[Haskell-cafe] closed world instances, closed type families
lemming at henning-thielemann.de
Wed Apr 3 01:30:28 CEST 2013
On Tue, 2 Apr 2013, Daniel Peebles wrote:
> It seems very similar to Ryan Ingram's post a few years back
> (pre-TypeNats): http://www.haskell.org/pipermail/haskell-cafe/2009-June/062690.html
> The main difference is that he introduces the "knowledge" about zero vs. suc as a constraint, and you introduce
> it as a parameter. In fact, his induction function (which is probably what I'd call it too) is almost identical
> to your switch.
The answer to his post by Miguel Mitrofanov contains a caseNat that is
exactly my 'switch'. I see I am four years late.
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