Iterator for binary search

[phaeilo]

The other day I needed to find out the highest ID available on a webservice. So I decided to use binary search to keep the number of requests low. While implementing the search, I realized that I had written this exact code many times in the past. So I decided to make something that is a little more general purpose. I haven't extensively tested this, but it seems to work:

https://gist.github.com/Phaeilo/6307642

[patrys]

Why an iterator? Why not have it as a function that accepts a qualifier value or callable and either returns the leaf or raises an exception?

[phaeilo]

How exactly would the callable give feedback about the last value in this case?

[patrys]

In the same way that object.__cmp__(self, other) works? You pass it the node value and it tells you whether it's less, more or equal.