From: Robert Evans <robert.evans@...>
Date: 2004-10-06T16:43:05+09:00
Subject: Fixnum <=> confusion

Hi,

I am recently learning Ruby, and came across an interesting problem 
that I do not understand. I was trying to count how many times the sort 
method was called on an object by overridding <=> to count the number 
of calls.

I decided to extend Fixnum as follows, but it didn't work. Can anyone 
tell me why? Thanks.

Bob Evans


Code:

class Fixnum

    @@count = 0

    alias originalComparator <=>

    def <=>(o)
      @@count += 1
      originalComparator(o)
    end

    def Fixnum.count
      @@count
    end
end

Running against it:

 >array = [5, 4, 3, 2, 1]
=> [5,4,3,2,1]

 >array.sort
=> [1,2,3,4,5]

 >Integer.count
=> 0

Expected => 6 > result > 0

Now, if I call 1<=>2 then count increments. Does this mean that Fixnum 
sorting does not call those operators? Thanks for any help.