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| From | Ben Bacarisse <ben.usenet@bsb.me.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Is there any place to talk about language features? |
| Date | 2016-10-01 19:52 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <878tu76gwq.fsf@bsb.me.uk> (permalink) |
| References | (13 earlier) <c7787c1f-f39c-499f-8d93-1caa13d4c005@googlegroups.com> <e59h3bFkp66U1@mid.individual.net> <a3ba260b-f6ab-4677-9073-c7c9866c7232@googlegroups.com> <87k2ds5ekn.fsf@bsb.me.uk> <25ce313b-434c-4289-8c3d-51e15f1e40af@googlegroups.com> |
Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
> On Saturday, October 1, 2016 at 3:28:17 PM UTC+1, Ben Bacarisse wrote:
>> Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
>>
>> > On Saturday, October 1, 2016 at 11:22:42 AM UTC+1, Ian Collins wrote:
>> <snip>
>> >> You overlook the fact that many if not most resource allocation and
>> >> release happens in different parts of a programme.
>> >>
>> > There's also the structure pattern. A graph is created, then nodes and
>> > edges are added and deleted as the algorithm does its stuff. So
>> > obviously memory has to be allocated at the point a node is created
>> > and released at the point it is destroyed. But everything should
>> > be accessible from the root, and at every time it ought to be
>> > possible to destroy the entire structure by calling the destructor
>> > on the root.
>> >
>> > The trick is to use structured programming. Each "block" (which is
>> > similar to but not identical to a C curly braces block") has one
>> > point of entry and one point of exit. So creation and destruction
>> > are matched. A block either destroys all the resources it holds
>> > on exit, or passes them up to caller. If it passes them up to caller,
>> > it must be matched by a "destructor" function, which caller must
>> > call on his own exit (or pass them up to super-caller, and provide
>> > a destructor of his own, which then calls the destructor).
>>
>> This pattern does not always work. You can't always have nested
>> creation and deletion like this. A Lisp implementation comes to mind as
>> an example. (Actually it may be possible to enforce this at the expense
>> of a great deal of copying but I'm not sure even that is possible.)
>>
> Firstly toplevel will be
>
> int lisp(void)
> {
> LISPENGINE *lisp = 0;
> int err = 0;
>
> lisp = creatlispengine("myprogam.((())))");
> if(!lisp)
> goto error_exit;
>
> do
> {
> halted = lisp_runastep(lisp, &err);
> if(err)
> goto error_exit;
> } while(!halted);
>
> killlispeengine(lisp);
> return 0;
>
> error_exit:
> killlispengine(lisp);
> return -1;
> }
>
>
> So that's not problematic,
What's not problematic? The code above is fine (except for a
disagreement about style) but that's because it doesn't illustrate the
problem.
The problem is not wasting space by deleting objects at the end of their
lifetime but whose lifetime does not correspond to the (dynamic) nesting
of function calls in the C program.
> the only difficulty is that lisp_runastep()
> does not return anything except a halt flag in normal execution,
> but may run out of memory or experience IO failure internally, in
> which case it needs to pass the error up to abort.
I don't see why that's a difficulty at all (though I'd probably put the
error state into the lisp engine object).
--
Ben.
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Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 09:35 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-09-28 09:39 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 09:46 -0700
Re: Is there any place to talk about language features? Richard Heathfield <rjh@cpax.org.uk> - 2016-09-28 17:53 +0100
Re: Is there any place to talk about language features? David Brown <david.brown@hesbynett.no> - 2016-09-28 21:21 +0200
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-09-28 20:36 +0100
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 13:55 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 14:02 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-09-29 10:03 +1300
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 14:13 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-09-29 10:22 +1300
Re: Is there any place to talk about language features? Robert Latest <boblatest@yahoo.com> - 2016-10-03 08:47 +0000
Re: Is there any place to talk about language features? James Kuyper <jameskuyper@verizon.net> - 2016-10-03 07:44 -0400
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 04:56 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-03 13:18 +0100
Re: Is there any place to talk about language features? BGB <cr88192@hotmail.com> - 2016-10-03 12:43 -0500
Re: Is there any place to talk about language features? Ike Naar <ike@iceland.freeshell.org> - 2016-10-03 21:43 +0000
Re: Is there any place to talk about language features? John Gordon <gordon@panix.com> - 2016-10-03 22:28 +0000
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-03 04:51 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-03 13:10 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 05:48 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-03 14:03 +0100
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-03 14:24 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 07:07 -0700
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-03 19:16 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 07:16 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-03 07:45 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-03 07:57 -0700
Re: Is there any place to talk about language features? James Kuyper <jameskuyper@verizon.net> - 2016-10-03 08:21 -0400
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-03 05:31 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-03 06:43 -0700
Re: Is there any place to talk about language features? David Brown <david.brown@hesbynett.no> - 2016-10-03 15:08 +0200
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 14:22 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-09-28 15:16 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 16:08 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-09-28 16:57 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-09-28 14:19 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 14:50 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 17:03 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-09-29 01:08 +0100
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-28 17:33 -0700
Re: Is there any place to talk about language features? Melzzzzz <Melzzzzz@zzzzz.com> - 2016-09-29 01:02 +0000
Re: Is there any place to talk about language features? BGB <cr88192@hotmail.com> - 2016-09-29 01:39 -0500
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-09-29 00:48 -0700
Re: Is there any place to talk about language features? BGB <cr88192@hotmail.com> - 2016-09-29 11:59 -0500
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-01 08:09 +1300
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-30 12:14 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-01 09:07 +1300
