From: Mischa Fierer <f.mischa@...>
Date: 2009-02-25T23:52:14+09:00
Subject: Re: Where is splat implemented? / How does it work?

David,

Thank you for your reply.

However, what I'm wondering is, where does it "tie" itself to 
to_ary/to_a? Also, I think it is not the same thing as to_a, when used 
like so:

>> [[1,2,3].to_a]
=> [[1, 2, 3]] # outer length = 1
vs
>> [*[1,2,3]]
=> [1, 2, 3] # length = 3
>> 

Or

>> str = "asdf"
>> def str.to_a
>>   ["oops"]
>>   end
=> nil

>> [*str]
=> ["oops"]

vs

>> [str.to_a]
=> [["oops"]]

I'm really curious where / how this happens. If anyone can point me to 
either rubinius or to mri, I would be very grateful.


M


David A. Black wrote:
> Hi --
> 
> Mischa Fierer wrote:
>>
>> Short of reading eval.c, does anyone have any pointers?
> 
> It ties itself to to_a:
> 
>  >> obj = Object.new
> => #<Object:0xa43db54>
>  >> def obj.to_a; [1,2,3]; end
> => nil
>  >> a = *obj
> => [1, 2, 3]
> 
> That code works the same in 1.8 and 1.9.1. There may be some classes
> where it's optimized away so that you can't override it even by defining
> to_a. I'm not sure.
> 
> 
> David
> 
> --
> David A. Black / Ruby Power and Light, LLC
> Ruby/Rails consulting & training: http://www.rubypal.com
> Coming in 2009: The Well-Grounded Rubyist (http://manning.com/black2)
> 
> Ruby Training Atlanta! April 1-3, http://www.entp.com/training/atlanta09

-- 
Posted via http://www.ruby-forum.com/.