From: Ludovic Brenta <ludovic@ludovic-brenta.org>
Subject: Re: S-expression I/O in Ada
Date: Thu, 12 Aug 2010 09:19:42 -0700 (PDT)
Date: 2010-08-12T09:19:42-07:00 [thread overview]
Message-ID: <8e7cb956-6d25-46c2-a855-a48673b4ee5e@5g2000yqz.googlegroups.com> (raw)
In-Reply-To: 7990e251-0a92-4790-a24e-0c1899e9295c@a36g2000yqc.googlegroups.com
Natacha Kerensikova wrote on comp.lang.ada:
>> The reason why I prefer to expose the S-Expression is because, in the
>> general (arbitrarily complex) case, you cannot traverse an S-
>> Expresssion linearly; you need to traverse it as what it really is, a
>> tree. A stream suggests linear traversal only.
>
> Yes, linear traversal only is indeed a limitation of Sexp_Stream.
> That's the reason why I had in mind another package of object and
> memory handling, which would rely on Sexp_Stream for the parsing.
>
> I prefer (for now) the Sexp_Stream/memory-object split because 1. it
> makes thing more modular, which means more possibilities of localized
> changes and of implementation overhaul without changing specification,
> and 2. in my real-life application the linear traversal is often
> enough. Far from always though, especially when one counts cases when
> application can traverse linearly but when of the subobjects needs to
> store its sub-S-expression in memory.
OK, let's assume this can work technically. Let's do a cost-benefit
analysis of your preferred solution.
Cost: you limit the use of the S-Expression parser to linear traversal
only; this makes it unsuitable for a general-purpose library, which I
thought was one of your goals.
Cost: while the S-Expression parser has to construct S-Expressions in
memory anyway, you need artificial measures to hide the tree structure
from clients, thereby cluttering the implementation of the S-
Expression parser and making any future changes more difficult.
Benefit: in memory-constrained systems, you may deallocate memory soon
(after the client calls Move_Up, e.g.) and allocate it late (only when
the client calls Get_Atom or Move_Down), thereby holding only one node
at a time in memory. But if you're planning to write a web server, I
don't think you were concerned about the ~100 bytes necessary for the
tree of "(tcp-connect (host foo.bar) (port 80))", were you?
Benefit: I can't see any for the client, honestly, since parsing your
stream is not easier than parsing the S-Expression tree directly, as
you can see when comparing our respective implementations of
TCP_Info.Read.
So, I do think the more general solution is better.
--
Ludovic Brenta.
next prev parent reply other threads:[~2010-08-12 16:19 UTC|newest]
Thread overview: 252+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-01 12:17 S-expression I/O in Ada Natacha Kerensikova
2010-08-01 12:53 ` Dmitry A. Kazakov
2010-08-01 17:35 ` Natacha Kerensikova
2010-08-01 18:49 ` Dmitry A. Kazakov
2010-08-01 20:06 ` Natacha Kerensikova
2010-08-01 21:13 ` Dmitry A. Kazakov
2010-08-02 7:17 ` Georg Bauhaus
