From: Hal Fulton <hal9000@...>
Date: 2006-08-13T08:45:54+09:00
Subject: Re: PATCH to make internal Hash class retain order...

Brian McCallister wrote:
> 
> On Aug 12, 2006, at 9:55 AM, Thies C. Arntzen wrote:
> 
>> Hi there -
>>
>> beeing new to ruby (thru rails) and coming from a strong php  background
> 
> 
> <snip />
> 
>> * remember the order in which elements have been added to a Hash (at
>> the cost of 2 extra pointers in every hash-bucket + 2 extra pointers
>> per hash-table)
>> * use this order for iterating (st_foreach will use this order)
>> * implement a call Hash.order! allows the user to change the internal
>> order;-)
> 
> 
> Nice :-) The better place for discussion hacking on the ruby  
> interpreter itself is probably ruby-core.
> 
> How difficult would it be to do an OrderedHash data structure as a C  
> extension instead of in Ruby?

Well, if it were another class, then you would lose the order
information before you ever got into that class, right?

hash = {a=>1, b=>2, c=>3}

ordered = OrderedHash.new(hash)   # Oops -- too late


Hal