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Groups > comp.lang.c > #142005
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: [ On topic, amazingtly ]: labels and declarations |
| Date | 2019-03-17 16:49 -0700 |
| Organization | None to speak of |
| Message-ID | <ln7ecxjc2n.fsf@kst-u.example.com> (permalink) |
| References | <q6lmi9$1md$1@news.xmission.com> <q6m2u6$mho$1@dont-email.me> <A4AjE.133834$y65.133545@fx44.iad> <lnbm29jdn2.fsf@kst-u.example.com> <q6ml86$6dj$1@dont-email.me> |
Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:
> Keith Thompson wrote:
>> Richard Damon <Richard@Damon-Family.org> writes:
>> [...]
>>> This unfortunately leads to the following being grammatically correct:
>>>
>>> if(flag) int x;
>>>
>>> which would mean that the following code might be valid or not depending
>>> of if flag was true at run time, or
>>>
>>> if(flag) int x;
>>> else float x;
>>>
>>> where the type of x changes at run time, or even
>> [...]
>>
>> C++ allows this; a declaration (if it appears inside a function
>> defintion) is a kind of statement. The scope of x is limited to the
>> declaration-statement, so the above is equivalent to:
>>
>> if (flag) { int x; }
>> else { float x; }
>>
>> which is valid in C.
>
> By implication, even current C supports this, afaict. Consider
>
> if (!flag) goto label1;
> int x;
> goto label2;
> label1: ;
> float x;
> label2: ;
>
> Doesn't this accomplish the same end-state as Richard's
> if(flag) int x;
> else float x;
> ?
No. In your example with gotos, the declaration `float x;` is illegal,
because there's already an `x` defined in the same scope.
In Richard's example, if the scopes of the two `x`s extended beyond the
if-else statement, it would be difficult to define the semantics or,
more likely, the second declaration would be illegal for the same
reason. If the scopes were defined as they are in C++, they would be
non-overlapping and unambiguous (and not useful, since nothing could
refer to either `x`).
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
void Void(void) { Void(); } /* The recursive call of the void */
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[ On topic, amazingtly ]: labels and declarations gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-17 14:45 +0000
Re: [ On topic, amazingtly ]: labels and declarations nobody@example.org (Scott) - 2019-03-17 17:25 +0000
Re: [ On topic, amazingtly ]: labels and declarations fir is a sexy shemale <cdalten@gmail.com> - 2019-03-17 10:59 -0700
Re: [ On topic, amazingtly ]: labels and declarations Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2019-03-17 14:16 -0400
Re: [ On topic, amazingtly ]: labels and declarations Richard Damon <Richard@Damon-Family.org> - 2019-03-17 18:43 -0400
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-17 22:55 +0000
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 01:37 +0000
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-17 19:46 -0700
Re: [ On topic, amazingtly ]: labels and declarations David Brown <david.brown@hesbynett.no> - 2019-03-18 08:41 +0100
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 11:20 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 04:39 -0700
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 12:08 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 05:26 -0700
labels and declarations and debugger breakpoints "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 05:40 -0700
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 17:25 +0000
Re: [ On topic, amazingtly ]: labels and declarations gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-18 19:11 +0000
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-19 01:36 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 12:31 -0700
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 19:57 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 13:09 -0700
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 21:09 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 16:03 -0700
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 23:49 +0000
Re: [ On topic, amazingtly ]: labels and declarations fir is a sexy shemale <cdalten@gmail.com> - 2019-03-18 16:53 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 18:03 -0700
Re: [ On topic, amazingtly ]: labels and declarations David Brown <david.brown@hesbynett.no> - 2019-03-18 13:16 +0100
Re: [ On topic, amazingtly ]: labels and declarations Bart <bc@freeuk.com> - 2019-03-18 12:30 +0000
Re: [ On topic, amazingtly ]: labels and declarations David Brown <david.brown@hesbynett.no> - 2019-03-18 13:41 +0100
Re: [ On topic, amazingtly ]: labels and declarations fir <profesor.fir@gmail.com> - 2019-03-18 06:54 -0700
Re: [ On topic, amazingtly ]: labels and declarations fir <profesor.fir@gmail.com> - 2019-03-18 07:05 -0700
Re: [ On topic, amazingtly ]: labels and declarations fir <profesor.fir@gmail.com> - 2019-03-18 09:07 -0700
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-18 06:46 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 07:25 -0700
Re: [ On topic, amazingtly ]: labels and declarations Manfred <noname@add.invalid> - 2019-03-21 17:48 +0100
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-21 10:04 -0700
Re: [ On topic, amazingtly ]: labels and declarations fir is a sexy shemale <cdalten@gmail.com> - 2019-03-21 10:34 -0700
Re: [ On topic, amazingtly ]: labels and declarations Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-03-21 20:19 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-21 14:29 -0700
Re: [ On topic, amazingtly ]: labels and declarations Chad <cdalten@gmail.com> - 2019-03-22 10:15 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-22 13:58 -0700
Re: [ On topic, amazingtly ]: labels and declarations Chad <cdalten@gmail.com> - 2019-03-22 15:10 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-22 15:31 -0700
Re: [ On topic, amazingtly ]: labels and declarations David Brown <david.brown@hesbynett.no> - 2019-03-22 09:22 +0100
Re: [ On topic, amazingtly ]: labels and declarations Chad <cdalten@gmail.com> - 2019-03-22 09:28 -0700
Re: [ On topic, amazingtly ]: labels and declarations Manfred <invalid@add.invalid> - 2019-03-22 18:15 +0100
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-22 10:51 -0700
