From: Dave Vandervort <irving_1@...>
Date: 2001-08-31T12:01:15+09:00
Subject: [ruby-talk:20595] Re: ordered hash

> 
> I just stumbled upon this implementation as I looked through httpmail-ruby:
> 
> class OrderedHash < Hash
>         alias_method :store, :[]=
>         alias_method :each_pair, :each
> 
>         def initialize
>                 @keys = []
>         end
> 
>         def []=(key, val)
>                 @keys << key
>                 super
>         end
> 
>         def delete(key)
>                 @keys.delete(key)
>                 super
>         end
> 
>         def each
>                 @keys.each { |k| yield k, self[k] }
>         end
> 
>         def each_key
>                 @keys.each { |k| yield k }
>         end
> 
>         def each_value
>                 @keys.each { |k| yield self[k] }
>         end
> end
> 
> --
> Ryan Tarpine, rtarpine@hotmail.com
> "Technology is a queer thing.  It brings you great gifts
> in one hand, and it stabs you in the back with the other."
>          -- C.P. Snow

Very nice. I remember thinking earlier on this thread that automatically
sorted keys would be useful, too. That gives us this:

class SortedHash < OrderedHash

	def []=(key, val)
		super
		@keys.sort!
	end
end

Thanks.

irv