On 01/16/2015 06:46 PM, Ivan Gerasimov wrote:
Might it also make sense to allow anonymous variables in the
try-with-resource statement?
So that something like `try (() -> System.out.println("closed")) {}`
would work...
I don't think that is necessary. In JDK 7, we started out allowing a
general AutoCloseable expression in a try-with-resources statement
and that proved problematic. Supporting a final / effectively final
variable seems to be the right balance. The rationale is written up
in the JSR 334 materials.
Yes, I agree. And it can easily be moved to the finally block, of course.
However, this:
ExecutorService executor = ...;
try (executor::shutdown) {
}
still looks a bit more attractive to me, comparing to `try (Closeable
c = executor::shutdown) {`
Maybe one day ... :-)
Sincerely yours,
Ivan
If try-with resources was designed after lambdas, various other forms
could be considered. For example, the following:
try (SomeType var = expression; expression with (target) type Consumer<?
super SomeType>) {
...
}
The example with ExecutorService would then read:
try (ExecutorService executor = Executors.newCachedThreadPool();
ExecutorService::shutdown) {
... use executor ...
}
This could even be done in the future as the 2nd form of
try-with-resources. Maybe one day ... :-)
Peter
