java 17: anonymous classes with diamonds

[Anna Kozlova]

Thanks!

On Tue, Jan 19, 2021 at 9:21 AM Srikanth <srikanth.adayapalam at oracle.com>
wrote:

>
>
> On 18/01/21 7:26 pm, Anna Kozlova wrote:
>
> Thanks!
>
> Not sure if it's exactly the same issue, could you please check as well?
> At least the error message is not very helpful: "cannot find symbol
>   symbol:   class <captured wildcard>
>   location: class foo.Boo<T>" (no line number)
>
>
> Thanks for the report, I have raised JDK-8259960 to investigate this.
>
> Srikanth
>
>
> ```
>
> import java.util.List;import java.util.function.Predicate;
> public class Boo<T> {
>     public Boo(List<? extends T> l) {
>     }
>     void m(List<? extends String> list){
>         Boo<String> boo3 = new Boo<>(findAll(list, s -> s.length() > 0)){};
>     }
>
>     static <T> List<T> findAll(List<? extends T> collection,
>                                Predicate<? super T> condition) {
>         return null;
>     }
> }
>
> ```
>
> If I remove anonymous class braces, the code starts to compile. Checked
> with with java 11 & java 17
>
> Thanks,
> Anna
>
> P.S. I've migrated IntelliJ sources to java 11 diamonds, thus the issues.
> This one is the last issue I could reproduce with java 17. A lot of issues
> have been fixed since java 11!
>
> On Mon, Jan 18, 2021 at 11:18 AM Srikanth <srikanth.adayapalam at oracle.com>
> wrote:
>
>> Thanks for the problem report Anna.
>>
>> It does look suspect and I have raised JDK-8259910 to follow up.
>>
>> This problem dates back to jdk9 and is reproducible in all the major
>> releases from then on.
>>
>> Srikanth
>>
>> On 18/01/21 3:08 pm, Anna Kozlova wrote:
>>
>> Hi all,
>>
>> The following code doesn't compile with java 17 eap (java: foo.Boo.Nested
>> is abstract; cannot be instantiated)
>> ```
>> public class Boo {
>>
>>     static abstract class Nested<T> {
>>         protected Nested(Class<T> aAcceptedClass) { }
>>
>>     }
>>     static class Outer<T>  {
>>         protected Outer(final Nested<T> condition) { }
>>     }
>>
>>     static final Outer<Boo> PATTERN = new Outer<>(new Nested<>(Boo.class) {}) {};
>> }
>>
>> ```
>> though the anonymous class is used.
>>
>> At the same time, if I remove the anonymous class from outer call, like
>> `static final Outer<Boo> PATTERN = new Outer<>(new Nested<>(Boo.class)
>> {});` the code would compile.
>>
>> If explicit types instead of diamonds are used, everything compiles fine
>> as well.
>>
>> To me this looks like a bug in the compiler, could someone check this
>> please?
>>
>> Thanks,
>> Anna
>>
>>
>>
>
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