From: Brett Williams <brett_williams@...>
Date: 2002-09-11T04:55:31+09:00
Subject: Re: Multi-level sort idiom?

Mike Stok wrote:

> In article <1031682194.811634@cswreg.cos.agilent.com>, Brett Williams
> wrote:
>> Let's say I have an array, each element of which is a 2-dimensional array
>> of ints.
>> 
>> I want to sort with the first element in the 2D array taking precedence,
>> but using the second as a tiebreaker.
[snip]
> You can use Numeric's nonzero? e.g.
> 
>   x = [[5, 1], [3, 2], [3, 3], [1, 5]]
>   x.sort { |a, b| (a[0] <=> b[0]).nonzero? || a[1] <=> b[1] }
> 
>     => [[1, 5], [3, 2], [3, 3], [5, 1]]

Thanks, that's what I was looking for.  Now I understand the behavior of 
Ruby's ||, &&, or, and and better too!

-- 
The key of strategy... is not to choose a path that leads to victory, but 
to choose so that all paths lead to a victory.
-- L.M. Bujold