From: cruiserdan <dan@...>
Date: 2007-12-07T07:30:07+09:00
Subject: Re: sorting Array of accentuated Strings

On Dec 6, 11:36 am, unbewusst.s...@weltanschauung.com.invalid (Une
Bévue) wrote:
> I've done a "self <=> anotherString" comparaison which works by itself :
>
> class String
>   def <=>( aString )
>     [blahblahblah]
>   end
> end
>
> however if i want to sort an Array of Strings, the Array is sorted as
> usual within Ruby (put accentuated characters at the end) :
>
> a = [ "Être", "Fenêtre", "Etre" ]
>
> b = a.sort { | i, j | i <=> j }
> puts "b = [ " + b.join(", ") + " ]\n"
> # => b = [ Etre, Être, Fenêtre ]
>
> c = a.sort  #<=>( aString ) NOT CALLED...
> puts "c = [ " + c.join(", ") + " ]\n"
> # => c = [ Etre, Fenêtre, Être ]
>
> Why, in the case of "c = a.sort", #<=>( aString ) isn't called ?
> the comparaison within an Array could compare different kind of objects
> like :
>
> a = [ 0, "a", 9, Time.new ] ???
>
> --
> Une Bévue

I believe that the C implementation Array#sort checks for a String
argument and calls the C string comparison operator directly in that
case. See:

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi/trunk/array.c?view=markup

under the code for sort_2.

You might be interested in using some of the emerging Unicode support
in Ruby. Ruby 2 will have it built-in and there are several libraries
out there, although I don't have any experience using them.

Regards,
Dan Yoder
http://dev.zeraweb.com/