From: Trans <transfire@...>
Date: 2005-04-08T03:44:39+09:00
Subject: help traversing and modifying hash key and value inplace

Having a little trouble here. seems that I'm getting some errors trying
to dup certain values (like FIXNUM), or if I try clone it says that I
can't modify a frozen string. Is there a way to achieve this
functionality? Here's the code:

 class Hash

   # Returns a new hash created by traversing the hash and its
   # subhashes, executing the given block on each key/value pair.
   #
   #   h = { "A"=>"A", "B"=>"B" }
   #   h = h.traverse { |k,v| k.downcase! }
   #   h  #=> { "a"=>"A", "b"=>"B" }
   #
   def traverse( &yld )
     h = {}
     self.each_pair do |k,v|
       q = k.dup
       f = v.dup
       if f.kind_of?(Hash)
         h[q] = f.traverse( &yld )
       else
         yield(q, f)
         h[q] = f
       end
     end
     return h
   end

 end


Thanks,
T.