From: Harry Ohlsen <harryo@...>
Date: 2003-08-06T10:17:44+09:00
Subject: Re: What's New and Shiny in Ruby 1.8.0?

why the lucky stiff wrote:

> My 1.8.0 summary is up at:
> 
>   http://whytheluckystiff.net/articles/2003/08/04/rubyOneEightOh
> 
> I'm about halfway done.  I'll post a link again when I feel like I'm
> finished.

One thing mentioned there is the new sort_by in Enumerable.  A simple example I tried is:

  text = ["the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"]

  puts text.sort_by { |x| x.length }.inspect

  #=> ["the", "the", "fox", "dog", "over", "lazy", "quick", "brown", "jumps"]

Something that's not mentioned, but I figured I'd try it, because I thought it would be nifty, is sorting by multiple values ...

  text = ["the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"]

  puts text.sort_by { |x| [x.length, x] }.inspect

  #=> ["dog", "fox", "the", "the", "lazy", "over", "brown", "jumps", "quick"]

Ie, we now have the values sorted first by their length, and when the length is the same, they're sub-sorted by the text itself.  I think that's great!

This would be particularly useful if the data items in the enumeration were instances of more complex objects. Then, you could do things like:

   sorted = people.sort_by { |p| [p.last_name, p.first_name, p.salary] }

I just love Ruby!