-- main.mcl --
import "golang"
import "iter"

$fn = func($x) { # notable because concrete type is fn(t1) t2, where t1 != t2
	len($x)
}

$ins = ["a", "bb", "ccc", "dddd", "eeeee",]

$out = iter.map($ins, $fn)

$t = golang.template("out: {{ . }}", $out)

test "${t}" {}
-- OUTPUT --
Vertex: test[out: [1 2 3 4 5]]