-- main.mcl -- import "fmt" class double($to_str, $x) { $name = $to_str($x + $x) test [$name,] {} } include double(func($x) {fmt.printf("%d", $x)}, 42) include double(func($x) {fmt.printf("%s", $x)}, "hello") -- OUTPUT -- Vertex: test[84] Vertex: test[hellohello]