From: Hal Fulton <hal9000@...>
Date: 2004-09-04T12:39:31+09:00
Subject: Re: Hashes and ordering

Markus wrote:
> Where are you going with this?  There seem to be three unrelated things
> here:

Well, I have been thinking along the lines of: What if we had a built-in
ordered indexable collection in Ruby?

> To see why this seems odd, let me recast your question in terms of
> arrays:
> 
> <analogy>

[snip]

Clever analogy, but you're presupposing an unordered arbitrarily indexable
collection. A hash, like our Hash, is inherently unordered, but I am
imagining a similar ordered data structure.

It's more like:

   x = [1,2]
   y = [2,1]
   x == y     # false - we *do* depend on this being false

I'm envisioning a data structure that has an order, but is otherwise (in
behavior, not implementation) like our current Hash.

I don't want to go into detail about what I'm thinking at the moment.

But I can see where my post was unclear or vague and would raise
very valid questions in your mind.


Hal