-- main.mcl --
# this should be a function as a value, iow a lambda
$prefixer = func($x) {
	"hello" + $x	# i'd only ever expect one "hello" string in the graph
}

$out1 = $prefixer("a")
$out2 = $prefixer("b")

test "${out1}" {} # helloa
test "${out2}" {} # hellob
-- OUTPUT --
Vertex: test[helloa]
Vertex: test[hellob]