[Haskell-cafe] Haskell's "historical futurism" needs better writing, not better tools

Tom Ellis tom-lists-haskell-cafe-2017 at jaguarpaw.co.uk
Fri Oct 1 09:05:30 UTC 2021


On Thu, Sep 30, 2021 at 09:14:36PM -0400, Viktor Dukhovni wrote:
> > In fact all class methods have simple semantic definitions in terms of 
> > the same named functions from Data.List via 'toList'.
> 
> But performance may differ radically, and `toList` may diverge for
> `snocList` when infinite on the left, though that's a rather
> pathological example.

If one can't write Foldable-generic functionality in a way that
provides some reasonable uniformity of performance over different
instances then one wonders what is point of having Foldable as a
typeclass at all.  At that point it's just name overloading.

Tom


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