[Grace-core] Abstract methods/classes

[James Noble]

>> I'm leaning back to the annotation approach, where it just bans you from calling
>> it directly, but allows you to call it through super or inherit from it. That
>> way it works for both methods and class methods.
> I don't know what this means either.

??

> The advantage of abstract in the body is that it works within the
> existing semantics of the language, rather than being a special case.

right

> I suspect the claimed advantage of an annotation is that it works
> outside the existing semantics of the language and is a special case,
> however, so take your pick of those.

right. also it's similar to many other annotation-like things in Grace

James