From: Oleksandr Gavenko <gavenkoa@gmail.com>
To: help-gnu-emacs@gnu.org
Subject: Re: Look for data serialisation format to implement communication between Emacs and external program.
Date: Mon, 07 Jan 2013 15:35:01 +0200 [thread overview]
Message-ID: <871udxt8u2.fsf@gavenkoa.example.com> (raw)
In-Reply-To: 87k3rqudz6.fsf@zigzag.favinet
On 2013-01-07, Thien-Thi Nguyen wrote:
> () Oleksandr Gavenko <gavenkoa@gmail.com>
> () Sun, 06 Jan 2013 23:44:46 +0200
>
> Another formats like JSON or sexp also look nice but I don't know
> about Emacs support for this formats.
>
> Go with sexp. If you must touch XML, at least dress it up as SXML,
> which, aside from being less ugly, extends interop to include Scheme.
> E.g., sexp + SXML is the approach IXIN uses. Latest announcement:
> <http://lists.gnu.org/archive/html/help-texinfo/2013-01/msg00000.html>.
>
One thing stop me from using sexp - my Python code can be possible used in
another cases where sexp parser can be absent.
> If you absolutely need a binary (non-text) format, then i would next
> recommend bindat.el (info "(elisp) Byte Packing") for the job. Perhaps
> ASN.1 can be layered on top of bindat.el, but that doesn't sound so fun.
> (But what do i know about ASN.1 and/or fun?)
>
Thank for suggestion. I completed simple type-length-value example:
(setq bin-str (unibyte-string ?s 4 ?h ?a ?l ?o))
(setq bin-header '((:type u8) (:len u8) (:val vec (:len))))
(setq bin-data (bindat-unpack bin-header bin-str))
(bindat-pack bin-header bin-data)
But as input come from external process I need manually check for input end
because parsing of incomplete input take error "args-out-of-range".
I don't know how to resolve this issue.
I expect to find a way to get data validation for free (like XSD/RNC for XML).
Also I don't see have can I split data into packets with "bindat" (Emacs send
request and Python send response in a loop without dropping connection while
returned data is valid). As solution - make 10 attempt with 1 sec delay and
then report error - incomplete or invalid packet...
> Lastly, on the other side of the pipe, why not consider Emacs itself, or
> Guile, or something that can ‘read’ a sexp?
--
Best regards!
next prev parent reply other threads:[~2013-01-07 13:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-06 21:44 Look for data serialisation format to implement communication between Emacs and external program Oleksandr Gavenko
2013-01-06 22:46 ` Thien-Thi Nguyen
2013-01-07 13:35 ` Oleksandr Gavenko [this message]
2013-01-08 9:44 ` Thien-Thi Nguyen
2013-01-07 21:57 ` Oleksandr Gavenko
[not found] <mailman.16821.1357508702.855.help-gnu-emacs@gnu.org>
2013-01-07 7:53 ` Helmut Eller
2013-01-07 13:53 ` Oleksandr Gavenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=871udxt8u2.fsf@gavenkoa.example.com \
--to=gavenkoa@gmail.com \
--cc=help-gnu-emacs@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).