module AvanziniOriginal;

// Higher order not supported, only partially defined functions:
// seehttp://docs.abs-models.org/#sec:partially-defined-functions

// let comp f g = fun z -> f (g z);;
def List<A> comp<A>(f, g)(A z) = f(g(z));


def List<A> walk(List<A> xs) =
    case xs {
    Nil => Nil;
    Cons(x,ys) =>
    comp(walk(ys), (List<A> z) => Cons(x, z));
};

// | Nil()-> (fun z -> z)
// | Cons(x,ys) -> comp (walk ys) (fun z -> Cons(x,z));;

def List<A> reverse(List<A> xs) = walk(xs,Nil);

def List<A> main(List<A> xs) = reverse(xs);


{ // Main

}