13 Mar
2009
13 Mar
'09
12:28 p.m.
On Sat, Mar 14, 2009 at 02:12:45AM +1000, Matthew Brecknell wrote:
Ross Paterson wrote:
No. Choose an arbitrary element shape :: f () and define point x = fmap (const x) shape
Interesting. Is the arbitrariness of the shape some sort of evidence that Pointed is not really a very useful class in its own right?
Not useless, but equivalent to class Functor f => Pointed f where unit :: f () Naturality of point does the rest. But not all definitions of unit are equally useful.