JDK-8300691 - final variables in for loop headers should accept updates

[Archie Cobbs]

On Fri, Oct 25, 2024 at 10:02 AM Archie Cobbs <archie.cobbs at gmail.com>
wrote:

> Is there some quasi-consensus to go forward with this idea for fixing
> basic for() loops?
>

(Hmm, nobody responded yes and nobody responded no...)

Now that JDK 24 is out of the way, I'd like to get some kind of final
adjudication on whether to continue pursuing this idea from this list.

If everyone is good with doing this then I'm happy to continue working on
it, otherwise I'm happy to shelve it. I would just like to tie up the loose
end one way or another.

To recap: the idea is to allow loop variables declared in basic (old style)
for() loops to be captured in the body of the loop as long as they are not
reassigned in the body of the loop (but they may be reassigned in the loop
step). For example:

for (int i = 1; i <= 3; i++) {
    Runnable r = () -> System.out.println(i);   // allow this
}

There was lots of good discussion and we did narrow down the idea to what's
described above. However I'm unclear on whether to now proceed with asking
for additional reviews, etc. and don't want to presume.

If nobody replies I won't ask again :)

FWIW here's what has been drafted so far (all subject to improvement of
course):

Bug: https://bugs.openjdk.org/browse/JDK-8341782
CSR: https://bugs.openjdk.org/browse/JDK-8341783
JEP: https://bugs.openjdk.org/browse/JDK-8341785
JLS: https://bugs.openjdk.org/browse/JDK-8341786
PR: https://github.com/openjdk/jdk/pull/21415

Thanks,
-Archie

-- 
Archie L. Cobbs
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