Proposal: Non-allocating way to iterate over a Data.Map: traverseWithKey_

Milan Straka fox at
Tue Jul 2 21:21:04 CEST 2013

Hi Edward,

> -----Original message-----
> From: Edward Kmett <ekmett at>
> Sent: 2 Jul 2013, 14:51
> This could be implemented very easily with an appropriate Monoid with
> foldMapWithKey. I put in a proposal for adding it (and a ticket on
> containers) that received a couple of +1s, but I confess I never followed
> up on it with Milan and Johan after the proposal period ended.

Oh, I completely forgot. I went through the last year's mailboxes and
found it. Merging now :)


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