Re: Proc initialize method not called under certain circumstances

On Fri, Jun 29, 2007 at 06:54:49AM +0900, MenTaLguY wrote:
> On Fri, 29 Jun 2007 06:24:48 +0900, "John Lam (CLR)" <[e-mail]> wrote:
> > So, is it correct to assume that for language constructs that create
> > built-in types like Range, Array, Hash etc that user-defined initialize
> > methods are never called?
> 
> Yes.  Generally, Class.new calls .allocate and then #initialize on the returned
> object, but there's no guarantee that either of those methods will be used if
> the object is created a different way and/or if .new is overridden for a particular
> class.

It's not just a matter of "no guarantee", it straight up does not happen much
in a similar way as what John is asking about Proc.new vs lambda vs a method
with a block argument.

>> class Class; def initialize(*args, &block) super; puts 'hello' end end
=> nil
>> Class.new
hello
>> class Foo; end
=> nil

In eval.c, the NODE_CLASS case eventually calls rb_define_class_id which
itself calls rb_class_new which in turn calls rb_class_boot which creates the
RClass struct and sets its members.

rb_class_new_instance is never called though, which is what new is mapped to
for rb_cClass.

From my understanding, that's the reason there is that behavior for class
creation. I'd assume something similar is true for Proc's. 

Really though, I think John is wondering if this is intentional and if
so why. I'm interested in the answer to that too :)

marcel
-- 
Marcel Molina Jr. <[e-mail]>