RE: [aspectj-dev] Named advice

["Gregor Kiczales" <gregor@xxxxxxxxx>]

> What do you think of having metadata tags on advice? It seems 
> logical, and I assume it is possible to put metadata tags on 
> anonymous classes so it's analogous to something in Java. It 
> would also give a means of picking out advice elements.

I'm sure we'll support that syntactically.  But I think it would
be kludgy to then use the tags for some semantic effect in AspectJ.

> Another possible use of named advice would be defining advice 
> precedence within an aspect, rather than using ordering in 
> the file. It would also facilitate tools support (so you can 
> pick the advice to see in a browser and can see the name of 
> the advice that affects something).

We considered the above.  The former seems little to gain for a
new language feature. The latter wasn't language semantics, so
we didn't add names for it.


> I don't feel that having an optional name for advice will add 
> much complexity. I can't suggest making it mandatory because 
> of backward compatibility. I do grant you that we have to set 
> a high bar to adding features to preserve simplicity. 

No single addition adds much local complexity.  But taken together,
all the features project both a real complexity and an "apparent
heft".

Its clear that one of the common arguments against AspectJ is that
it is "too big and complex". As you know, I think that argument is
somewhat bunk.  We could and should address it by more clearly teaching
that AspectJ has a kernel, and then things like extra join points and
extra pointcuts are orthogonal.  But that argument is out there, and
we need to keep it in mind.

> For that matter, if we were willing to make incompatible 
> changes, I'd rename "after" advice to "after finally", so 
> it's more clear instead of confusing novices...

For better AND for worse, we said a long time ago it was too
late to make that change.  :)