From: Austin Ziegler <halostatue@...>
Date: 2006-08-15T02:01:29+09:00
Subject: Re: A use case for an ordered hash

On 8/14/06, gwtmp01@mac.com <gwtmp01@mac.com> wrote:
> Can't you just maintain an internal array representing the key insertion
> order?  Something like:
>
> class OHash < Hash
>    # ...
>    def each
>       keyseq.each { |k| yield k, self[k] }
>    end
> end
>
> Where keyseq is just an array that is updated whenever keys are
> added/deleted?

It's a little more complex than that, but that's pretty much what all
existing implementations do. We're talking about wanting a way of
having an ordered associative list (that defaults to insert ordering,
but can be changed to a sorted ordering, perhaps) in the Ruby core
language *with a literal constructor*, because there is value for it.

-austin
-- 
Austin Ziegler * halostatue@gmail.com * http://www.halostatue.ca/
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               * austin@zieglers.ca