Effectively final

[blackbelt1999]

Ahh, true, but isn't there still the fundamental difference (the original code 
creates a new thread while the new code does not)?

--Alan



________________________________
From: Neal Gafter <neal at gafter.com>
To: blackbelt1999 <blackbelt1999 at sbcglobal.net>
Cc: Steven Simpson <ss at comp.lancs.ac.uk>; lambda-dev at openjdk.java.net
Sent: Wed, September 14, 2011 11:57:02 AM
Subject: Re: Effectively final

A lambda can't modify a local variable from the enclosing scope.


On Wed, Sep 14, 2011 at 11:46 AM, blackbelt1999 <blackbelt1999 at sbcglobal.net> 
wrote:

Is there not a fundamental difference between the original code and the new
>code, namely the original code creates a new thread of execution while the new
>code does not? If so, can't the new code be simplified to:
>
>
>  void foo(final Socket socket) {
>
      boolean timedOut = false;
>
>     system.setTimeout(100, () =>  { timedOut = true; });
>     socket.onData(() =>  { if (!timedOut) System.out.println("Got data"); });
>  }
>
>The above version .does not go through the expense of creating a new object
>while providing the same behavior?
>
>--Alan
>
>
>
>
>________________________________
>From: Steven Simpson <ss at comp.lancs.ac.uk>
>To: lambda-dev at openjdk.java.net
>Sent: Wed, September 14, 2011 4:10:42 AM
>Subject: Re: Effectively final
>
>
>Just a loose end...
>
>On 15/08/11 15:41, Tim Fox wrote:
>> On 15/08/2011 15:22, Steven Simpson wrote:
>>>       void foo(final Socket socket) {
>>>         new Runnable() {
>>>           boolean timedOut;
>>>           public void run() {
>>>             system.setTimeout(100, #{ timedOut = true; });
>>>             socket.onData(#{ if (!timedOut) System.out.println("Got data");
>>});
>>>           }
>>>         }.run();
>>>       }
>> Steven, firstly thanks for putting in the effort to look at this. And
>> kudos for your ingenuity :)
>
>And yet I missed this trick!:
>
>  void foo(final Socket socket) {
>    new Object() {
>      boolean timedOut;
>      void run() {
>        system.setTimeout(100, () ->  { timedOut = true; });
>        socket.onData(() ->  { if (!timedOut) System.out.println("Got data");
>});
>      }
>    }.run();
>  }
>
>So the object doesn't have to be Runnable, and run() doesn't have to be
>public, return void, or be called run!  That's more convenient if you
>want to return a value, rather than doing tricks with Callable:
>
>  return new Object() {
>    int run() { return 0; }
>  }.run();
>
>Cheers,
>
>Steven
>
>