#!/usr/bin/perl -l

# https://www.perlmonks.org/?node_id=11105885

use strict;
use warnings;
use Data::Dumper; 

my @a = 1 .. 14;

my $buckets = 4;

my @buckets;

my $place = ',';

$_ = $place x ( @a + $buckets - 1 );

my $space = $buckets - 1;

my @bucket;

/
	(?(?{ $buckets <= pos }) (*ACCEPT) )
	(?{ @bucket = (); })
	(?: .{$space} $place
		(?{ push @bucket, ( pos ) - $buckets })
		)++
	(?{ push @buckets, [ @a[ @bucket ] ] })
	(*FAIL)
	/x;

print Dumper( @buckets );