Tie::Scalar::Sticky 1.06

Tie::Scalar::Sticky is a Perl module with block assignments to scalars.

SYNOPSIS

use strict;
use Tie::Scalar::Sticky;

tie my $sticky, Tie::Scalar::Sticky;

$sticky = 42;
$sticky = ; # still 42
$sticky = undef; # still 42
$sticky = 0; # now its zero

tie my $sticky, Tie::Scalar::Sticky => qw/ foo bar /;

$sticky = 42;
$sticky = foo; # still 42
$sticky = bar; # still 42
$sticky = 0; # now its zero

Scalars tieed to this module will reject any assignments of undef or the empty string or any of the extra arugments provided to tie(). It simply removes the need for you to validate assignments, such as:

$var = $val unless grep $val eq $_, qw(not one of these);

Actually, that is the exact idea used in this module ...
So, why do this? Because i recently had to loop through a list where some items were undefined and the previously defined value should be used instead. In a nutshell:

tie my $sticky, Tie::Scalar::Sticky => 9, string;
for (3,undef,string,2,,1,9,0) {
$sticky = $_;
print $sticky, ;
}

Should print: 3 3 2 2 1 0