I am pretty sure I saw some spec language for this go by, but Gavin can
fill in the details. But yes, this is desirable because it should be
possible to mix enums and records under a sealed type:
sealed interface X { }
enum E implements X { A; }
record R(int x) implements X { }
...
switch (x) {
case E.A: ...
case R(int x): ...
// exhaustive!
}
There is some spec trickiness because switches on enum selectors _must_
use unqualified names historically, and this has to be rationalized.
On 9/26/2023 8:32 AM, Tagir Valeev wrote:
Hello! As we are finalizing this feature, can we squeeze in a little
improvement? Namely, support enum and patterns within the same case
label, provided that the patterns do not declare any variables. Like:
enum X {A, B}
static void test(Object obj) {
switch (obj) {
case String _, X.B -> System.out.println("B or String");
default -> System.out.println("other");
}
}
public static void main(String[] args) {
Test.test("ddd");
Test.test(X.B);
}
Currently, such a code is not supported. Or will it be considered in
future JEPs?
With best regards,
Tagir Valeev.
On Mon, Sep 25, 2023 at 6:25 PM Mark Reinhold<[email protected]> wrote:
https://openjdk.org/jeps/456
Summary: Enhance the Java language with unnamed variables, which
can be initialized but not used, and unnamed patterns, which match a
record component without stating the component's name or type. Both are
denoted by an underscore character, _.
- Mark
