From: Robert Klemme <bob.news@...>
Date: 2005-11-24T21:37:25+09:00
Subject: Re: Fixnum <=>

v.nainar wrote:
> I may be missing something obvious . Why  is the '<=>' operator not
> called  when there is no block supplied to sort ?.The Pickaxe book
> says ( apropos  Array.sort ):
>   " Comparisons for the sort will be done using the <=> operoator OR
>      using an optional  code block"
> How is the comparison done in the  second case ?
> 
> class   Fixnum
>   alias oldcmp <=>
>   def <=>(other)
>     puts " <=> called with #{self} and #{other} "
>     oldcmp(other)
>   end
> end
> 
> p  [9,1,7,3,5].sort { |a, b| a <=> b}
> p  [99,11,77,33,55].sort
> 

AFAIK it's an internal optimization.

    robert