What I really like is writing generic min/max routines that handle more than two variables. They show the beauty of recursive functions, even though Perl doesn't handle tail-recursion
1.
Iterative:
sub max {
my ($max, @vars) = @_;
for (@vars) {
$max = $_ if $_ > $max;
}
return $max;
}
Recursive:
sub max {
my ($max, $next, @vars) = @_;
return $max if not $next;
return max( $max > $next ? $max : $next, @vars );
}
Interestingly enough, though this example works well in several languages, Perl's iterative version is remarkably short; I've never noticed this before. I guess I just proved myself wrong.
1Okay, so this isn't strictly true. Using a magic goto with the
& sigil and
@_, you can fake it. But it's not very pretty.
Update: Fixed my mistake. Thanks, pg. (I always want to use postmodifier if and for in the same statement.)
Update: Okay, so I should test my code before I post. Or find where I left my brain. Snippet 2 is fixed.
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