use feature qw(say state);

my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
	my @partitions = map { state $c = 0; [$c, $c += $_] } @widths;

	say '[', join(', ', @$_), ']' for @partitions;
	print "\n";
}

##</code><code>##

use feature qw(say);

my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
	my @partitions = do { my $c = 0; map { $c += $_; [$c - $_, $c] } @widths};

	say '[', join(', ', @$_), ']' for @partitions;
	print "\n";
}

##</code><code>##

use feature qw(say);

my @widths = (2, 6, 5, 7);
foreach (1 .. 2) {
	my @partitions = do { my $c = 0; map { my $old = $c; [$old, $c+=$_] } @widths};

	say '[', join(', ', @$_), ']' for @partitions;
	print "\n";
}