I can't think of a case where positive lookbehind to detect a digit preceding the hyphen wouldn't work:
#!/usr/bin/env perl
use strict;
use warnings;
use Test::More;
my @tests = (
[ '1-2-3-4' => [1,2,3,4] ],
[ '1--2-3-4' => [1,-2,3,4] ],
[ '-1-2-3-4' => [-1,2,3,4] ],
[ '1-2-3--4' => [1,2,3,-4] ],
[ '-1--2--3--4' => [-1,-2,-3,-4] ],
[ '15--20-25--30' => [15,-20,25,-30] ],
);
foreach my $test (@tests) {
my ($raw, $want) = @$test;
my @got = split /(?<=\d)-/, $raw;
local $" = ', ';
is_deeply \@got, $want, "'$raw' => [@$want]";
}
done_testing();
This produces:
ok 1 - '1-2-3-4' => [1, 2, 3, 4]
ok 2 - '1--2-3-4' => [1, -2, 3, 4]
ok 3 - '-1-2-3-4' => [-1, 2, 3, 4]
ok 4 - '1-2-3--4' => [1, 2, 3, -4]
ok 5 - '-1--2--3--4' => [-1, -2, -3, -4]
ok 6 - '15--20-25--30' => [15, -20, 25, -30]
1..6