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From: Natacha Kerensikova <lithiumcat@gmail.com>
Subject: Re: S-expression I/O in Ada
Date: Thu, 12 Aug 2010 02:26:20 -0700 (PDT)
Date: 2010-08-12T02:26:20-07:00	[thread overview]
Message-ID: <318d4041-eb01-4419-ae68-e6f3436c5b66@i31g2000yqm.googlegroups.com> (raw)
In-Reply-To: i3s4rh$a93$1@adenine.netfront.net

On Aug 10, 8:13 pm, Jeffrey Carter
<spam.jrcarter....@spam.not.acm.org> wrote:
> On 08/09/2010 11:47 PM, Natacha Kerensikova wrote:
> I was commenting on your ideas about writing an S-expression to a stream, which
> included operations to open and close a list, and put an atom. I thought this
> was how you expected a client to output an S-expression.

You thought right, except that due to my discussion with Dmitry I
ended up considering the possibility of splitting my first idea into
two different packages.

Sexp_Stream is supposed to perform S-expression I/O over streams,
without ever constructing a S-expression into memory. It is supposed
to do only the encoding and decoding of S-expression format, to expose
its clients only atoms and relations.

A further unnamed yet package would handle the memory representation
of S-expressions, which involve object creation, memory management and
things like that. It would be a client of Sexp_Stream for I/O, so the
parsing would only be done at one place (namely Sexp_Stream). As I
said Ludovic Brenta's code might take this place.

There are situations when a memory representation of S-expressions is
not needed, and the tcp-connect example here seems to be such a case.
That's why I imagined TCP_Info as a client of Sexp_Stream instead of a
client of the second package.

The stuff with operations to put an atom and open and close a list is
indeed how I think a client of Sexp_Stream should behave. And if I
want Sexp_Stream to have no in-memory representation of a S-
expression, I can't imagine another way of specifying it.

However I'm still undecided whether it's a good thing to have a
Sexp_Stream without memory representation, and whether packages like
TCP_Info should be a client of Sexp_Strean or of the in-memory S-
expression package.

> I think the client should just do
>
> S : S_Expression := Some_Initialization;
>
> Put (File => F, Expression => S);

To achieve such an interface, the client has to build an in-memory S-
expression object. In the tcp-connect example, there are eight nodes
(five atoms and three lists). They have to be somehow built, and it
doesn't look like a simple initialization.

The second interface I proposed, with a lot of nested calls, builds
the S-expression object with functions looking like:
function NewList(Contents, Next: S_node_access) return S_node_access;
function AtomFromWhatever(Contents: whatever, Next: S_node_access)
return S_node_access;

However, unless I'm building other higher-level functions, to build 8
nodes I need 8 function calls, exactly like the second example.

That 8-function-call example looks very C-ish to me, and honestly I
don't like it, I prefer the sequence of procedure calls from
Sexp_Stream example, but that's just a personal taste.

The problem is that I don't see how to do it otherwise. Any idea would
be welcome.

For the TCP_info stuff particular case, the only simplification I can
imagine is leveraging the fact that only 2 among the 8 nodes change.
So one could construct a global S-expression skeleton with the 6
constant nodes, and when actually writing data append to the "host"
and "port" atoms the relevant variable atoms. However that means
having a read/write global variable, which is bad for tasking, so one
might prefer a constant 6-node skeleton, duplicated in the declarative
part of the writing procedure, and then appending the variable nodes.
However that appending would probably end up with lines like:
root_sexp.FirstChild.Next.FirstChild.Append(host_node);
root_Sexp.FirstChild.Next.Next.FirstChild.Append(port_node);
which looks very ugly to me.

> Your TCP_Info-handling pkg would convert the record into an S-expression, and
> call a single operation from your S-expression pkg to output the S-expression.

That's the tricky part. At least so tricky that I can't imagine how to
do it properly.

> Your S-expression library would implement the writing of the expression as a
> series of steps.

Indeed, as a series of calls similar to my Sexp_Stream example. I'm
glad to have at least that part right.



Thanks for your comments,
Natacha



  reply	other threads:[~2010-08-12  9:26 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 [this message]
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
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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