From: Ross Bamford <rosco@...>
Date: 2005-12-02T17:42:34+09:00
Subject: Re: require!

On Fri, 02 Dec 2005 06:13:38 -0000, Hal Fulton <hal9000@hypermetrics.com>  
wrote:

> James Edward Gray II wrote:
>> On Nov 30, 2005, at 7:52 PM, Ross Bamford wrote:
>>
>>> On another note, though, I also found out that calling amethod (*args)  
>>> works with anything with 'each' (any Enumerable?), which  made me  
>>> smile. It was the post about ranges that made me get that :)
>>   Actually * looks for a to_a.
>
> I always thought it looked for to_ary... now someone says it looks
> first for to_ary, then to_a.
>
> And I had no idea that it would work with just #each defined.
>

When I kicked this thread off, I'd just done some quick tests that  
suggested it worked like above, and on anything with each, and I guessed  
that (since Enumerable defines to_a, and everything is in terms of each)  
that it must work that way.
I'm still pretty sure it does to_ary followed by to_a, but as others  
showed me, it doesn't actually work with just 'each'.

   class Clazz
     def each
       yield 1
       yield 2
       yield 3
     end
   end

   c = Clazz.new
   c = [*c]
   p c	           => [#<Clazz:0xb7f7ccdc>]

That's I think coming from the default to_a, and with the 1.9 snapshot I  
have it gives a TypeError ('Cannot convert Clazz into Array' - the default  
to_a is gone). It does _seem_ to work on anything with each if you include  
Enumerable, but that's because Enumerable defines everything (including  
to_a) in terms of 'each'. If you add 'include Enumerable' to the class  
definition above, you get [1,2,3] as expected.

-- 
Ross Bamford - rosco@roscopeco.remove.co.uk
"\e[1;31mL"