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Groups > comp.lang.java.programmer > #19497

Re: Assigning void

From Arved Sandstrom <asandstrom2@eastlink.ca>
Newsgroups comp.lang.java.programmer
Subject Re: Assigning void
References (1 earlier) <aegppoFqs6uU1@mid.dfncis.de> <mn.ab7c7dcaa9122664.70216@a.com> <k6232s$tr8$1@dont-email.me> <MPG.2af267d61a8fbe8298973b@202.177.16.121> <k69nlo$ev$1@dont-email.me>
Message-ID <Ts8is.2650$pn7.2130@newsfe18.iad> (permalink)
Organization Public Usenet Newsgroup Access
Date 2012-10-25 07:25 -0300

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On 10/24/2012 06:47 PM, Eric Sosman wrote:
> On 10/24/2012 4:03 PM, Wanja Gayk wrote:
>> In article <k6232s$tr8$1@dont-email.me>, Eric Sosman (esosman@comcast-
>> dot-net.invalid) says...
>>
>>>       Seriously, the fact that C permits the ?: operator with void
>>> operands is an historical accident
>>
>> Could you elaborate that in more depth please? What's so bad about it in
>> your opinion?
>
[ SNIP ]
>
>      Also, it appears that `void' is not a "type" in Java.  That
> may be a controversial position (i.e., I may have to eat my
> words), but note that `void' is not listed as a type anywhere
> in JLS 4.  The description of java.lang.Void says it's a place-
> holder for "the Java *keyword* [emphasis mine] void," not for
> a type.  So `void' has an entirely different status in Java than
> in C, where it's a full-fledged (but rather special) "type."  An
> argument that `void' in Java should behave like `void' in C seems
> to me to be on shaky ground; one might make a similar argument
> about `goto'!
>
[ SNIP ]

My reading of the JLS leads me to the same conclusion as you, that 
"void" is not a Java type (primitive). As you pointed out, it's a keyword.

I figure it's best to stay away from type theory with 'void' and 'Void'. 
Most people that do stray down this road think of Java 'void' as being 
somewhat like an empty (zero/bottom) type. But since a bottom type means 
the lack of a normal return, Java 'void' isn't probably a real empty 
type, and I've seen some folks say that it's more of a unit type. And if 
you really, really have to draw that wrapper parallel between 'void' and 
java.lang.Void, and 'Void''s' uses in reflection and generics, that 
seems to reinforce the interpretation that the unit type concept is 
perhaps more apt.

And then you've got void.class, of which the type is Class<Void>. :-)

My way of thinking about it - if type theory had to be brought into it - 
is that both 'void' and 'Void' are unit types that express "nothing that 
matters to me".

