haskell/containers — pull request #26 by bgamari (2013-04-15 20:55:18+00:00)
Title: Add `divide` function to `IntMap`

The tree structure used by `IntMap` enables one to very easily divide an `IntMap` into two halves of roughly equal size. This can be a very useful operation (e.g. splitting a B-tree node). This function (the name of which is up for discussion) exposes this functionality. This could also be done for `IntSet`.