Closure conversion vs silly type parameter

[Neal Gafter]

Thanks for the report!

On Wed, May 14, 2008 at 1:18 AM, Mark Mahieu <mark at twistedbanana.demon.co.uk>
wrote:

> Thanks Neal.  I also ran into this:
>
>
> public class WrongFoundType {
>
>     static <T extends {=> void}> void foo(T block) {
>         block = { ==> };
>     }
> }
>
>
> Attempting to compile it yields an 'incompatible types' error as expected,
> but the 'found' type substituted into the error message is incorrect (should
> be '{ ==> void }' not '{ => void }'):
>
>
> WrongFoundType.java:4: incompatible types
> found   : { => void}
> required: T
>         block = { ==> };
>                   ^
> 1 error
>
>
> Regards,
>
> Mark
>
>
>
> On 14 May 2008, at 07:00, Neal Gafter wrote:
>
> Looks like a bug.  Thanks for reporting it!  I'll tell you when it's fixed.
>
> Regards,
> Neal
>
> On Tue, May 13, 2008 at 7:37 PM, Mark Mahieu <
> mark at twistedbanana.demon.co.uk> wrote:
>
>> This one has me scratching my head a bit.  The following (rather odd)
>> class compiles successfully despite there being a checked exception thrown
>> which is never caught or declared to be thrown in the method signatures:
>>
>>
>> public class Hmmm {
>>
>>    public static void main(String[] args) {
>>        foo() {
>>            throw new Exception();
>>        }
>>    }
>>
>>    static <T extends {==> void}> void foo(T block) {
>>        block.invoke();
>>    }
>> }
>>
>>
>> Interestingly, the following version, which assigns the closure literal to
>> a variable of the corresponding function type first, fails to compile (which
>> is as I'd expect).
>>
>>
>> public class Hmmm2 {
>>
>>    public static void main(String[] args) {
>>        { => void throws Exception} f = {=> throw new Exception(); };
>>        foo(f);
>>    }
>>
>>    static <T extends {==> void}> void foo(T block) {
>>        block.invoke();
>>    }
>> }
>>
>>
>> Reading the closure conversion and function type subtyping rules again, I
>> can't see why one would be allowed and the other not... any clues as to what
>> I'm missing here?
>>
>>
>> Mark
>>
>>
>
>
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