Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | Tim Rentsch <txr@alumni.caltech.edu> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: just curious:Equel |
| Date | 2015-09-08 10:49 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <kfntwr4ls2o.fsf@x-alumni2.alumni.caltech.edu> (permalink) |
| References | (2 earlier) <87d1y0j22l.fsf@bsb.me.uk> <20344006-862c-4bab-9fb8-3702d5acd6a4@googlegroups.com> <wrFFx.2$Bw.1@fx17.am4> <kfnd1xvp3qo.fsf@x-alumni2.alumni.caltech.edu> <lnk2s3t6no.fsf@kst-u.example.com> |
Keith Thompson <kst-u@mib.org> writes:
> Tim Rentsch <txr@alumni.caltech.edu> writes:
>> Richard Heathfield <rjh@cpax.org.uk> writes:
>>> On 02/09/2015 16:12, Rick C. Hodgin wrote:
>>>
>>>> What are "C objects?"
>>>
>>> 3.14 says: "region of data storage in the execution environment, the
>>> contents of which can represent
>>> values".
>>>
>>> For example, in this program:
>>>
>>> #include <stdio.h>
>>>
>>> int main(void)
>>> {
>>> int i;
>>> for(i = 0; i < 10; i++)
>>> {
>>> printf("%d\n", i);
>>> }
>>> return 0;
>>> }
>>>
>>> i is an object. [snip]
>>
>> i is an identifier. In this function definition the identifier i
>> refers to an object (and may refer to more than one, for a
>> function that might have multiple instantiations), but its
>> an abuse of teminology to say i is an object.
>
> Tim is a sequence of three ASCII characters. Tim is a name.
> Is it an "abuse of terminology" to say that Tim is a person?
If the statement is made in a context where it is important
to be technically precise, then Yes, it is.
> The C standard routinely refers to objects by their names.
I expect it does, but the context for those statements is
different, so the distinction is not so important in those
cases.
> The first
> example I happened to run across is in N1570 6.7.2.1p20 (an example)
> which refers to "the object pointed to by p". Clearly an identifier
> does not point to an object; equally clearly, when the standard says
> "p", it means "the pointer object whose name is the identifier p".
I would say "the object pointed to by p" means "the object
pointed to by the value held in the variable p", or perhaps "the
object pointed to by the value held in the object referred to
by the identifier p". I don't think of objects as "having"
names; in some cases we use an identifier to refer to an
object, but that doesn't give the object "ownership" of the
name, it's the other way around. In any case all that is
pretty much beside the point, which is that this text assumes
a different context where the distinction between object and
identifier is presumed to be already understood. When someone
is asking for an explanation of what an object is, we should
assume the distinction between an identifier and an object
is /not/ already understood, which makes it important to
highlight the distinction.
> Things have names precisely so we can refer to them by those names.
That is true in some cases but not all cases. That observation
is especially important in C, where the relationship between
identifiers and objects is nowhere near one-to-one.
> We can add clarifying wording when it's necessary to avoid confusion
> (for example to distinguish between you and someone else named Tim);
> there is no such need in this case.
I emphatically disagree. When someone is asking for an
explanation of what an object (in C) is, it is very important
to highlight subtle distinctions, like that of object and an
identifier that is used to refer to an object. To gloss over
that distinction is doing a severe disservice to both the
questioner and the explnation.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
just curious:Equel G G <gdotone@gmail.com> - 2015-09-01 22:37 -0700
Re: just curious:Equel James Kuyper <jameskuyper@verizon.net> - 2015-09-02 09:56 -0400
Re: just curious:Equel Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-02 16:03 +0100
Re: just curious:Equel "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-02 08:12 -0700
Re: just curious:Equel gordonb.d8f7l@burditt.org (Gordon Burditt) - 2015-09-02 11:09 -0500
Re: just curious:Equel Richard Heathfield <rjh@cpax.org.uk> - 2015-09-02 17:27 +0100
Re: just curious:Equel "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-02 09:36 -0700
Re: just curious:Equel Richard Heathfield <rjh@cpax.org.uk> - 2015-09-02 17:57 +0100
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-02 22:34 +0200
Re: just curious:Equel Richard Heathfield <rjh@cpax.org.uk> - 2015-09-02 21:48 +0100
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-03 09:31 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 13:29 -0700
Re: just curious:Equel James Kuyper <jameskuyper@verizon.net> - 2015-09-02 17:09 -0400
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 13:33 -0700
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 12:56 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-07 10:57 +0200
Re: just curious:Equel Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-09-07 19:29 +0000
Re: just curious:Equel James Kuyper <jameskuyper@verizon.net> - 2015-09-07 15:49 -0400
Re: just curious:Equel Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-09-10 16:44 +0000
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-07 23:12 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-08 10:35 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-09 10:22 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-10 10:21 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-11 12:06 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-12 17:53 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-26 16:04 -0700
Re: just curious:Equel Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-26 16:17 -0700
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-01 12:53 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-28 18:00 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-10-01 12:51 -0700
Re: just curious:Equel Philip Lantz <prl@canterey.us> - 2015-09-23 22:18 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-24 10:08 +0200
Re: just curious:Equel Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-24 10:23 +0100
Re: just curious:Equel Philip Lantz <prl@canterey.us> - 2015-09-24 10:28 -0700
Re: just curious:Equel Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-24 19:56 +0100
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-26 16:16 -0700
Re: just curious:Equel August Karlstrom <fusionfile@gmail.com> - 2015-09-28 08:18 +0200
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-26 16:10 -0700
Re: just curious:Equel supercat@casperkitty.com - 2015-09-27 11:40 -0700
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-29 10:03 -0700
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 13:25 -0700
Re: just curious:Equel Ike Naar <ike@iceland.freeshell.org> - 2015-09-07 09:14 +0000
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 15:44 -0700
Re: just curious:Equel Keith Thompson <kst-u@mib.org> - 2015-09-06 17:27 -0700
Re: just curious:Equel Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-08 10:49 -0700
Re: just curious:Equel James Kuyper <jameskuyper@verizon.net> - 2015-09-02 11:49 -0400
Re: just curious:Equel Jay Braun <lyngwyst@gmail.com> - 2015-09-02 13:02 -0700
Re: just curious:Equel "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-02 13:08 -0700
Re: just curious:Equel G G <gdotone@gmail.com> - 2015-09-02 16:10 -0700
Re: just curious:Equel Bartc <bc@freeuk.com> - 2015-09-02 21:30 +0100
Re: just curious:Equel "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-02 13:37 -0700
Re: just curious:Equel Jay Braun <lyngwyst@gmail.com> - 2015-09-02 13:44 -0700
Re: just curious:Equel "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-09-02 13:52 -0700
Re: just curious:Equel G G <gdotone@gmail.com> - 2015-09-02 16:07 -0700
Re: just curious:Equel Andreas Perstinger <andipersti@gmail.com> - 2015-09-03 08:49 +0000
Re: just curious:Equel Bartc <bc@freeuk.com> - 2015-09-03 10:47 +0100
Re: just curious:Equel G G <gdotone@gmail.com> - 2015-09-02 16:17 -0700
csiph-web