#!/usr/bin/perl
use strict;
use warnings;
my $item = qr /(?:[Aa]|\d+(?:-\d+)?)/;
my $list = qr /^$item(?:,$item)*$/;
while (<DATA>) {
chomp;
print "$_: ", /$list/ ? "matches\n" : "does not match\n";
}
__DATA__
1
1-3
a
1,4-6,a
1,4-6,,a
1,4-6,
,1,4-6,a
1,4-6,b
1,4-6-8,a
1,4-a,2
1,4-6,4-6,1234-12,a
1: matches
1-3: matches
a: matches
1,4-6,a: matches
1,4-6,,a: does not match
1,4-6,: does not match
,1,4-6,a: does not match
1,4-6,b: does not match
1,4-6-8,a: does not match
1,4-a,2: does not match
1,4-6,4-6,1234-12,a: matches
Abigail