Smylers wrote:
I was wondering whether it'd be better to have this specified per
C<return> rather than per C<sub>.
I doubt it. There's no performance gain from partial caching since
you have to check the cache anyway to detect that a particular result
isn't cached.
And in those rare cases where you really do need partial caching, the
simplest solution is to split the partially cached subroutine into a
fully cached sub and an uncached sub:
sub days_in_month(Str $month, Int $year)
{
$month = lc $month;
if $month eq 'feb'
{
my sub feb_days (Int $year) is cached {
my $leap = $year % 4 == 0
&& ($year % 100 != 0 || $year % 400 == 0);
return $leap ? 29 : 28;
}
return feb_days($year);
}
else
{
# Simple look-up, so caching would be counter-productive:
return %days{$month}; # %days was declared above (honest)
}
}
Damian
