Integrated: 8282274: Compiler implementation for Pattern Matching for switch (Third Preview)

[Jan Lahoda]

On Mon, 11 Apr 2022 16:37:03 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

> This is a (preliminary) patch for javac implementation for the third preview of pattern matching for switch (type patterns in switches).
> 
> Draft JLS:
> http://cr.openjdk.java.net/~gbierman/PatternSwitchPlusRecordPatterns/PatternSwitchPlusRecordPatterns-20220407/specs/patterns-switch-jls.html
> 
> The changes are:
> -there are no guarded patterns anymore, guards are not bound to the CaseElement (JLS 15.28)
> -a new contextual keyword `when` is used to add a guard, instead of `&&`
> -`null` selector value is handled on switch level (if a switch has `case null`, it is used, otherwise a NPE is thrown), rather than on pattern matching level.
> -total patterns are allowed in `instanceof`
> -`java.lang.MatchException` is added for the case where a switch is exhaustive (due to sealed types) at compile-time, but not at runtime.
> 
> Feedback is welcome!
> 
> Thanks!

This pull request has now been integrated.

Changeset: 0155e4b7
Author:    Jan Lahoda <jlahoda at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/0155e4b76bb0889e516811647aede500a7812db1
Stats:     1093 lines in 56 files changed: 549 ins; 320 del; 224 mod

8282274: Compiler implementation for Pattern Matching for switch (Third Preview)

Co-authored-by: Brian Goetz <briangoetz at openjdk.org>
Co-authored-by: Jan Lahoda <jlahoda at openjdk.org>
Reviewed-by: mcimadamore, vromero, abimpoudis

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PR: https://git.openjdk.java.net/jdk/pull/8182