Thanks Tagir. Will address this in the next draft. Gavin
> On 20 Sep 2019, at 03:31, Tagir Valeev <amae...@gmail.com> wrote: > > Hello, Gavin! > > In general, the spec draft looks good. I have a question about > annotations. Currently section 9.6.4.1. @Target says: > > 9. Local variable declarations (including loop variables of for > statements and resource variables of try-with-resources statements) > (§14.4, §14.14.1, §14.14.2, §14.20.3) > Corresponds to java.lang.annotation.ElementType.LOCAL_VARIABLE > > Should not it be extended to include pattern variables as well? > > With best regards, > Tagir Valeev. > > On Thu, Sep 19, 2019 at 4:30 PM Gavin Bierman <gavin.bier...@oracle.com> > wrote: >> >> A draft language spec for JEP 305 (Pattern Matching for instanceof) is >> available at: >> >> http://cr.openjdk.java.net/~gbierman/jep305/jep305-20190918/specs/patterns-instanceof-jls.html >> >> <http://cr.openjdk.java.net/~gbierman/jep305/jep305-20190918/specs/patterns-instanceof-jls.html> >> >> Comments are welcomed on all aspects, but I draw your attention to a couple >> of things that we’d like your feedback on: >> >> 1. The instanceof operator restricts the type to be a reifiable reference >> type. The spec currently keeps that restriction for type test patterns too. >> But should we go further, i.e. will people expect to be able to say the >> following (given that this *declares* a pattern variable l)? >> >> if (o instanceof List<Integer> l) { >> … >> } >> >> 2. We’d like to keep the possibility open for merging of multiple pattern >> declarations, where it makes sense. For example: >> >> if (a instanceof Foo f || b instanceof Foo f) { >> … // Like to be able to use f here >> } >> >> The current spec explicitly calls out cases like these as compile-time >> errors, to allow for forwards compatibility if we add this feature. But what >> do you think of this feature? (We have textually multiple declarations of a >> pattern variable, but they are “merged”, so they are really the same thing…) >> >> 3. [Only for spec nerds] I am proposing to add a new Chapter 16 to discuss >> patterns (at the moment it’s short, but we’re planning for it to grow). The >> existing Chapters 16-19 will be renumbered to 17-20. Will this renumbering >> cause problems for anyone? >> >> >> Thanks, >> Gavin
