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();

[download]

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

[download]

Dave

In reply to Re: split versus =~ by davido
in thread split versus =~ by russlo

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