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-30 13:53 -0700
Re: Is there any place to talk about language features? Gareth Owen <gwowen@gmail.com> - 2016-09-30 22:13 +0100
Re: Is there any place to talk about language features? raltbos@xs4all.nl (Richard Bos) - 2016-10-01 09:36 +0000
Re: Is there any place to talk about language features? Jerry Stuckle <jstucklex@attglobal.net> - 2016-10-01 13:04 -0400
Re: Is there any place to talk about language features? "Chris M. Thomasson" <invalid@invalid.invalid> - 2016-09-30 14:20 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-09-30 22:30 +0100
Re: Is there any place to talk about language features? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2016-10-02 07:30 +0000
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-01 01:51 -0700
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-01 10:31 +0100
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-01 23:22 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-01 06:15 -0700
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-01 15:28 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-01 10:07 -0700
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-01 19:52 +0100
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-02 20:38 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-02 03:37 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-03 08:35 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-02 15:17 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-03 18:29 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 01:09 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-04 08:21 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-03 13:12 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-03 14:34 -0700
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-04 00:47 -0700
Re: Is there any place to talk about language features? Ike Naar <ike@iceland.freeshell.org> - 2016-10-04 07:49 +0000
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-04 07:50 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-10-04 08:57 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-04 10:42 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-05 15:47 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-04 20:58 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-05 18:14 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 02:15 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-05 22:44 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 03:12 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 15:38 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 19:50 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 16:25 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 21:19 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 18:11 +1300
Re: Is there any place to talk about language features? Gareth Owen <gwowen@gmail.com> - 2016-10-06 06:38 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-06 00:36 -0700
Re: Is there any place to talk about language features? gwowen <gwowen@gmail.com> - 2016-10-06 07:33 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-06 09:00 -0700
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-07 00:32 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-07 05:05 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-07 08:13 -0700
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-07 00:20 -0700
Re: Is there any place to talk about language features? Gareth Owen <gwowen@gmail.com> - 2016-10-07 17:01 +0100
Re: Is there any place to talk about language features? Les Cargill <lcargill99@comcast.com> - 2016-10-05 12:45 -0500
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-05 11:12 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 03:15 -0700
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-05 14:41 +0100
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 08:01 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-05 08:41 -0700
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 10:29 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-05 12:29 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-05 11:08 +0100
Re: Is there any place to talk about language features? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-10-05 14:35 +0100
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-05 18:15 +0100
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-05 10:38 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-05 19:14 +0100
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-05 11:56 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-05 11:57 -0700
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-10-05 12:18 -0700
Re: Is there any place to talk about language features? David Brown <david.brown@hesbynett.no> - 2016-10-05 21:49 +0200
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-10-05 13:07 -0700
Re: Is there any place to talk about language features? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-10-05 16:23 -0400
Re: Is there any place to talk about language features? David Brown <david.brown@hesbynett.no> - 2016-10-06 14:26 +0200
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-05 13:56 -0700
Re: Is there any place to talk about language features? BartC <bc@freeuk.com> - 2016-10-06 14:17 +0100
Re: Is there any place to talk about language features? David Brown <david.brown@hesbynett.no> - 2016-10-06 15:53 +0200
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-10-06 09:12 -0700
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-06 11:28 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 15:31 +1300
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 15:32 +1300
Re: Is there any place to talk about language features? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-10-05 19:43 -0700
Re: Is there any place to talk about language features? Ian Collins <ian-news@hotmail.com> - 2016-10-06 16:05 +1300
Re: Is there any place to talk about language features? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2016-10-02 07:24 +0000
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-09-30 16:17 -0700
Re: Is there any place to talk about language features? raltbos@xs4all.nl (Richard Bos) - 2016-10-01 09:39 +0000
Re: Is there any place to talk about language features? supercat@casperkitty.com - 2016-10-01 14:11 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-29 07:47 -0700
Re: Is there any place to talk about language features? Thiago Adams <thiago.adams@gmail.com> - 2016-09-29 10:25 -0700
Re: Is there any place to talk about language features? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-09-28 12:59 -0400
Re: Is there any place to talk about language features? Richard Heathfield <rjh@cpax.org.uk> - 2016-09-28 18:30 +0100
Re: Is there any place to talk about language features? Keith Thompson <kst-u@mib.org> - 2016-09-28 12:10 -0700
Re: Is there any place to talk about language features? James Harris <james.harris.1@gmail.com> - 2016-09-28 20:20 +0100
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