gravity-lang/binding/shared/main.gravity

// to be later registered at runtime
extern var ObjC;

// list here all the ObjC classes to register and use
var Alert

func loadObjCClasses() {
    Alert = ObjC.register("NSAlert")
}

func main() {
    loadObjCClasses();
    
    // ObjC Hello World
    var alert = Alert()
    alert.messageText = "Hello World"
    alert.informativeText = "Hello from Gravity!"
    alert.runModal()
    
    return 0
}