A couple of Bugs

[Ali Ebrahimi]

Hi Maurizio,
for this:
Array.array();
I think, since this invocation does not have receiver object(static method
call) then in method resolution phase non-static methods shoud be excluded
from consideration. In this case both JDK 6/JDK 7 fails.
now since compiler does not exclude non-static methods then it fails. But if
I commented (excluded ) non-static method, compiler can
resolve this invocation to static form, the thing that compiler can do
itself for above invocation. the compiler even does not examine static
method.

Best Regards
Ali Ebrahimi


On Tue, Jun 7, 2011 at 1:28 PM, Maurizio Cimadamore <
maurizio.cimadamore at oracle.com> wrote:

>  On 07/06/11 10:17, Ali Ebrahimi wrote:
>
> Hi Maurizio,
> No, I don't think so.
> java 6 compiler correctly resolve this invocation to static varargs method.
>
> In this case we have two array method in Test class, on static ( and
> generic) with single varargs parameter that returns Array<A> and
> other member method without any params that returns A[]. and compiler
> incorrectly try to resolve two later once.
>
> One method is static and generic, the other method is
> non-static/non-generic. Since the invocation contains the explicit
> type-arguments, JDK 6 compiler only sees the static/generic method - on the
> other hand, JDK 7 doesn't have this restriction and sees both methods as
> potentially applicable.
>
> Try this:
>
> class Array<X> {
>
>         public static <A> Array<A> array(final A... a) {
>             return null;
>         }
>
>         public X[] array() {
>             return null;
>         }
> }
>
> class Test {
>
> static void test() {
>    Array.<String>array(); //ok with JDK 6, fails with JDK 7
>    Array.array(); //static error here in both JDK 6/JDK 7
> }
>
> }
>
>
> Maurizio
>
>
>          public static <A> Array<A> array(final A... a) {
>             return new Array<A>(a);
>         }
>
>         public A[] array() {
>             return null;
>         }
>
>     public static <A> Array<A> test() {
>
>         return Array.<A>array();
>
>     }
>
> I think this clears Issue.
>
>
> Best Regards
> Ali Ebrahimi
>
>
> On Tue, Jun 7, 2011 at 12:14 PM, Maurizio Cimadamore <
> maurizio.cimadamore at oracle.com> wrote:
>
>> Hi Ali,
>> the static error you are seeing is a result of the fix for 5081782 (type
>> arguments to non-generic methods) - if you remove the explicit type-argument
>> from the following invocation:
>>
>>
>> public static <A> Array<A> test() {
>>        return Array.<A>array();
>>    }
>>
>>  You get the very same error in JDK 6. Thus, the new error in JDK 7 is
>> caused by the fact that the method Array.array() is not excluded anymore
>> from overload resolution because of explicit type-arguments.
>>
>> The other is a problem with overload resolution and nested lambda
>> expression, and will be fixed.
>>
>> Maurizio
>>
>>
>>
>> On 07/06/11 04:53, Ali Ebrahimi wrote:
>>
>>> class Test {
>>>
>>>     static class Array<A>  {
>>>         private A[] data;
>>>
>>>         Array(A[] data) {
>>>             this.data = data;
>>>         }
>>>
>>>         public static<A>  Array<A>  array(final A... a) {
>>>             return new Array<A>(a);
>>>         }
>>>
>>>         public A[] array() {
>>>             return null;
>>>         }
>>>
>>>          public boolean forAll(final F<A, Boolean>  f) {
>>>             for (final A x : data)
>>>                 if (f.f(x))
>>>                     return true;
>>>
>>>             return false;
>>>         }
>>>
>>>     }
>>>
>>>     public interface F<A, B>  {
>>>         B f(A a);
>>>     }
>>>
>>>     public static<A>  Array<A>  test() {
>>>         return Array.<A>array();
>>>     }
>>>
>>>     public static Array<Character>  fromString(final String s) {
>>>         List<Character>  cs = Collections.emptyList();
>>>
>>>         for (int i = s.length() - 1; i>= 0; i--)
>>>             cs.add(s.charAt(i));
>>>
>>>         return new Array<Character>(cs.toArray(new Character[0]));
>>>     }
>>>
>>>     public static void main(String[] args) {
>>>
>>>         final Array<String>  a = Array.array("Hello", "There", "what",
>>> "DAY",
>>> "iS", "iT");
>>>         final boolean b = a.forAll(#{String s ->  fromString(s).forAll(#{
>>> Character c ->   isLowerCase(c)}) }); //***********
>>>         System.out.println(b); // true ("what" provides the only example;
>>> try removing it)
>>>     }
>>> }
>>>
>>
>>
>
>