> > You can't predict when the last time a module is going to get used...
>
> I'm not suggesting you need to. I'm saying that, just as all
> UNITCHECKs are
> guaranteed to run before any main CHECK, we might want a UNITEND that's
> guaranteed to execute before any main END.
Perhaps this is one of those places where properties can help. Instead of
having BEFORE, REALLY_BEFORE, NO_I_MEAN_REALLY_BEFORE, DONE, MOSTLY_DONE,
PARTIALLY_DONE, WELL_DONE, DONE_AND_PROCESS_SPACE_ALMOST_RECLAIMED, etc., we
could simply use some ordering properties:
# Each "broad class" of upcased block is an execution group. The entries
# in each execution group are not guaranteed to run in any particular order,
# and in fact may run in parallel on a multithreaded perl.
#
# However, blocks in the same source file are guaranteed to run in order of
# occurrence. (Since they're catenated, basically.)
#
# Thus, all "BEGIN" blocks in a file are effectively catenated and added to
# an overall "BEGIN" execution group. All the separate BEGIN entries have
# the same initial priority(10), so they will run in whatever order suits
# the P6 runtime.
#
# The C<go> property introduces changes to the execution group and/or
# priority of the block in question. (Note that different priorities may
# be attached to different blocks within the same file. Doing so creates
# separate execution bundles, and breaks any guarantees about order of
# execution.)
#
package OtherPackage;
BEGIN will go <first> {
print "first!";
}
package SomePackage;
BEGIN will go <after OtherPackage::BEGIN> {
print "Second!";
}
END will go <priority 5> {
print "End block with early priority";
}
package ThirdPackage;
END will go <group BEGIN before SomePackage::BEGIN> {
print "I feel really out of place!";
}
Comment?
=Austin
