It is a most unusual way to solve this kind of selection problems by using references. You get into the dreaded Action at A Distance anti-pattern by doing so. It is much more obvious to just write a function:
my $last = 0;
my $ini = 0;
...
$last = <something else>;
...
$ini = <something else>;
... # now you need $some_value:
my $selector = 'SAS1';
my $some_value = compute_sas($selector, $ini, $last);
sub compute_sas {
my($selector, $ini, $last) = @_;
if($selector eq 'SAS1') {
return $ini - $last;
} else {
return $last - $ini;
}
}
Note that the sub compute_sas is sloppy, untested and probably not giving the right results, but it should illustrate my point.
