-- main.mcl --
import "fmt"

$map0 = {0 => "a", 1 => "b", 2 => "c",}
$map1 = {0 => "d", 1 => "e", 2 => "f",}
$map2 = {0 => "g", 1 => "h", 2 => "i",}
$map3 = {0 => "j", 1 => "k", 2 => "l",}

$list = [$map0, $map1, $map2, $map3,]

for $index, $value in $list {
	forkv $key, $val in $value {

		$s = fmt.printf("%s is %d", $val, $key+$index)
		test [$s,] {}
	}
}

-- OUTPUT --
Vertex: test[a is 0]
Vertex: test[b is 1]
Vertex: test[c is 2]
Vertex: test[d is 1]
Vertex: test[e is 2]
Vertex: test[f is 3]
Vertex: test[g is 2]
Vertex: test[h is 3]
Vertex: test[i is 4]
Vertex: test[j is 3]
Vertex: test[k is 4]
Vertex: test[l is 5]