JEP proposed to target JDK 11: 323: Local-Variable Syntax for Lambda Parameters

[Jonathan Bluett-Duncan]

Hmm, is that not what variables like the following are for?

Function<@Nullable Integer, @Nonnull Integer> function = x -> (x == null) ?
0 : x + 1;

On 26 January 2018 at 09:59, Zheka Kozlov <orionllmain at gmail.com> wrote:

> The motivation is to allow `final` and annotations on lambda parameters:
>
> (final var x) → x + 1;
> (@Nonnull var x) → x + 1;
>
> This is impossible to write with an implicitly typed lambda:
>
> (final x) → x + 1; // Illegal
> (@Nonnull x) → x + 1; // Illegal
>
>
> 2018-01-26 15:30 GMT+07:00 Martijn Verburg <martijnverburg at gmail.com>:
>
> > Hi all,
> >
> > I'm struggling to understand the motivation for this JEP in terms of it
> > adding improved understanding or readability of source code (as the
> > implicit case is already covered today).
> >
> > I also suspect the illegal use uses (extract below) will likely confuse
> and
> > frustrate day to day developer's who don't understand the underlying type
> > inference system and lead to
> > some heavily upvoted SO Q's.  I liken this type of frustration seen in
> > developers not understanding generics in full and coming undone in corner
> > cases where they expect the element of
> > 'least surprise'.
> >
> > ------
> >
> > The following examples are illegal:
> >
> > (var x, y) -> x + y        // Cannot mix var and "no var" in
> > implicitly typed lambda expression
> > (var x, int y) -> x + y    // Cannot mix var and manifest types in
> > explicitly typed lambda expression
> >
> >
> > -------
> >
> > I'm not sure I've explained myself very eloquently here, hope this has
> made
> > some sense.
> >
> > Cheers,
> > Martijn
> >
> > On 26 January 2018 at 08:40, <mark.reinhold at oracle.com> wrote:
> >
> > > The following JEP is proposed to target JDK 11:
> > >
> > >   323: Local-Variable Syntax for Lambda Parameters
> > >        http://openjdk.java.net/jeps/323
> > >
> > > Feedback on this proposal is more than welcome, as are reasoned
> > > objections.  If no such objections are raised by 23:00 UTC on Thursday,
> > > 1 February, or if they're raised and then satisfactorily answered, then
> > > per the JEP 2.0 process proposal [1] I'll target this JEP to JDK 11.
> > >
> > > - Mark
> > >
> > >
> > > [1] http://cr.openjdk.java.net/~mr/jep/jep-2.0-02.html
> > >
> >
>