Aaron Sherman wrote:
> All of this is still coming into focus for me, and I want to spend
> more time reading the articles later, but for now I just wanted
> to see if anyone else has been thinking these thoughts....
I do like the idea of AOP; but I think the mechanism you suggest
are too clumsy. The particular weave that you are attempting is to
add before- and after- functions to a set of existing functions.
Ideally, this shold be imposed on the functions from outside.
Otherwise you are simply proposing an aternative syntax for
function calls within the sub body.
I'm thinking of a mechanism more like:
Class A;
sub foo { ... }
sub bar { ... }
Class B;
sub pre is before (A::foo, A::bar)
{
print "about to enter $(caller.name)\n";
}
sub post is after (A::foo, A::bar)
{
print "leaving $(caller.name)\n";
}
Class C;
sub another
{
...
}
&another is after (A::foo, B::pre);
A good reflection mechanism makes it easy to write code that
finds all the methods on a class, so the requirement for a
list of method names is not onerous even when you want to
apply an after- function to all the methods of a class.
There are, of course, a number of issues to consider. Is
C<caller> the correct context for the woven function? What
order do multiple before/after functions get called in?
How do they interact with inheritance? Ideally, it should
be possible to write a precondition (assertion) checker
in a base class that is inheritied when its method is
overridden in a subclass
As you said, these are still early ideas.
Dave.
--
Dave Whipp, Senior Verification Engineer,
Fast-Chip inc., 950 Kifer Rd, Sunnyvale, CA. 94086
tel: 408 523 8071; http://www.fast-chip.com
Opinions my own; statements of fact may be in error.