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-22 11:31 -0700
Re: [ On topic, amazingtly ]: labels and declarations Manfred <noname@add.invalid> - 2019-03-23 17:43 +0100
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-23 13:36 -0700
Re: [ On topic, amazingtly ]: labels and declarations Richard Damon <Richard@Damon-Family.org> - 2019-03-23 17:37 -0400
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-25 09:18 -0700
Re: [ On topic, amazingtly ]: labels and declarations James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-22 12:59 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-22 14:03 -0700
Re: [ On topic, amazingtly ]: labels and declarations David Brown <david.brown@hesbynett.no> - 2019-03-23 12:44 +0100
Re: [ On topic, amazingtly ]: labels and declarations Robert Wessel <robertwessel2@yahoo.com> - 2019-03-24 10:10 -0500
Re: [ On topic, amazingtly ]: labels and declarations Manfred <noname@add.invalid> - 2019-03-23 17:48 +0100
Re: [ On topic, amazingtly ]: labels and declarations James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-25 11:32 -0700
Re: [ On topic, amazingtly ]: labels and declarations Robert Wessel <robertwessel2@yahoo.com> - 2019-03-21 22:22 -0500
Re: [ On topic, amazingtly ]: labels and declarations Manfred <noname@add.invalid> - 2019-03-22 17:45 +0100
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-22 11:13 -0700
Re: [ On topic, amazingtly ]: labels and declarations Manfred <noname@add.invalid> - 2019-03-23 18:20 +0100
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-23 11:57 -0700
Re: [ On topic, amazingtly ]: labels and declarations James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-25 10:58 -0700
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-25 13:17 -0700
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-17 16:16 -0700
Re: [ On topic, amazingtly ]: labels and declarations Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2019-03-17 19:29 -0400
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-17 16:49 -0700
Re: [ On topic, amazingtly ]: labels and declarations Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2019-03-17 19:51 -0400
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-17 17:41 -0700
Re: [ On topic, amazingtly ]: labels and declarations Richard Damon <Richard@Damon-Family.org> - 2019-03-17 22:53 -0400
Re: [ On topic, amazingtly ]: labels and declarations Keith Thompson <kst-u@mib.org> - 2019-03-17 21:08 -0700
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-17 21:40 -0700
Re: [ On topic, amazingtly ]: labels and declarations gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-18 05:03 +0000
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 02:30 -0700
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-18 06:32 -0700
Re: [ On topic, amazingtly ]: labels and declarations gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-18 16:06 +0000
Re: [ On topic, amazingtly ]: labels and declarations Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-03-17 22:19 -0700
Re: [ On topic, amazingtly ]: labels and declarations Richard Damon <Richard@Damon-Family.org> - 2019-03-17 20:07 -0400
Re: [ On topic, amazingtly ]: labels and declarations luser droog <luser.droog@gmail.com> - 2019-03-17 12:37 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-18 11:00 +0800
Re: [ On topic, amazingtly ]: labels and declarations "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-18 22:43 +0800
Re: [ On topic, amazingtly ]: labels and declarations "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-18 08:00 -0700
Re: [ On topic, amazingtly ]: labels and declarations "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 13:11 +0800
Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-19 05:27 +0000
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 14:40 +0800
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-19 04:39 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 19:44 +0800
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 05:11 -0700
Re: Use of goto in high-level C programming "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 20:13 +0800
Re: Use of goto in high-level C programming fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 05:42 -0700
Re: Use of goto in high-level C programming "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 20:44 +0800
Re: Use of goto in high-level C programming Wouter Verhelst <w@uter.be> - 2019-03-20 08:16 +0200
Re: Use of goto in high-level C programming "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-20 19:16 +0800
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 05:13 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-19 05:56 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 06:30 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-19 06:54 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 07:12 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2019-03-19 12:03 -0700
Re: Telling Fred where to go... (Was: [ On topic, amazingtly ]: labels and declarations) fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 13:33 -0700
Re: [ On topic, amazingtly ]: labels and declarations fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 05:17 -0700
Re: from programming to religion and then.... sex? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 20:23 +0800
Re: from programming to religion and then.... sex? fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 05:40 -0700
Re: from programming to religion and then.... sex? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 20:46 +0800
Re: from programming to religion and then.... sex? fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 06:30 -0700
Re: from programming to religion and then.... sex? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-19 21:36 +0800
Re: from programming to religion and then.... sex? fir is a sexy shemale <cdalten@gmail.com> - 2019-03-19 07:08 -0700
Re: from programming to religion and then.... sex? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2019-03-20 19:16 +0800
Re: [ On topic, amazingtly ]: labels and declarations John Bode <jfbode1029@gmail.com> - 2019-03-19 14:58 -0700
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