@JavaType "org.simantics.scl.runtime.tuple.Tuple3"
data Tuple3 a b c =
    @FieldNames [c0, c1, c2] 
    Tuple3 a b c
    
toTuple (Tuple3 x y z) = (x, y, z)

main = toTuple (Tuple3 "x" "y" "z")
--
(x,y,z)