From: Hal Fulton <hal9000@...>
Date: 2006-08-25T07:52:46+09:00
Subject: Re: Call for crystalization --was:A use case for an ordered hash

Pit Capitain wrote:
> 
> Sven, regarding the "HistoryHash" part of your post:
> 
> In order to replace the standard Hash with a "better" Hash, there should 
> be a clear agreement on its desired behaviour. I don't think this 
> agreement has been achieved yet. What should be the result of the 
> following code?
> 
>   hh = HistoryHash.new
>   hh[:one] = 1
>   hh[:two] = 2
>   hh[:one] = 3
>   hh.each do |k, v| p k end
> 
> Should it be
> 
>   :one
>   :two
> 
> or
> 
>   :two
>   :one
> 
> Why should it be the one or the other?

An excellent point, and there are other similar questions
to be answered.

As for replacing Hash with another implementation, I would
be OK with it (if it proved reasonably speedy).

Others would not want it even if it were the same speed
as before.

I think the people calling for an ordered hash are a sizable
group, but still a minority.


Hal