From: "T. Onoma" <transami@...>
Date: 2003-12-01T12:18:48+09:00
Subject: Re: Underpinnings of Method Wrapping

On Monday 01 December 2003 12:25 am, Peter wrote:
> >   wrap foo(*args)
> >     # set a here, do other stuff not affecting the super call
> >     result = psudeo_super
> >     # use a here, do other stuff not affecting the result
> >   end
> >
> > Then we don't need pre or post. I suppose if no "psuedo_super" is given
> > it would be assumed to be like a pre? I'm not sure. What do you think?
>
> First a note: I think intrinsic and extrinsic got swapped between the
> first mention of it and now. Maybe we should try to get these things
> straight to avoid unnecessary misunderstandings. A wrap was intrinsic,
> because it was an intrinsic part of the semantics of a method, and pre and
> post were extrinsic because they were really just riding along quietly.
> That sounds logical to me. By this definition I assume above you meant
> extrinsic, right?  We could also choose some other terms that are harder
> to mix up...

Sorry, source of confusion: I used 'wrap' here to mean a combined pre and 
post. (Mentally, I'm still repeating def for an intrinsic wraps). Perhaps 
better terms are: inner wrap and outer wrap? So with the above I was pointing 
out that we could just have a separate keyword for outer wrap definitions.

> Now for pseudo_super; it looks a bit weird, but I haven't got any better
> idea yet. I'm toying with something like this:
>
>   pdef foo(*args)
>     pre
>       a = something
>       # blah
>     post
>       print a
>       # blah2
>     end
>   end
>
> It's just that I want to get rid of the explicit call to super.

You're a man after my own heart! :-) I don't know if you noticed the research 
notes at the bottom of the RCR, but this is essentially one of the notations 
I was playing with and very much liked. Perfect for outer wraps. And pdef 
actually works pretty well too, once you think about it for a sec. Short and 
to the point.

> > Your right. Sorry. But I do think sime of the same basic methods apply.
> > Not sure. I guess I need some examples to really be able to consider.
>
> I think if we want to get AOP to Ruby, it won't hurt to have examples
> showing what it can do. For starters, we could search the AspectJ site for
> examples and see what they look like in Ruby. But for the main dish we
> probably need examples of our own to show the Full Potential. But I'm
> looking at a busy week now, but after that I'll have some time to give it
> a serious try.

That would be great, I have some other work to do too. So afterward, I take it 
you want to collaborate on a finalized joint RCR on the matter? That would be 
excellent. And yes, some good examples are quite important.

> > I think you're right on. My implementation, instead, just adds more of
> > the same:
>
> IMO, they both make sense. The existing version should use the
> redefinition syntax, your new version the wrapping syntax, agreed?

I think so. Could you clearify these two different syntaxes and where they 
apply, so that I can be sure that I'm understanding you correctly?

-t0