2010-08-02 7:58 ` Dmitry A. Kazakov
2010-08-07 7:23 ` Natacha Kerensikova
2010-08-07 8:39 ` Dmitry A. Kazakov
2010-08-07 12:56 ` Natacha Kerensikova
2010-08-07 14:23 ` Dmitry A. Kazakov
2010-08-08 12:23 ` Natacha Kerensikova
2010-08-08 13:01 ` Dmitry A. Kazakov
2010-08-08 13:49 ` Natacha Kerensikova
2010-08-08 15:15 ` Dmitry A. Kazakov
2010-08-09 9:55 ` Natacha Kerensikova
2010-08-09 10:56 ` Dmitry A. Kazakov
2010-08-10 8:56 ` Natacha Kerensikova
2010-08-10 10:17 ` Georg Bauhaus
2010-08-10 10:36 ` Dmitry A. Kazakov
2010-08-10 12:06 ` Natacha Kerensikova
2010-08-10 15:46 ` Dmitry A. Kazakov
2010-08-10 21:22 ` Simon Wright
2010-08-11 7:37 ` Dmitry A. Kazakov
2010-08-11 17:32 ` Simon Wright
2010-08-11 17:53 ` Dmitry A. Kazakov
2010-08-11 9:43 ` Natacha Kerensikova
2010-08-11 10:37 ` Dmitry A. Kazakov
2010-08-11 11:38 ` Natacha Kerensikova
2010-08-11 12:58 ` Robert A Duff
2010-08-11 15:30 ` Natacha Kerensikova
2010-08-11 23:39 ` Randy Brukardt
2010-08-12 1:31 ` Robert A Duff
2010-08-12 8:53 ` Natacha Porté
2010-08-12 9:22 ` Georg Bauhaus
2010-08-13 9:43 ` Natacha Kerensikova
2010-08-10 21:56 ` Randy Brukardt
2010-08-09 15:40 ` Simon Wright
2010-08-09 16:35 ` Robert A Duff
2010-08-10 0:51 ` Randy Brukardt
2010-08-10 1:00 ` Jeffrey Carter
2010-08-10 21:36 ` Randy Brukardt
2010-08-10 22:24 ` Jeffrey Carter
2010-08-10 12:50 ` Robert A Duff
2010-08-10 22:06 ` Randy Brukardt
2010-08-09 18:37 ` Natacha Kerensikova
2010-08-09 19:10 ` Robert A Duff
2010-08-08 14:08 ` Duke Normandin
2010-08-08 15:34 ` Robert A Duff
2010-08-08 18:24 ` Dmitry A. Kazakov
2010-08-08 20:03 ` Robert A Duff
2010-08-08 20:39 ` Dmitry A. Kazakov
2010-08-08 21:08 ` Robert A Duff
2010-08-09 6:50 ` Dmitry A. Kazakov
2010-08-09 13:48 ` Robert A Duff
2010-08-09 14:38 ` Dmitry A. Kazakov
2010-08-09 15:14 ` Georg Bauhaus
2010-08-09 16:11 ` Dmitry A. Kazakov
2010-08-09 16:46 ` Georg Bauhaus
2010-08-09 17:05 ` Robert A Duff
2010-08-09 18:29 ` Georg Bauhaus
2010-08-09 19:18 ` Robert A Duff
2010-08-10 8:21 ` Georg Bauhaus
2010-08-09 20:40 ` Dmitry A. Kazakov
2010-08-09 22:21 ` Georg Bauhaus
2010-08-10 7:07 ` Dmitry A. Kazakov
2010-08-09 16:47 ` Robert A Duff
2010-08-09 19:59 ` Dmitry A. Kazakov
2010-08-09 21:34 ` Robert A Duff
2010-08-09 22:29 ` Jeffrey Carter
2010-08-10 7:48 ` Dmitry A. Kazakov
2010-08-09 21:54 ` _FrnchFrgg_
2010-08-09 22:32 ` Georg Bauhaus
2010-08-10 7:16 ` Dmitry A. Kazakov
2010-08-10 11:06 ` _FrnchFrgg_
2010-08-10 11:19 ` Dmitry A. Kazakov
2010-08-10 23:04 ` _FrnchFrgg_
2010-08-11 14:10 ` Dmitry A. Kazakov
2010-08-11 17:51 ` Structural unification (pattern matching) in Ada [was: Re: S-expression I/O in Ada] _FrnchFrgg_
2010-08-11 18:06 ` Dmitry A. Kazakov
2010-08-11 19:43 ` Robert A Duff
2010-08-11 20:26 ` (see below)
2010-08-11 21:21 ` Structural unification (pattern matching) in Ada Simon Wright
2010-08-12 12:43 ` Structural unification (pattern matching) in Ada [was: Re: S-expression I/O in Ada] _FrnchFrgg_
2010-08-10 1:06 ` S-expression I/O in Ada Randy Brukardt
