Feedback and comments on ARM proposal - resend

[Neal Gafter]

On Sat, Mar 14, 2009 at 7:55 PM, Howard Lovatt <howard.lovatt at iee.org> wrote:
> Instead of writing:
>
> try ( Resource r = new Resource() ) {
>  r.doSomething();
> }
>
> You would write:
>
> final Resource r = new Resource();
> r.doSomething();

I think this requires something like a new modifier on the local
variable declaration.  Without a distinguished syntax, I don't see how
to distinguish this from a normal local variable declaration.

> This is so much more Java like than the block construct, why not do
> this instead of the block construct (note it would be an error not to
> declare the resource final). r.dispose() is called at the end of the
> enclosing block, provided that r is not null, when r goes out of
> scope, which is probably what you want anyway (you can insert an
> existing {} block if you have to control lifetime). Also, why not make
> the dispose method exception free, realistically what can a user of an
> API do if dispose throws an exception?

If it's not final, what happens when the variable is reassigned?

Without allowing checked exceptions on the resource release, I don't
see how to retrofit this onto the primary use-case, Closeable.

> Neal also suggested that for each loops should understand Disposable,
> this is a good suggestion as looping is common with rources and it
> also fits well with his other suggestion above.
>
>