From: Robert Dober <robert.dober@...>
Date: 2008-06-27T04:45:47+09:00
Subject: Re: A cleaner way to pass a block or proc

On Thu, Jun 26, 2008 at 9:18 PM, ara.t.howard <ara.t.howard@gmail.com> wrote:
>
> On Jun 26, 2008, at 12:44 PM, Robert Dober wrote:
>
>> That is what OP wanted IIANM, the nils raise an exception later on.
>> Anyway I thought I had made it clear that your code is preferable but
>> I feel that teaching what Proc::new is about, is part of our job here
>> ;)
>
>
> ah.  btw - i did not know about the argumentless Proc::new so you achieved
> your goal ;-)
>
> a @ http://codeforpeople.com/
> --
> we can deny everything, except that we have the possibility of being better.
> simply reflect on that.
> h.h. the 14th dalai lama
>
>
>
>
>


Great I will spell it out for OP

Block::new takes implicitely the block you have passed to a method

irb(main):001:0> def a
irb(main):002:1>    Proc::new.call
irb(main):003:1> end
=> nil
irb(main):004:0> a do 42 end
=> 42


However if there was no block passed to the method there will be an error
irb(main):005:0> a
ArgumentError: tried to create Proc object without a block
	from (irb):2:in `new'
	from (irb):2:in `a'

This error was caught by my rescue clause in the line

@notifiers << ( Proc::new rescue notifier )


But please again, Ara's code is better idiomatic Ruby, but just in
case you stumble around Proc::new one day ;)

HTH
Robert
-- 
http://ruby-smalltalk.blogspot.com/

---
AALST (n.) One who changes his name to be further to the front
D.Adams; The Meaning of LIFF