// setup
var bml = bulletml.buildXML("<bulletml>...</bulletml>");
var runner = bml.createRunner({
  target: playerShip, // enemy's attack target (has 'x' and 'y' property)
  createNewBullet: function(bulletRunner) { // function to be called when new bullet has been fired
    var bullet = new Bullet();
    bullet.update = function() {
      bulletRunner.update();
    };
    scene.addChild(bullet);
  }
});
runner.x = enemy.x;
runner.y = enemy.y;

enemy.update = function() {
  // every frame
  runner.x = this.x;
  runner.y = this.y;
  runner.update();
};

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE bulletml SYSTEM "http://www.asahi-net.or.jp/~cs8k-cyu/bulletml/bulletml.dtd">
<bulletml xmlns="http://www.asahi-net.or.jp/~cs8k-cyu/bulletml">
    <action label="top">
        <repeat>
            <times>10</times>
            <action>
                <fire>
                    <direction type="absolute">60</direction>
                    <bullet />
                </fire>
                <wait>5</wait>
            </action>
        </repeat>
    </action>
</bulletml>

var spec = new bulletml.Root({
    top: action([
        repeat(10, [
            fire(direction(60, "absolute"), bullet),
            wait(5),
        ]),
    ]),
});