From: "David A. Black" <dblack@...>
Date: 2009-07-06T00:08:31+09:00
Subject: Re: to_proc and Proc/block conversion with &

Hi --

On Sun, 5 Jul 2009, Bertram Scharpf wrote:

> Hi,
>
> Am Sonntag, 05. Jul 2009, 19:51:28 +0900 schrieb David A. Black:
>> On Sun, 5 Jul 2009, Joel VanderWerf wrote:
>>> Russ McBride wrote:
>>>
>>> constructing a Proc using &:
>>>
>>>  def map(&b)
>>>    b.call ...
>>>  end
>>>
>>> or equivalently with Proc.new:
>>>
>>>  def map
>>>    b = Proc.new
>>>    b.call
>>>  end
>>
>> That's not going to access the caller's code, though, since you're
>> creating a totally new Proc.
>
> Sorry, but these are not the same:
>
>  Proc.new
>  Proc.new { }
>
> Try this:
>
>  def f ; Proc.new ; end
>  p = f { "hello" }
>  p.call
>    #=> "hello"

How odd. I wonder what the point of that is. I'd rather be warned if I
write Proc.new without a block, than have it default to the code
block.

But you're right that I'm wrong in correcting Joel. Rewind.


David

-- 
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