Ruby has a public/private divide which can easily be circumvented. But the circumvention is a bit ugly, which is a good thing - it makes the circumvention obvious in the code.
Personally, I think Ruby hits a sweet spot here: the privacy curtain is strong enough that Ruby WILL let you know when you've stepped off the path of using methods which are part of the stable API. But you can then tell Ruby "yes, I understand, and I know what I'm doing".
Personally, I think Ruby hits a sweet spot here: the privacy curtain is strong enough that Ruby WILL let you know when you've stepped off the path of using methods which are part of the stable API. But you can then tell Ruby "yes, I understand, and I know what I'm doing".