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Groups > comp.lang.java.programmer > #22364

Re: abbreviated generic syntax

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Roedy Green <see_website@mindprod.com.invalid> wrote:
> On Mon, 18 Feb 2013 12:29:53 -0800 (PST), Lew <lewbloch@gmail.com>
> wrote, quoted or indirectly quoted someone who said :
>> The diamond operator distinguishes the generics usage.
> OK, that is obvious, but would it break any code?

I'm not taking the time to think it all through to the end, 
but "fwiw":

To see any technical difference between the two patterns:
 Base<Type> b = new Sub<>();
and
 Base<Type> b = new Sub();

You might want to consider different subclasses of some class, 
where one is itself generic and the other is not:
  interface Base<T> { ... } 
  class Sub1<T> implements Base<T> { ... }
  class Sub2 implements Base<String> { ... }

Most likely(*), it is currently *not* legal to write:
  Base<String> b = new Sub2<>();

So, the compiler probably shouldn't *always* assume the <>
to a pattern like:   Base<Type> b = new SubClass();

In how far it would be always possible for the compiler to
check the referenced class first (to see if it is generic
and if so then just assume the diamond), I can't tell.

PS:
*: I did not care enough to check the JLS or even try it.

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abbreviated generic syntax Roedy Green <see_website@mindprod.com.invalid> - 2013-02-17 20:26 -0800
  Re: abbreviated generic syntax Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-02-18 01:02 -0800
  Re: abbreviated generic syntax Barb Knox <see@sig.below> - 2013-02-18 22:41 +1300
    Re: abbreviated generic syntax Donkey Hottie <donkey@fredriksson.dy.fi> - 2013-02-18 12:58 +0200
    Re: abbreviated generic syntax Arne Vajhoej <arne@vajhoej.dk> - 2013-02-18 07:20 -0500
      Re: abbreviated generic syntax Arne Vajhoej <arne@vajhoej.dk> - 2013-02-18 07:27 -0500
  Re: abbreviated generic syntax Arne Vajhoej <arne@vajhoej.dk> - 2013-02-18 07:23 -0500
  Re: abbreviated generic syntax "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2013-02-18 19:33 +0000
  Re: abbreviated generic syntax BGB <cr88192@hotmail.com> - 2013-02-18 13:46 -0600
  Re: abbreviated generic syntax Lew <lewbloch@gmail.com> - 2013-02-18 12:29 -0800
    Re: abbreviated generic syntax Robert Klemme <shortcutter@googlemail.com> - 2013-02-18 22:49 +0100
      Re: abbreviated generic syntax Lew <lewbloch@gmail.com> - 2013-02-18 13:51 -0800
    Re: abbreviated generic syntax Roedy Green <see_website@mindprod.com.invalid> - 2013-02-18 15:35 -0800
      Re: abbreviated generic syntax lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-02-19 08:56 +0000
        Re: abbreviated generic syntax lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-02-19 12:30 +0000
      Re: abbreviated generic syntax Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-02-19 16:21 +0000
      Re: abbreviated generic syntax Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-02-19 11:38 -0600
      Re: abbreviated generic syntax Arne Vajhoej <arne@vajhoej.dk> - 2013-02-19 12:45 -0500
        Re: abbreviated generic syntax BGB <cr88192@hotmail.com> - 2013-02-19 15:20 -0600

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