Serialization opt-in syntax (again)

[Remi Forax]

On 10/08/2012 06:24 PM, Kevin Bourrillion wrote:
> I'm sorry that I'd forgotten this _ suggestion before. I like it.

We talk about _ as an identifier, not as a placeholder for a type.

Brian, I suppose that you can use '_' everywhere the inference is used,
so Array.<_>asList(2, 3) is also legal ?

Rémi

>
>
>
> On Mon, Oct 8, 2012 at 9:20 AM, Brian Goetz <brian.goetz at oracle.com 
> <mailto:brian.goetz at oracle.com>> wrote:
>
>         still evaluate whether it's worth offering the (& Serializable)
>         shorthand as well.  The shorthand has benefits similar to the
>         Java 7
>         "diamond", though I must concede the situation only comes up a
>         tiny
>         fraction as often.
>
>
>     I agree that it is worth considering such.  But, my preference
>     here would be to deal with this and other sorts of verbosity in a
>     single more coordinated stroke, rather than ad-hoc shorthands.
>      For example, at the EG meeting we talked about reclaiming _ as a
>     syntactic token.  One of the motivations for having an "I don't
>     want to say" token would be to support partial type inference.
>      For example, we currently support diamond as all-or-nothing, but
>     something finer-grained could fit right into our existing
>     machinery if it had a syntax:
>
>       new Foo<String, _>(...)           // partial diamond
>
>     Similarly, we support inferring lambda type parameters as
>     all-or-nothing, but given a syntax, could do something finer-grained:
>
>       (String s, _ y) -> ...            // partial implicit lambda
>
>     And for target-typed lambdas, we could let inference fill in what
>     is known about the target type:
>
>       (_ & Serializable) e -> true
>
>     I think a more coordinated attack (in the future) on redundant
>     type declarations would be a better choice than creating ad-hoc
>     shorthands in specific situations.  (Obviously we'd have to have a
>     long discussion on the actual syntax.)
>
>
>
>
> -- 
> Kevin Bourrillion | Java Librarian | Google, Inc. |kevinb at google.com 
> <mailto:kevinb at google.com>
>