On Mon, 25 Sep 2023 16:59:30 GMT, Jan Lahoda <jlah...@openjdk.org> wrote:
>> This PR finalizes the feature of unnamed variables and patterns. >> >> --------- >> ### Progress >> - [ ] Change must be properly reviewed (1 review required, with at least 1 >> [Reviewer](https://openjdk.org/bylaws#reviewer)) >> - [x] Change must not contain extraneous whitespace >> - [x] Commit message must refer to an issue >> - [ ] Change requires CSR request >> [JDK-8315851](https://bugs.openjdk.org/browse/JDK-8315851) to be approved >> >> >> >> ### Reviewing >> <details><summary>Using <code>git</code></summary> >> >> Checkout this PR locally: \ >> `$ git fetch https://git.openjdk.org/jdk.git pull/15649/head:pull/15649` \ >> `$ git checkout pull/15649` >> >> Update a local copy of the PR: \ >> `$ git checkout pull/15649` \ >> `$ git pull https://git.openjdk.org/jdk.git pull/15649/head` >> >> </details> >> <details><summary>Using Skara CLI tools</summary> >> >> Checkout this PR locally: \ >> `$ git pr checkout 15649` >> >> View PR using the GUI difftool: \ >> `$ git pr show -t 15649` >> >> </details> >> <details><summary>Using diff file</summary> >> >> Download this PR as a diff file: \ >> <a >> href="https://git.openjdk.org/jdk/pull/15649.diff";>https://git.openjdk.org/jdk/pull/15649.diff</a> >> >> </details> >> >> >> ### Webrev >> [Link to Webrev >> Comment](https://git.openjdk.org/jdk/pull/15649#issuecomment-1733906010) > > test/langtools/tools/javac/lambda/IdentifierTest9.out line 33: > >> 31: IdentifierTest.java:152:17: compiler.err.use.of.underscore.not.allowed >> 32: IdentifierTest.java:158:16: >> compiler.err.use.of.underscore.not.allowed.with.brackets >> 33: IdentifierTest.java:160:25: compiler.err.use.of.underscore.not.allowed > > Note the errors are like: > > /home/jlahoda/src/jdk/jdk2/test/langtools/tools/javac/lambda/IdentifierTest.java:160: > error: as of release 21, the underscore keyword '_' is only allowed to > declare > for(String _s : _ ) { > ^ > unnamed patterns, local variables, exception parameters or lambda parameters > > > At least the release version should be updated, but to not let the message to > be broken into two lines like this. Maybe produce a top-level diagnostic > along the line of "underscore not allowed here" with sub-diagnostic with the > details (which then can (maybe?) span multiple lines). > > Also, the wording sounds to me like if there was a restriction in JDK 22, > while underscore is actually permitted on more places than before. > > So, maybe something like: > > > underscore not allowed here > as of release 9, ''_'' is a keyword, and may not be used as an identifier > as of release 21, ''_'' can be used as a name in the declaration of unnamed > patterns, local variables, exception parameters or lambda parameters > > ? > Just an idea. I agree. Also, this is not helped by the fact that in this particular message, the `_` does not appear in a variable declaration. Maybe we should use two distinct messages for when `_` is found as an "expression" (e.g. an identifier) and when it is used as a declaration _name_. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/15649#discussion_r1336987040
