From: http://jeremymanson.blogspot.com/2009/02/small-language-changes-for-jdk7.html

Automated Resource Blocks, to be able to say things like:

try (BufferedReader br = new BufferedReader(new FileReader(path)) {
  return br.readLine();
}

instead of:

BufferedReader br = new BufferedReader(new FileReader(path));
try {
   return br.readLine();
} finally {
   br.close();
}

based on having BufferedReader implement a Disposable interface.

------------------

Exception handling improvements:

try {
    doWork(file);
} catch (final IOException | SQLException ex) {
    logger.log(ex);
    throw ex;
}

Bye,
bearophile

在 Mon, 02 Mar 2009 08:02:35 +0800，bearophile <bearophileHUGS@lycos.com> 写道:

> From:
> http://jeremymanson.blogspot.com/2009/02/small-language-changes-for-jdk7.html
>
> Automated Resource Blocks, to be able to say things like:
>
> try (BufferedReader br = new BufferedReader(new FileReader(path)) {
>   return br.readLine();
> }
>
> instead of:
>
> BufferedReader br = new BufferedReader(new FileReader(path));
> try {
>    return br.readLine();
> } finally {
>    br.close();
> }
>
> based on having BufferedReader implement a Disposable interface.
>
> ------------------
>
> Exception handling improvements:
>
> try {
>     doWork(file);
> } catch (final IOException | SQLException ex) {
>     logger.log(ex);
>     throw ex;
> }
>
> Bye,
> bearophile

I believe it is worse than scope(exit) resource.dispose(); in terms of syntax.

davidl wrote:
> 在 Mon, 02 Mar 2009 08:02:35 +0800，bearophile <bearophileHUGS@lycos.com> 写道:
> 
>> From:
>> http://jeremymanson.blogspot.com/2009/02/small-language-changes-for-jdk7.html 
>>
>>
>> Automated Resource Blocks, to be able to say things like:
>>
>> try (BufferedReader br = new BufferedReader(new FileReader(path)) {
>>   return br.readLine();
>> }
>>
>> instead of:
>>
>> BufferedReader br = new BufferedReader(new FileReader(path));
>> try {
>>    return br.readLine();
>> } finally {
>>    br.close();
>> }
>>
>> based on having BufferedReader implement a Disposable interface.
>>
>> ------------------
>>
>> Exception handling improvements:
>>
>> try {
>>     doWork(file);
>> } catch (final IOException | SQLException ex) {
>>     logger.log(ex);
>>     throw ex;
>> }
>>
>> Bye,
>> bearophile
> 
> I believe it is worse than scope(exit) resource.dispose(); in terms of syntax.

I agree. They keep on missing the point that the blessed code on the normal path MUST NOT TAKE THE HIT OF AN EXTRA INDENTATION LEVEL. I am screaming because people keep on falling in that trap in various languages, mostly by copying without thinking from other languages. The first language I know that did that mistake was Lisp itself.

Andrei

bearophile wrote:
> From:
> http://jeremymanson.blogspot.com/2009/02/small-language-changes-for-jdk7.html
> 
> Automated Resource Blocks, to be able to say things like:

Reinventing scope, rather badly.

Walter Bright:
> Reinventing scope, rather badly.

Python has recently introduced something similar to that Java solution: http://www.python.org/dev/peps/pep-0343/

Bye,
bearophile

On Mon, Mar 2, 2009 at 3:57 PM, bearophile <bearophileHUGS@lycos.com> wrote:
> Walter Bright:
>> Reinventing scope, rather badly.
>
> Python has recently introduced something similar to that Java solution: http://www.python.org/dev/peps/pep-0343/

Does that change the fact that it's a poor imitation of scope?

Walter Bright wrote:

> bearophile wrote:
>> From: http://jeremymanson.blogspot.com/2009/02/small-language-changes-for-
jdk7.html
>> 
>> Automated Resource Blocks, to be able to say things like:
> 
> Reinventing scope, rather badly.

It looks more like (or rather exactly like) C#'s using.

http://www.boost.org/doc/libs/1_38_0/libs/scope_exit/doc/html/scope_exit/alternatives.html

try
{
    File passwd("/etc/passwd");
    BOOST_SCOPE_EXIT( (&passwd) )
    {
        passwd.close();
    } BOOST_SCOPE_EXIT_END
    // ...
}
catch(...)
{
    log("could not get user info");
    throw;
}