Re: Data.Map.updateAt problem

Andriy Palamarchuk wrote:

I'm currently improving Data.Map documentation. Behavior of updateAt in this module differs from what I would expect. [Snip example of updateAt dropping parts of the map]

That's a bug. In essence, updateAt only works if the root node of the tree encoding the map is updated; in all other cases it throws away parts of the tree. See the attached patch for a fix. (The patch is agains the base package.) Bertram