Re: concerns about Proc,lambda,block

Hi --

On Tue, 2 Mar 2004, ts wrote:

> >>>>> "D" == David A Black <[e-mail]> writes:
> 
> D> I think Dave's explanation is about as good as one can give -- and
> D> that's what worries me.  In particular, the fact that Ruby is now
> D> doing something that requires the concept of "contexts" to explain
> D> strikes me as an indication of a possible problem.  
> 
>  Well, the problem is perhaps that he try to rationalize (he must be
>  cartesian :-)) when you must "visually" see the examples.

But there isn't any visual information to go on, once these objects
leave the site of origin.  Nor do the objects differentiate themselves
very clearly:

   irb(main):012:0> n.methods - m.methods
   => []
   irb(main):013:0> n.class == m.class
   => true
   irb(main):014:0> n.arity == m.arity
   => true
   irb(main):015:0> n.call
   ArgumentError: wrong number of arguments (0 for 2)
	   from (irb):15:in `x'
	   from (irb):8:in `call'
	   from (irb):15
   irb(main):016:0> m.call
   => nil
   irb(main):017:0> RUBY_VERSION
   => "1.9.0"

There's nothing wrong with having code blocks/closures that behave
differently.  But it isn't represented in the language the way that
other such differences between built-ins are.  (And the actual rules
having to do with arity also seem very complex to me.)


David

-- 
David A. Black
[e-mail]