[m-dev.] skipped predicates

[Zoltan Somogyi]

> Still, both methods does not have exactly the same behavior; with my
> method, a skipped procedure do not generate any event, even if it is
> calling a deep level procedure (I don't know which method is better in
> this respect).

Predicates that you are confident are correct may nevertheless call other
predicates in whose correctness you are not confident. This is quite likely
for higher order predicates such as list__map. If the procedure passed as
the higher-order argument to list__map was compiled with --trace deep,
the programmer may be interested debugging it, therefore it should generate
events. If the programmer does not want to see these events, he/she can use
a debugger command that skips over them.

> Another difference is that with my method, you don't need to recompile
> the modules you want to "shallowly" trace (like the library modules for
> example). 

Yes. However, you do need to know, when you are calling a procedure from
abother module, what options that other module was compiled with. In a system
with separate compilation, this info may not be available. What if the other
module gets recompiled with different options?

Zoltan.