Proposal: more general unionWith for Data.Map

[Johan Tibell]

On Tue, Jan 24, 2012 at 11:42 AM, Christian Sattler
<sattler.christian at gmail.com> wrote:
> I don't care much about the naming, but note that the analogous
> property already fails for the generalized intersectionWithKey in the
> development version.

I suspected as much. I think the current intersectionWithKey is
broken. We should have a single function, mergeWithKey, that allows
people to do the things they currently do using Maybe return values in
e.g. intersectionWithKey.

Cheers,
Johan