From: Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand>
Newsgroups: comp.lang.java.programmer
Subject: Re: Binary Search
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Date: Sun, 03 Apr 2011 12:40:08 +1200
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In message <in7h0u$apu$1@dont-email.me>, Mike Schilling wrote:

> "Leif Roar Moldskred" <leifm@dimnakorr.com> wrote in message
> news:PtmdncL-dvk-3wrQnZ2dnUVZ876knZ2d@telenor.com...
>
>> Mike Schilling <mscottschilling@hotmail.com> wrote:
>>>
>>> For a SortedMap, specify a Comparator that knows.
>>
>> Eh? How is that going to give you a key?
> 
> It's going to give you an ordering for the binary search.

The Python folks discovered this the hard way: providing a comparator 
callback is slow. It’s better to provide a key-accessor callback, and let 
the sort algorithm do the comparison.