Closure field assignment generates bad code

[zeen]

Assigning a closure to a class field generates code which doesn't compile. It fails in different ways depending on whether it's assigned from outside the class, or inside, and whether the field is static or non-static.

import objc.foundation.NSDictionary;
import ios.ui.UIApplicationMain;
import ios.ui.UIApplicationDelegate;
import ios.ui.UIResponder;
import ios.ui.UIApplication;
import ios.ui.UIWindow;

class MyClass {
    public var closure :String->Void;
    public function new() {}
}

class ClosureTest extends UIResponder implements UIApplicationDelegate {

    public static function test() {
        trace("Before");
        var x = new MyClass();
        x.closure = function(s) { trace(s); };
        x.closure("Closure!");
        trace("After");
    }

    public static function main() { return new UIApplicationMain ( ClosureTest ); }
    public static function unusedMain(){}
    public var window :UIWindow;
    public function application (application:UIApplication, didFinishLaunchingWithOptions:NSDictionary) :Bool {
        test();
        return true;
    }
    public function applicationDidBecomeActive (application:UIApplication) :Void {}
    public function applicationWillResignActive (application:UIApplication) :Void {}
}