[JEP 420] Spec Change for switch exhaustive with sealed

[Manoj Palat]

Hi Gavin, all,

For the issue “Switch coverage with multiple branches” raised in https://mail.openjdk.java.net/pipermail/amber-spec-experts/2021-July/003049.html by Dan [yeah – I know it’s a little late to ask this, but still :( ], I couldn’t figure out a spec change in JEP 420  - from the relevant part, it says the following:

“T supports a sealed class or interface named C, and the switch block is exhaustive for all the permitted direct subclasses and subinterfaces of C that are applicable at type T.”

And it still says “exhaustive for all the permitted…” However, I see that JDK18 accepts the code mentioned in the mail [via JDK-8274363 /b18].

Is there a spec change expected in the next version where this would be made explicit or is this “exhaustiveness wrt permitted classes” assumed to be an implementation detail?

Regards,
Manoj