AHS

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Thread

Assigning void Wojtek <nowhere@a.com> - 2012-10-12 22:54 -0700
  Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-12 23:27 -0700
    Re: Assigning void Wojtek <nowhere@a.com> - 2012-10-13 12:35 -0700
  Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-13 09:26 -0400
  Re: Assigning void Donkey Hottie <donkey@fredriksson.dy.fi> - 2012-10-13 17:06 +0300
    Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 10:34 -0400
    Re: Assigning void Wanja Gayk <brixomatic@yahoo.com> - 2012-10-13 22:33 +0200
      Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 17:34 -0400
      Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-13 17:45 -0400
        Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-13 21:35 -0400
        Re: Assigning void Wanja Gayk <brixomatic@yahoo.com> - 2012-10-16 00:16 +0200
  Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 11:59 -0400
    Re: Assigning void glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-10-13 17:05 +0000
      Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 14:26 -0400
        Re: Assigning void markspace <-@.> - 2012-10-13 11:51 -0700
          Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 15:08 -0400
          Re: Assigning void Wojtek <nowhere@a.com> - 2012-10-13 12:28 -0700
            Re: Assigning void markspace <-@.> - 2012-10-13 12:42 -0700
              Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-13 12:54 -0700
                OT - Trolling Wojtek <nowhere@a.com> - 2012-10-13 14:16 -0700
                Re: OT - Trolling Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 18:09 -0400
                Re: OT - Trolling Gene Wirchenko <genew@ocis.net> - 2012-10-14 18:47 -0700
              Re: Assigning void Martin Gregorie <martin@address-in-sig.invalid> - 2012-10-13 20:28 +0000
              Re: Assigning void Wojtek <nowhere@a.com> - 2012-10-13 13:31 -0700
                Re: Assigning void Joerg Meier <joergmmeier@arcor.de> - 2012-10-20 18:00 +0200
                Re: Assigning void Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-10-20 09:56 -0700
                Re: Assigning void "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-10-21 13:24 +0200
                Re: Assigning void Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-10-21 10:23 -0700
                Re: Assigning void "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-10-22 00:13 +0200
                Re: Assigning void Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-10-21 16:25 -0700
                Re: Assigning void "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-10-22 08:43 +0200
                Re: Assigning void "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-10-22 10:18 +0200
                Re: Assigning void Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-10-22 08:14 -0700
                Re: Assigning void glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-10-21 19:45 +0000
                Re: Assigning void "Peter J. Holzer" <hjp-usenet2@hjp.at> - 2012-10-22 00:14 +0200
            Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-13 12:44 -0700
              Re: Assigning void Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2012-10-15 14:38 +0300
                Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-15 09:11 -0700
        Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 15:03 -0400
          Re: Assigning void glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-10-13 20:21 +0000
    Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-13 12:38 -0700
      Re: Assigning void markspace <-@.> - 2012-10-13 12:49 -0700
        Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-13 13:03 -0700
          Re: Assigning void Robert Klemme <shortcutter@googlemail.com> - 2012-10-14 14:09 +0200
            Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-14 11:31 -0700
      Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 19:55 -0400
        Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 20:25 -0400
          Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-13 21:01 -0400
            Re: Assigning void Gene Wirchenko <genew@ocis.net> - 2012-10-14 18:42 -0700
  Re: Assigning void Roedy Green <see_website@mindprod.com.invalid> - 2012-10-14 00:51 -0700
  Re: Assigning void Jeff Higgins <jeff@invalid.invalid> - 2012-10-14 10:40 -0400
  Re: Assigning void Sven Köhler <remove-sven.koehler@gmail.com> - 2012-10-21 01:24 +0200
    Re: Assigning void Wojtek <nowhere@a.com> - 2012-10-21 14:52 -0700
      Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-21 20:13 -0400
        Re: Assigning void Wojtek <nowhere@a.com> - 2012-10-21 20:20 -0700
          Re: Assigning void Sven Köhler <remove-sven.koehler@gmail.com> - 2012-10-22 11:12 +0200
        Re: Assigning void Wanja Gayk <brixomatic@yahoo.com> - 2012-10-24 22:03 +0200
          Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-24 17:47 -0400
            Re: Assigning void Wanja Gayk <brixomatic@yahoo.com> - 2012-10-25 01:02 +0200
              Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-24 20:21 -0400
                Re: Assigning void Martin Gregorie <martin@address-in-sig.invalid> - 2012-10-25 20:04 +0000
                (OT) Re: Assigning void Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-10-25 16:31 -0400
                Re: (OT) Re: Assigning void Martin Gregorie <martin@address-in-sig.invalid> - 2012-10-25 20:44 +0000
            Re: Assigning void Arved Sandstrom <asandstrom2@eastlink.ca> - 2012-10-25 07:25 -0300
              Re: Assigning void Lew <lewbloch@gmail.com> - 2012-10-25 11:12 -0700
      Re: Assigning void Sven Köhler <remove-sven.koehler@gmail.com> - 2012-10-22 11:01 +0200
      Re: Assigning void Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2012-10-23 00:38 +0200

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