27 Mar
2015
27 Mar
'15
6:23 a.m.
On Fri, Mar 27, 2015 at 01:03:04PM +0900, Fumiaki Kinoshita wrote:
It is well known that ListT m in transformers is not a monad unless the underlying monad is commutative. The fact that ListT is not a monad transformer is sufficient to remove it from the package, and several packages already defined their own ListT.
Oughtn't we deprecate ListT or replace it by a correct one?
This flaw is at least documented, and it does severely limit the usefulness of ListT. Deprecation seems reasonable, but we'd need to offer a replacement first.