Closure conversion vs silly type parameter

[Mark Mahieu]

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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