Here the promised code for both approaches, using named captures.

NB: Using the same precompiled regexes each time.

use v5.12;
use warnings;
use Data::Dump;

my $re_start = qr{(?<start>\w+)\s*};

my $re_repeat = qr{\s*(?<repeat>\d+)\s*};

my $str = 'a 1 2 3 b 4 5 6';

while ( $str =~ /\G$re_start/g ) {
      print "$+{start}: "; 
      while ( $str =~ /\G$re_repeat/gc ) {
            print "$+{repeat} ";
      }
      print "\n";
}


my @res;
$str =~ /
            (?:
                $re_start
                (?{ push @res, $+{start} })

                (?:
                    $re_repeat
                    (?{ push @res, $+{repeat} })
                )*
            )*
        /gx;

dd \@res;

[download]

a: 1 2 3 
b: 4 5 6 
["a", 1, 2, 3, "b", 4, 5, 6]

[download]

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery

edit

In reply to Re^2: How do I reference repeated capture groups? by LanX
in thread How do I reference repeated capture groups? by TIOOWTDI

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