These will be supported in future versions; this is not something that I
want to rush, nor is it something I want to hold up the first GNU release;
it is likely to be a much lesser-used feature.
This is a consequence of ease.js' careful trait implementation that ensures
that any mixed in trait retains its API in the same manner that interfaces
and supertypes do.
As described in <https://savannah.gnu.org/task/index.php#comment3>.
The benefit of this approach over definition object merging is primarily
simplicitly---we're re-using much of the existing system. We may provide
more tight integration eventually for performance reasons (this is a
proof-of-concept), but this is an interesting start.
This also allows us to study and reason about traits by building off of
existing knowledge of composition; the documentation will make mention of
this to explain design considerations and issues of tight coupling
introduced by mixing in of traits.
Note the incomplete tests. These are very important, but the current state
at least demonstrates conceptually how this will work (and is even useful in
its current state, albeit dangerous and far from ready for production).
This is a rough concept showing how traits will be used at definition time
by classes (note that this does not yet address how they will be ``mixed
in'' at the time of instantiation).