From: Michael Neumann <mneumann@...>
Date: 2004-12-14T02:02:37+09:00
Subject: Hash freezes String keys are returns copy

Hi,

My observation is, that Hash behaves differently for different kinds of 
objects. While an Object key is preserved as is, a String key isn't 
(it's frozen and a copy is returned)! I'd like to get back my original 
key from a Hash, but with String keys this is not possible.

   a = 'test'
   b = Object.new

   h = {}
   h[a] = a
   h[b] = b

   h.each do |k,v|
     puts "key: "
     p k
     p k.object_id
     p k.frozen?

     puts "value: "
     p v
     p v.object_id
     p v.frozen?
   end

The result is (indented for readability):

key:
   #<Object:0x81f239c>
   68129230
   false
value:
   #<Object:0x81f239c>
   68129230
   false

key:
   "test"
   68135310
   true
value:
   "test"
   68135320
   false


Is this intended behaviour?

So in my case, instead of { obj => data }, I now have to store
{ obj => [obj, data] }, as I can't get the original object "obj" back.

Regards,

   Michael