From: Cameron McBride <cameron.mcbride@...>
Date: 2006-03-10T01:18:03+09:00
Subject: Re: nuby question: sorting with nils

On 3/9/06, Toby DiPasquale <toby@cbcg.net> wrote:
> Speaking of this very topic, I am having an issue where I want to sort
> objects by two of its attributes in a SortedSet, but its not working
> out:
>
> I'd like it to be sorted first by its :a attribute, but if they are
> equal, by whatever sorting on the :b attributes comes up with.

as a quick alternative, sorting by several attributes is pretty easy
using #sort_by

  X = Struct.new :a, :b
  s = []
  s << X.new(3, 3)
  s << X.new(3, 4)
  s << X.new(1, 2)
  s << X.new(4, 8)
  s << X.new(4, 2)
  sorted = s.sort_by { |a| [a.a,a.b] }
  sorted.each { |v| p v }
  #<struct X a=1, b=2>
  #<struct X a=3, b=3>
  #<struct X a=3, b=4>
  #<struct X a=4, b=2>
  #<struct X a=4, b=8>

Cameron