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Groups > comp.lang.forth > #47737
| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Quotations |
| Date | 2016-06-02 13:54 +0000 |
| Organization | Institut fuer Computersprachen, Technische Universitaet Wien |
| Message-ID | <2016Jun2.155422@mips.complang.tuwien.ac.at> (permalink) |
| References | (4 earlier) <58c4638d-3015-4b2a-bfc1-b7abb368dbd3@googlegroups.com> <2016Jun1.162929@mips.complang.tuwien.ac.at> <nio6hb$fd6$1@gioia.aioe.org> <X4Odnd2-vbnwYtLKnZ2dnUU7-bPNnZ2d@supernews.com> <c75df337-769e-4e18-aa91-28d2bf7b6d8f@googlegroups.com> |
Raimond Dragomir <raimond.dragomir@gmail.com> writes:
>
>> One problem with this approach is the lifetime of the quotations.
>> There's no garbage collection, so we have to put the captured locals
>
>Who said the parent's locals should be captured? Local variables are
>"local" variables. When parent exits, its locals are gone. Simple as that.
So you want Pascal-like behaviour. This brings us back to the
question of usefulness (and efficiency, see below): I have seen one or
two examples where Pascal locals provided something that could not be
achieved without outer locals, and these examples were not production
code. And the victory of C (which does not have nested functions)
over Pascal indicates that access to outer locals with the Pascal
limitation is not a decisive benefit.
OTOH, I have seen lots of nice examples of using full-blown closures
where locals live on after the function where they were defined has
exited. But we probably don't want to go there in Forth because of
garbage-management issues.
Anyway, if we first standardize quotations without access to outer
locals (leaving such accesses ambiguous), systems can provide extended
versions of that with such access, and if programmers find that
useful, it will spread, and when there is common practice, that can be
standardized as well.
>The mechanism is so simple and easy to implement... Did you hear about frame pointers?
And static link chains (or displays), if you want to implement access
to outer locals. Which means additional overhead and implementation
complexity, especially if you want to reduce the overhead for those
cases where the frame pointers etc. are not needed.
- anton
--
M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
New standard: http://www.forth200x.org/forth200x.html
EuroForth 2016: http://www.euroforth.org/ef16/
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Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-05 22:35 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2015-07-05 23:03 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-05 23:21 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2015-07-06 00:00 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-06 00:10 -0700
Re: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-06 09:39 +0100
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-06 05:28 -0700
Re: Quotations franck.bensusan@gmail.com - 2015-07-06 15:02 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-06 22:43 -0700
Re: Quotations Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-07-06 23:06 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-07 01:27 -0700
Re: Quotations Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-07-07 03:40 -0700
Re: Quotations franck.bensusan@gmail.com - 2015-07-07 04:08 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2015-07-10 02:34 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-14 11:30 -0700
Re: Quotations franck.bensusan@gmail.com - 2015-07-16 03:28 -0700
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-16 09:11 -0700
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2015-07-08 12:04 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-28 13:06 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-29 02:22 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-29 10:41 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-05-29 12:38 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-29 23:03 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 00:34 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-05-30 03:04 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 03:41 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-05-30 08:26 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 08:46 -0700
Re: Quotations Cecil Bayona <cbayona@cbayona.com> - 2016-05-30 10:01 -0500
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 08:33 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-05-30 00:44 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 01:03 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-02 22:07 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-06-02 23:11 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-03 05:18 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-03 05:28 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-03 05:56 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-05-30 15:24 +0000
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 11:33 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-01 14:23 +0000
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 11:46 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-01 14:27 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-01 07:53 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 12:43 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-31 13:25 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-05-31 16:57 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-05-31 19:33 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-06-01 03:20 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-06-01 03:15 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-01 14:29 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-01 08:20 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-01 18:59 -0700
Re: Quotations "WJ" <w_a_x_man@yahoo.com> - 2016-06-02 06:05 +0000
Re: Quotations alex@rivadpm.com - 2016-06-09 09:59 -0700
Re: Quotations "WJ" <w_a_x_man@yahoo.com> - 2016-06-09 17:47 +0000
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-06-01 09:12 -0700
Re: Quotations "HAA" <someone@microsoft.com> - 2016-06-02 12:45 +1000
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-02 04:42 -0500
Re: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2016-06-02 05:08 -0700
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-02 06:53 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-02 13:54 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-02 13:09 -0700
Re: Quotations "HAA" <someone@microsoft.com> - 2016-06-04 12:45 +1000
Re: Quotations hughaguilar96@gmail.com - 2016-06-03 20:52 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-04 15:05 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-06 01:41 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-06 13:12 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-06 08:29 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-07 06:06 +0000
Re: Quotations mhx@iae.nl - 2016-06-06 10:51 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-07 06:36 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-07 00:44 -0700
Re: Quotations mhx@iae.nl - 2016-06-07 11:35 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-08 07:14 +0000
Re: Quotations hughaguilar96@gmail.com - 2016-06-09 00:58 -0700
Re: Quotations "WJ" <w_a_x_man@yahoo.com> - 2016-06-09 11:37 +0000
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-07 12:37 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-07 19:03 -0700
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-02 11:12 -0500
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-02 09:42 -0700
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-03 02:53 -0500
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-03 23:00 -0700
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-04 04:37 -0500
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-05 19:12 -0700
Re: Quotations Paul Rubin <no.email@nospam.invalid> - 2016-06-05 21:20 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-06-09 02:55 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-09 19:20 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-06-10 07:00 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-10 10:00 -0700
Re: Quotations franck.bensusan@gmail.com - 2016-06-10 10:56 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-10 17:56 -0700
Re: Quotations Mark Wills <markwills1970@gmail.com> - 2016-06-14 05:18 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-26 16:12 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-06-02 12:41 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-06-02 13:03 -0700
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-02 13:37 +0000
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-08 04:33 -0500
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-08 09:39 +0000
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-08 05:53 -0500
Re: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-06-08 11:30 +0000
Re: Quotations Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-06-08 08:11 -0500
Re: Quotations hughaguilar96@gmail.com - 2016-06-09 01:09 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-30 08:54 -0700
Re: Quotations hughaguilar96@gmail.com - 2016-05-31 12:06 -0700
Re: Quotations humptydumpty <ouatubi@gmail.com> - 2016-05-31 13:41 -0700
Re: Quotations "WJ" <w_a_x_man@yahoo.com> - 2016-05-31 21:09 +0000
Lambdas (closures) "WJ" <w_a_x_man@yahoo.com> - 2016-06-09 17:18 +0000
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