From: "Iñaki Baz Castillo" <ibc@...>
Date: 2011-07-02T00:50:46+09:00
Subject: Re: How to order Structs based on two fields

2011/7/1 Su Zhang <su.comp.lang.ruby@gmail.com>:
> The efficiency depends on how expensive it is to compute the key of the
> elements. If the computation is non-trivial, then Array#sort_by would be
> much faster because it caches the keys before the sort so that no
> unnecessary computation is done (i.e., the key of each element is computed
> exactly once).
>
> If, like it is in your case, the computation only involves several Fixnum
> comparisons, Array#sort_by will most likely be slower as it needs to
> allocate (cache) the key set prior to the actual sorting.
>
> For example, there should be a difference if the accessors themselves are
> expensive. Something like:
>
>  def a
>    sleep 0.01
>    @a
>  end

Thanks. However in my case the class is a Struct and I add no
complexity to accessor. In fact I just use:

  KK = Struct.new(:a, :b)
  kk1 = KK.new(10,20)

-- 
Iñaki Baz Castillo
<ibc@aliax.net>