Field and Method Literals

[Collin Fagan]

I'm not on the experts group .. probably for good reason, but has the three
forms of method references changed?

As of at least one of the prototypes you could:

Class Person{

String getName(){ ... }

static defaultName() { ... }

}

interface StringProvider{
     public String value();
}

// bound reference to the instance of tom's getName method
Person tom = new Person();
StringProvider name = tom#getName;

// assign a static method, using the class name
StringProvider name = Person#defaultName;

interface StringFromPersonProvider{
     public String value(Person p);
}

// unbound reference to an interface that takes Person as it's parameter.
// this is like Method.invoke()
StringFromPersonProvider fromPersonName = Person#getName;

The last one is the one I'm most excited about, but it also seems to be the
one I can't find in my email. I was sure someone told me unbound non-static
was on the table ...

Collin

On Sun, Apr 17, 2011 at 7:47 PM, Rémi Forax <forax at univ-mlv.fr> wrote:

> On 04/17/2011 10:04 PM, Alessio Stalla wrote:
>
>> On Sun, Apr 17, 2011 at 8:14 PM, Collin Fagan<collin.fagan at gmail.com>
>>  wrote:
>>
>>> *Adding or removing formal parameters of that method will break the
>>> compatibility.*
>>>
>>> Isn't this almost always the case? I'm having a hard time understanding
>>> why
>>> it's any worse to break an annotation then any other line of code.
>>>
>> A agree. Also, he's talking about Spring, where annotations are used
>> for the configuration of a graph of objects and are necessarily tied
>> to the implementation (intended as method signatures in this case).
>>
>
> I found a nice post from Gavin King that explains why
> depending on interceptor implementation is not a good idea:
>  http://relation.to/Bloggers/OnCDIInterceptorBindings
>
> I think you can easily apply this principle to constant method handle
> in annotations.
>
>
>  But more to the point what is Chris actually asking for? Is it just to be
>>> able to use static method references with annotations?
>>>
>> I believe he's asking for non-static method references without a
>> receiver object, usable in annotations.
>>
>> Alessio
>>
>
> Rémi
>
>