From: Peter <Peter.Vanbroekhoven@...>
Date: 2003-12-10T22:47:13+09:00
Subject: Re: Underpinnings of Method Wrapping

> Sorry, Peter. I just noticed that I may have misread this. You still mean to
> use wraps just not cflow. Is that what you mean? I thought by *explict* you
> meant not using wraps at all.
>
> I can see that cflow may not be easier as compared to just keeping a varaible
> status, although they are practically interchangable -- once you determine
> the algorthim that relates the cflow to such a variable. But if cflow causes
> too much interpretor overhead to maintain, then variable is quite reasonable.

Yep, that's the point. Writing it using cflow is a different way of
thinking - which isn't necessarily bad - but it may not match the fact
that the code you're looking at is procedural. There is a reason why
program analyses - which look at the program in a mathematical way - are
limited in their possibilities. It is even hard to do it oneself in the
general case. And I used the term explicit probably because cflow is what
AspectJ offers and it implements it using a wrap and a avriable, so the
former is a higher level description of the latter which is then explicit.
They can do that in AspectJ by limiting the combinations of cflow (&&, ||,
!), and because it's a static language. Also they don't have to deal with
method redefinition. As such, I'm sure they can handle more complex
expressions involving cflow and have little overhead at runtime.

Peter