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Groups > comp.lang.java.programmer > #19501
| Newsgroups | comp.lang.java.programmer |
|---|---|
| Date | 2012-10-25 11:12 -0700 |
| References | (2 earlier) <mn.ab7c7dcaa9122664.70216@a.com> <k6232s$tr8$1@dont-email.me> <MPG.2af267d61a8fbe8298973b@202.177.16.121> <k69nlo$ev$1@dont-email.me> <Ts8is.2650$pn7.2130@newsfe18.iad> |
| Message-ID | <1319d1b6-821c-4a8b-8f7e-f2a7251be7cb@googlegroups.com> (permalink) |
| Subject | Re: Assigning void |
| From | Lew <lewbloch@gmail.com> |
Arved Sandstrom wrote: > Eric Sosman wrote: > [ 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". Ever since generics entered Java, thinking in terms of type theory has made sense for Java programming, not that it didn't before. Arved's analysis gives signposts for further research, at least I will take it that way. -- Lew
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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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