Set a font for a UITextView if the font is nil or not equal to desired font
There's a much easier way of doing this.

if self.view.font?.fontName != mongolFontName {
    view.font = UIFont(name: mongolFontName, size: defaultFontSize)
}


We should always prefer optional binding and optional unwrapping (?) to forced (!).

When the value we're optionally unwrapping is nil, we just get nil back.  And of course, nil and mongolFontName aren't going to be the same (unless you've set up mongolFontName as nil), so we enter the if's body.

Consider this example from the playground: