Records in Haskell

[AntC]

Greg Weber <greg <at> gregweber.info> writes:

> 
> I looked at the DORF implementers view
> 
http://hackage.haskell.org/trac/ghc/wiki/Records/DeclaredOverloadedRecordFields
/ImplementorsView
> 
> It appears that we still have no solution for record updates that
> change the type of a polymorphic field.

There's two varieties of polymorphic fields:
- the type-changing variety
  DORF has a solution for update/changing the type of field and record
             (always has since the proof of concept in December)
  SORF has a speculative suggestion of Quasifunctor
            (looks like this needs tightening up??)
- the higher-ranked variety
  neither proposal has a way of updating
             (well, DORF did but it's an unscalable "hack" [SPJ],
              I put it on the wiki anyway, in case somebody can improve it)


AntC