From: "David A. Black" <dblack@...>
Date: 2005-05-22T20:19:21+09:00
Subject: Re: join not in Enumerable

Hi --

On Sun, 22 May 2005, Kristof Bastiaensen wrote:

> On Sun, 22 May 2005 11:05:10 +0900, David A. Black wrote:
>
>>> Why is join, and perhaps even pack in Array and not in Enumerable?
>>
>> I guess to_a makes the conversion pretty easy, and Array tends to
>> serve as the "normalized" version of Enumerable in a lot of contexts.
>> I don't know if there's any other reason.
>
> I believe because join requires an ordered collection, and enumerables
> aren't guaranteed to be ordered.  For example the order of traversing a
> Hash may differ for a different hash with the same elements.  For this
> reason the output of join for an enumerable is undefined.

I don't think the unorderedness would matter; consider, for example,
Hash#to_s.


David

-- 
David A. Black
dblack@wobblini.net