2010-08-09 16:50 ` Robert A Duff
2010-08-09 18:32 ` Natacha Kerensikova
2010-08-09 19:06 ` Jeffrey Carter
2010-08-09 19:24 ` Robert A Duff
2010-08-09 19:35 ` (see below)
2010-08-09 17:00 ` Robert A Duff
2010-08-09 20:27 ` Dmitry A. Kazakov
2010-08-09 21:30 ` Robert A Duff
2010-08-10 1:17 ` Randy Brukardt
2010-08-10 6:48 ` Dmitry A. Kazakov
2010-08-10 21:42 ` Randy Brukardt
2010-08-11 8:02 ` Dmitry A. Kazakov
2010-08-11 23:18 ` Randy Brukardt
2010-08-12 6:20 ` Dmitry A. Kazakov
2010-08-12 20:56 ` Randy Brukardt
2010-08-13 6:56 ` Dmitry A. Kazakov
2010-08-14 0:52 ` Randy Brukardt
2010-08-09 18:55 ` Jeffrey Carter
2010-08-09 18:20 ` Natacha Kerensikova
2010-08-09 19:19 ` Robert A Duff
2010-08-07 15:38 ` Jeffrey Carter
2010-08-07 17:01 ` Natacha Kerensikova
2010-08-08 6:52 ` Jeffrey Carter
2010-08-08 13:11 ` Natacha Kerensikova
2010-08-08 15:24 ` Robert A Duff
2010-08-09 18:00 ` Natacha Kerensikova
2010-08-09 18:09 ` Robert A Duff
2010-08-08 20:34 ` Jeffrey Carter
2010-08-09 18:10 ` Natacha Kerensikova
2010-08-08 10:26 ` Simon Wright
2010-08-08 11:44 ` Dmitry A. Kazakov
2010-08-08 11:48 ` Dmitry A. Kazakov
2010-08-08 14:05 ` Natacha Kerensikova
2010-08-08 20:11 ` Jeffrey Carter
2010-08-14 1:02 ` Yannick Duchêne (Hibou57)
2010-08-14 9:53 ` Georg Bauhaus
2010-08-14 11:32 ` Natacha Kerensikova
2010-08-01 22:03 ` Simon Wright
2010-08-02 17:08 ` Pascal Obry
2010-08-02 19:08 ` Simon Wright
2010-08-01 16:01 ` Ludovic Brenta
2010-08-09 18:49 ` Ludovic Brenta
2010-08-09 19:59 ` Natacha Kerensikova
2010-08-10 0:11 ` Ludovic Brenta
2010-08-10 0:57 ` Jeffrey Carter
2010-08-10 6:47 ` Natacha Kerensikova
2010-08-10 18:13 ` Jeffrey Carter
2010-08-12 9:26 ` Natacha Kerensikova
2010-08-12 10:55 ` Ludovic Brenta
2010-08-12 12:16 ` Natacha Kerensikova
2010-08-12 12:46 ` Ludovic Brenta
2010-08-12 13:23 ` Natacha Kerensikova
2010-08-12 16:19 ` Ludovic Brenta [this message]
2010-08-12 17:17 ` Natacha Kerensikova
2010-08-12 18:51 ` Jeffrey Carter
2010-08-13 9:32 ` Natacha Kerensikova
2010-08-13 15:52 ` Ludovic Brenta
2010-08-13 22:53 ` Jeffrey R. Carter
2010-08-14 11:10 ` Natacha Kerensikova
2010-08-10 15:48 ` Ludovic Brenta
2010-08-10 15:59 ` Georg Bauhaus
2010-08-12 7:53 ` Ludovic Brenta
2010-08-12 18:55 ` Jeffrey Carter
2010-08-12 19:59 ` Ludovic Brenta
2010-08-12 20:23 ` Natacha Kerensikova
2010-08-12 20:45 ` Ludovic Brenta
2010-08-13 8:24 ` Natacha Kerensikova
2010-08-13 9:08 ` Ludovic Brenta
2010-08-14 10:27 ` Natacha Kerensikova
2010-08-14 11:11 ` Ludovic Brenta
2010-08-14 12:17 ` Natasha Kerensikova
2010-08-14 13:13 ` Ludovic Brenta
2010-08-14 13:33 ` Yannick Duchêne (Hibou57)
2010-08-12 22:25 ` Jeffrey R. Carter
2010-08-13 9:10 ` Natacha Kerensikova
2010-08-13 9:51 ` Dmitry A. Kazakov
2010-08-14 10:36 ` Natacha Kerensikova
2010-08-14 10:57 ` Dmitry A. Kazakov
2010-08-13 19:23 ` Jeffrey Carter
2010-08-13 19:42 ` Dmitry A. Kazakov
2010-08-13 20:44 ` Yannick Duchêne (Hibou57)
2010-08-14 0:57 ` Randy Brukardt
2010-08-14 10:47 ` Natacha Kerensikova
