DB<104> @x=1..4 => (1, 2, 3, 4) DB<105> use feature state; my @y = map { state $z = 0; $z += $_ } @x; => (1, 3, 6, 10) DB<106> my $z; my @y = map { $z += $_ } @x; => (1, 3, 6, 10)