14 Aug
2011
14 Aug
'11
2:21 p.m.
On Sun, 2011-08-14 at 21:05 +0300, Yitzchak Gale wrote:
Brandon Allbery wrote:
Anything useful has to be modified to depend on SemiGroup as well to get mconcat or its replacement; that's why you jumped the proposal to begin with....
Not at all. Types with Monoid instances need an additional instance, a Semgroup instance
That does require depending on semigroups though, and I think that's what Brandon was saying. Of course, the obvious solution to this would be to promote semigroups, e.g., by adding it to the Haskell Platform or including it in base... but the current semigroups package is a bit heavyweight for that; it exports four new modules for what is really a very simple concept! -- Chris Smith