ClosureClass.js

class Point(x, y) extends Something {

    move(x, y);

    public X = 0, Y = 0;

    public move(x, y) {
        X = x;
        Y = y;
        repaint();
    }

}

Point.fromString = function (s) {
    return new Point(parse(s));
}

LexicalClass.js

class Point {

    X: 0,
    Y: 0,

    static fromString: function (s) {
        return new Point(parse(s));

    },

    initialize: function (x, y) {
        move(x, y);
    },

    move: function (x, y) {
        X = x;
        Y = y;
        repaint();
    }

}