From: "David A. Black" <dblack@...>
Date: 2009-01-12T21:26:30+09:00
Subject: Re: sort hash, hash key and val off by one, see attached

Hi --

On Mon, 12 Jan 2009, Dave Bass wrote:

> Mmcolli00 Mom wrote:
>> I just need to somehow find the next key in a hash
>
> I haven't read your example, but this statement rings alarm bells. You
> need to define what you mean by "the next key". A hash has no natural
> ordering -- it's just a bunch of key-value pairs -- so it's not obvious
> what the "next" key means. The order in which you insert pairs is not
> necessarily the order in which you get them back, and this order may
> vary from one run to the next. This is basic to hashes.

It's changing in 1.9, though. 1.9 hashes are ordered by key insertion
order.

$ ruby -ve 'p({1=>"hi", "a"=>"bye", []=>"whatever"})'
ruby 1.8.6 (2008-08-11 patchlevel 287) [i686-darwin9.5.0]
{[]=>"whatever", "a"=>"bye", 1=>"hi"}

$ ruby19 -ve 'p({1=>"hi", "a"=>"bye", []=>"whatever"})'
ruby 1.9.1 (2008-12-30 patchlevel-0 revision 21203) [i386-darwin9.5.0]
{1=>"hi", "a"=>"bye", []=>"whatever"}


David

-- 
David A. Black / Ruby Power and Light, LLC
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