Names for general merge tactics in Data.Map

[Henning Thielemann]

On Sat, 20 Aug 2016, David Feuer wrote:

> Argh! It probably actually is possible to emulate generalMergeA using 
> mergeWithKey, although it won't be pretty. I'll see if I can work up a 
> compat package in case someone needs one, but that probably won't happen 
> before the next containers release.

I do not use the GHC API, so far. If this is the only problem I would try 
to install a new containers additionally to the global one.