Compound extension

Language Design
20

My proposition works just as expected in your example. We match not the tail of scope sequence but the latest subsequence. Let me try to explain it again.

Consider we have a sequence like G, A1, B, C, A2. Now we have a few functions, which will be bound to this scope:

  • [A]. will be bound because we have A in the sequence. It is not the last, but it does not matter.

  • [A, B]. and [A, B, C]. will be bound for the same reason.

  • [C, A]. will be bound because we have a subsequence of C, A2.

  • [C, B]. won’t be bound because the order mismatch (if we stick to order-based approach).

  • [A, B, A]. also won’t bind because you do not have second A, you will have to explicitly say a.doSomething() for it to work.

So, as you see, all the classics work as you expect, the only confusion arises when you have some complicated cases with repeating types.