Records in Haskell
AntC
anthony_clayden at clear.net.nz
Tue Feb 28 09:36:57 CET 2012
wren ng thornton <wren <at> freegeek.org> writes:
>
> I'm not sure that I like the current proposals for how to control the
> non/automatic-ness of polymorphism (for reasons I can spell out later,
> if desired). But we definitely want to have something that's a bit more
> cultured than simply making all record projectors polymorphic over records.
>
Wren, I'm not sure if you've got it straight. (It's a subtle issue.) This is
an area where SORF differs from DORF:
- SORF can't hide the representation of a given field name
(so a client program can 'guess' a field "identifier")
That's because SORF is driven by String Kind, which cannot be scope
controlled.
- DORF uses (Proxy) types for (roughly) the same purpose as the String Kinds.
But because they're types, you can control the scope, and keep the
abstraction.
AntC
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