• how do we make sure that there's only one "tail" pattern? where's the latest we can fail here

I made it so that after a tail pattern, ] is expected

• do we add it as a token, or "just" eat two . tokens?

There is already a .. token

• what's case [..rest] => ...? error or the whole list?

Whole list, why not

• how do we write an ignored splat? can we just write [head, ..] or do we need [head, .._]?

Write [head, ..]

• trailing commas?

Not after a splat. (Could change this, but I think there is no argument for it, as splat is always last)

What do you mean with with val [x, y] = foo { ... }? Is it even possible/not a compile error because length of list is unknown? Maybe I could do val [x, ..y] = lst

@jiribenes

What do you mean with with val [x, y] = foo { ... }? Is it even possible/not a compile error because length of list is unknown?

Ah, sorry, you can do val-else (val [x, y] = foo { ... } else panic("ohno")) and with-val-else :)

I also rewrote manyTrailing. Should be enough pos tests for now 🙏