Well, the problem in my opinion is, that a square is a rectangle, indeed. However, this is not square is-a rectangle;, but rather: square is-a rectangle with re

Well, the problem in my opinion is, that a square is a rectangle, indeed. However, this is not square is-a rectangle;, but rather: square is-a rectangle with rectangle.height == rectangle.width; This is overall something I have been pondering (and recently planning and implementing) to extend the standard object orientation: adjectives (opposed to 'nouns' (objects) and 'verbs' (methods)). An adjective would simply describe a noun furhter and simplify a dispatch inside a method depending on the state of an object. Some pseudosyntax from the current state of ideas would go like this: adjective_group rectangle_type(R) { if(R.width == R.height) { return square; } else if(R.width * 4 = R.height * 3) { return widescreen; } } draw(square rectangle R) { // specialized draw for squares } draw(widescreen rectangle R) { // specialized draw for widescreen rectangles } draw(rectangle R) { // general drawing method for rectangles } This goes pretty deep if one starts to think about it: * Buffers: empty, full, something in between * Abstract syntax trees: well-typed, ill-typed * Accounts: banned, active, moderator, admin Basically, it simplifies the pattern method(object) { if (predicate_1(object.state)) { // stuff } else if(predicate_2(object.state)) { // other stuff } else { // default stuff } } I am just currently working on a dispatch mechanism which is at least a bit intuitive :)