Serialization opt-in syntax (again)

[Andrey Breslav]

Looks like we could use * instead of _ and break no programs at all (as opposed to breaking very-very few).
Nobody but hard-core functional programmers prefer one over another. 
I even suspect that * meaning "anything" in the shell when dealing with files is more familiar.

On Oct 8, 2012, at 20:24 , Kevin Bourrillion wrote:

> I'm sorry that I'd forgotten this _ suggestion before. I like it.
> 
> 
> 
> On Mon, Oct 8, 2012 at 9:20 AM, Brian Goetz <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
> 

--
Andrey Breslav
JetBrains, Inc.
http://www.jetbrains.com
"Develop with pleasure!"

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