From: Vladimir Dozen <Vladimir.Dozen@...>
Date: 2002-03-13T22:27:06+09:00
Subject: key comparision inside Hash

ehlo.

   A few Q's:

   1. Where can I get information on Ruby's garbage collector algorithms?
      Where can I get "internals" info on Ruby in general?

   2. How should I change the following code to get my object back from
      Hash?

=====================
class Key
   include Comparable

   def initialize(a,b)
     @a = a
     @b = b
   end

   attr_reader :a, :b

   def <=> (another)
     @a <=> another.a || @b <=> another.b
   end
end

hsh = Hash.new
key1 = Key.new(1,2)
key2 = Key.new(1,2)

# the keys are considered equal, but...
hsh[key1] = "hello"
print "Value by separate key:",hsh[key2],"\n"
=====================

   I always get nil. Being C++ programmer, I expected comparision
   operator will be used to match the keys inside hash; I was wrong?

dozen