9 Oct
2009
9 Oct
'09
10:45 a.m.
On Fri, 9 Oct 2009, Martijn van Steenbergen wrote:
Hallo café,
Can anyone think of datatypes that are Foldable but not Traversable?
If not, what is the purpose of having a separate Foldable class?
Recently I wondered, why Foldable is superclass of Traversable, since I have examples where 'traverse' makes sense, but 'fold' not. http://www.haskell.org/pipermail/libraries/2009-February/011361.html