On Wed, 30 Jun 2021 10:23:32 GMT, Jan Lahoda <[email protected]> wrote:
>> Currently, an enum switch with patterns is desugared in a very non-standard,
>> and potentially slow, way. It would be better to use the standard
>> `typeSwitch` bootstrap to classify the enum constants. The bootstrap needs
>> to accept enum constants as labels in order to allow this. A complication is
>> that if an enum constant is missing, that is not an incompatible change for
>> the switch, and the switch should simply work as if the case for the missing
>> constant didn't exist. So, the proposed solution is to have a new bootstrap
>> `enumSwitch` that accepts `String`s in place of the enum constants, and will
>> internally convert them to the appropriate enum constants, and then it will
>> find the proper case similarly to `typeSwitch`.
>>
>> How does this look?
>
> Jan Lahoda has updated the pull request with a new target base due to a merge
> or a rebase. The pull request now contains ten commits:
>
> - Reflecting review comments.
> - Merge branch 'master' into JDK-8268766
> - Improving javadoc.
> - Updating javadoc, as suggested.
> - Updating javadoc, code and tests as suggested.
> - Creating a new bootstrap method for (pattern matching) enum switches, as
> suggested.
> - Adding and fixing test.
> - Merging master.
> - 8268766: Desugaring of pattern matching enum switch should be improved
Looks good - added minor cosmetic comments
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java line 205:
> 203: *
> 204: * @param lookup Represents a lookup context with the accessibility
> 205: * privileges of the caller. When used with {@code
> invokedynamic},
Suggestion:
* privileges of the caller. When used with {@code
invokedynamic},
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java line 216:
> 214: * @throws NullPointerException if any argument is {@code null}
> 215: * @throws IllegalArgumentException if any element in the labels
> array is null, if the
> 216: * invocation type is not a method type of first parameter of an
> enum type,
Suggestion:
* invocation type is not a method type whose first parameter type is an
enum type,
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java line 217:
> 215: * @throws IllegalArgumentException if any element in the labels
> array is null, if the
> 216: * invocation type is not a method type of first parameter of an
> enum type,
> 217: * second parameter of type {@code int} and with {@code int} as its
> return type,
Suggestion:
* second parameter of type {@code int} and whose return type is {@code
int},
-------------
Marked as reviewed by mcimadamore (Reviewer).
PR: https://git.openjdk.java.net/jdk17/pull/81