2010-08-13 19:36 ` Simon Wright
2010-08-12 20:11 ` Natacha Kerensikova
2010-08-12 20:22 ` Ludovic Brenta
2010-08-01 18:25 ` Jeffrey Carter
2010-08-01 19:43 ` Natacha Kerensikova
2010-08-01 19:53 ` Ludovic Brenta
2010-08-01 20:00 ` Dmitry A. Kazakov
2010-08-01 20:03 ` Jeffrey Carter
2010-08-01 20:34 ` Georg Bauhaus
2010-08-01 20:44 ` Georg Bauhaus
2010-08-01 21:01 ` anon
2010-08-12 23:26 ` Shark8
2010-08-13 2:31 ` Shark8
2010-08-13 8:56 ` Natacha Kerensikova
2010-08-13 10:30 ` Georg Bauhaus
2010-08-13 15:58 ` Shark8
2010-08-13 21:48 ` Shark8
2010-08-14 11:02 ` Natacha Kerensikova
2010-08-17 17:01 ` Natasha Kerensikova
2010-08-17 19:00 ` Jeffrey Carter
2010-08-18 10:49 ` Natasha Kerensikova
2010-08-18 11:14 ` Ludovic Brenta
2010-08-18 11:59 ` Natasha Kerensikova
2010-08-18 12:31 ` Ludovic Brenta
2010-08-18 13:16 ` J-P. Rosen
2010-08-18 13:55 ` Natasha Kerensikova
2010-08-18 14:40 ` J-P. Rosen
2010-08-20 20:50 ` Yannick Duchêne (Hibou57)
2010-08-18 15:07 ` Ludovic Brenta
2010-08-19 7:42 ` Natasha Kerensikova
2010-08-18 12:51 ` Georg Bauhaus
2010-08-18 13:24 ` Natasha Kerensikova
2010-08-18 14:40 ` Georg Bauhaus
2010-08-18 23:50 ` Randy Brukardt
2010-08-18 11:22 ` Georg Bauhaus
2010-08-18 12:02 ` Natasha Kerensikova
2010-08-20 21:04 ` Yannick Duchêne (Hibou57)
2010-08-22 10:21 ` Natasha Kerensikova
2010-08-22 10:28 ` Simon Wright
2010-08-22 17:13 ` Jeffrey Carter
2010-08-22 14:06 ` Dmitry A. Kazakov
2010-08-21 19:36 ` Yannick Duchêne (Hibou57)
2010-08-18 18:08 ` Jeffrey Carter
2010-08-19 8:09 ` Natasha Kerensikova
2010-08-19 10:16 ` Natasha Kerensikova
2010-08-19 10:42 ` Dmitry A. Kazakov
2010-08-22 10:24 ` Natasha Kerensikova
2010-08-22 14:10 ` Dmitry A. Kazakov
2010-08-19 18:07 ` Jeffrey Carter
2010-08-22 10:43 ` Natasha Kerensikova
2010-08-22 17:17 ` Jeffrey Carter
2010-08-19 17:59 ` Jeffrey Carter
2010-08-22 10:45 ` Natasha Kerensikova
2010-08-22 17:20 ` Jeffrey Carter
2010-08-24 11:41 ` Natasha Kerensikova
2010-08-25 1:56 ` Jeffrey Carter
2010-08-25 12:18 ` Natasha Kerensikova
2010-08-25 14:07 ` Jeffrey Carter
2010-08-25 8:06 ` Georg Bauhaus
2010-08-25 13:27 ` Natasha Kerensikova
2010-08-25 18:55 ` Simon Wright
2010-08-25 19:19 ` Georg Bauhaus
2010-08-25 19:23 ` Georg Bauhaus
2010-08-25 22:38 ` Simon Wright
2010-08-25 23:55 ` Georg Bauhaus
2010-08-27 13:19 ` Natasha Kerensikova
2010-08-27 14:57 ` Georg Bauhaus
2010-08-29 10:45 ` Natasha Kerensikova
2010-08-29 13:10 ` Simon Wright
2010-08-29 14:21 ` Natasha Kerensikova
2010-08-29 14:30 ` Niklas Holsti
2010-08-29 13:23 ` Robert A Duff
2010-08-29 13:57 ` Jeffrey Carter
2010-08-29 14:18 ` Britt Snodgrass
2010-08-29 14:29 ` Natasha Kerensikova
2010-08-29 15:12 ` Robert A Duff
2010-09-03 21:52 ` Randy Brukardt
2010-08-29 13:56 ` Jeffrey Carter
2010-08-29 14:34 ` Natasha Kerensikova
2010-08-29 14:55 ` Dmitry A. Kazakov
2010-08-29 15:25 ` Robert A Duff
2010-08-29 18:50 ` Georg Bauhaus
2010-08-29 21:43 ` Simon Wright
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