From: Michael H Buselli <eholgnyx@...>
Date: 2004-09-09T04:13:48+09:00
Subject: Re: OK... :) question about hash and array literals

On Mon, 06 Sep 2004 13:10:12 +0900, Ara.T.Howard@noaa.gov wrote:

> On Mon, 6 Sep 2004, Yukihiro Matsumoto wrote:
> 
> > Hmm, I thought hash order would be ignored always for compares.
> > Optional use of order is an interesting idea, although I want better
> > looking API than
> >
> > | {1=>2, 3=>4}.ordered != {3=>4, 1=>2}.ordered
> 
> this is a GREAT idea!  i've always thought that there is no reason hashes
> could not simply remember the order of inserts and use it.  as far as
> comparisons i would agree they should not be ordered in general, perhaps
> 
>    hash.identical other
> 
> or something that did depend on order.  one of the coolest things about
> ordered hashes would be their use with yaml!  i use yaml configs and the lack
> of hash ordering is a constant pain in my side.  how difficult do you think i
>-t
> would be to add order memory for hash insert operations and to use it for
> each/map, etc.?

Sounds like a new data type to me.  I frequently find myself doing
things like this:

    @some_data_by_index = Hash.new
    @some_data_order = Array.new

and then I manage the two variables together for any insertion I make
into the data:

    @some_data_by_index[value.key] = value
    @some_data_order.push value

So what if there was an ArrayAndHash?

    @some_data = ArrayAndHash.new(:key)
    @some_data.push value

Such a thing would need some semantics of both an Array and a Hash, and
I don't feel like figuring out what they should look like right now.
Maybe next time I need such a thing I'll think about it more.

Similar things have been discussed on the list before, but I don't know
if anything became of them.

T\_/T\_/T
Michael H Buselli <eholgnyx@cosine.org>
"If you give a man a phish, he has a stolen credit card for a day.  If
 you teach a man to phish, he will eat three square meals daily for a
 lifetime; perhaps served from behind bars, but he will not go hungry."