I gave a talk on Perl 6 Junctions at the Thousand Oaks Perl Mongers
meeting last night
http://www.hcoop.net/~terry/perl/talks/p6-junctions/index.html
and two questions/desires came out of it:
1: will it be possible to know which element of a junction is
currently being used? E.g.:
my @first_set = qw(1 1);
my @new_set = qw(1 1.4 1 1 8 1 1 1 0.8);
my $any_new_set = any(@new_set);
my $any_first_set = any(@first_set);
if ( (abs($any_first_set - $any_new_set)) > 0.5) {
"a variation in the readings is too large".say;
printf "we we examining %d and %d when it happened",
$any_new_set.current, $any_first_set.current ; # desired feature
}
2: Unless the array of values can be specified lazily, it will not be
practical to use Perl 6 Junctions on large datasets. For example I
might like to be able to specify a sub ref/closure whose execution yields a
new array value or undef when no more values. I.e.:
sub mynext {
my($age) = $sth->fetchrow_array;
$age
}
my $junction = any(\&mynext) ;
3: Do junctions short circuit? I.e., whenever the condition is met,
does it continue immediately. Using the example from point #1, can we assume
that the body of the "then" branch will fire when 8 of @new_set is
encountered?
