I see two questions: - the grammar allows to mix var and non-var for a given reference type, i think that should only permitted if the non var is a deconstruction itself ?
More generally, any pattern can appear nested inside a deconstruction pattern -- another deconstruction pattern, a var (any) pattern, a type pattern, a constant pattern ... we may not have them all right now, but any pattern will do.
- must the identifier of a pattern argument be the same name as the corresponding record component ? To be coherent with the fact that constructors requires the same names.
Nope! This is the use site; the client can name their locals however they like. Invocation of deconstructors, like constructors, is positional.
