[Grace-core] Multiple inheritance & module inheritance

[Timothy Jones]

On 16/03, Kim Bruce wrote:
> So suppose we were to ban family polymorphism.  Is there still an issue?

You lose the simple sugar of classes as defs. Classes become something special
that cannot be overridden.

This is one of the problems that the 'let' proposal was solving: unify type
declarations and class declarations under a single kind of declaration, and ban
overriding of that.

-- 
Tim