From: w_a_x_man <w_a_x_man@...>
Date: 2010-11-08T03:20:13+09:00
Subject: Re: sort_by is not stable ?

On Nov 7, 4:22 am, Michel Demazure <mic...@demazure.com> wrote:
> sort_by  is not a stable sorting method (ruby 1.9.2 p0)
>
> I am doing word statistics in a text file. I have a long array of
> entries [word, number], sorted by alphabetic order on word. When I sort
> on number, entries with the same number are shuffled.
>


I've noticed that it's unstable under 1.8.7:

%w(foo bar car war raw rat cat or bat is).sort.
sort_by{|s| s.size}
    ==>["is", "or", "bar", "cat", "foo", "car", "bat", "rat", "raw",
"war"]
VERSION
    ==>"1.8.7"