Note that this:
On 8/25/2020 7:53 PM, Brian Goetz wrote:
`default <deconstruction pattern>` means the same thing as `case
<deconstruction pattern>`
but it is a static error if the <deconstruction pattern> is
not_weakly_ total on the type of the selector
when combined with
I’ll add that in the last case, it is as if there is an implicit `case null:
throw`.
comports nicely with the planned semantics for pattern assignment:
P = e
requires that P be (weakly) total on the static type of e, and is
permitted to NPE when e is null. When P is a total type pattern or an
any pattern, this degenerates to normal variable declaration +
initialization. So:
Box<String> b = ...
String s = b // type error
Box bb = b // fine, total
Box(Object o) bb = b // fine, weakly total, throws NPE when b = null
I will consolidate all of this today into a new message.
