From: Richard Jones <rich@annexia.org>
To: Jonathan Roewen <jonathan.roewen@gmail.com>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Making something similar to format[4]
Date: Sun, 26 Jun 2005 16:10:16 +0100 [thread overview]
Message-ID: <20050626151016.GA25445@furbychan.cocan.org> (raw)
In-Reply-To: <ad8cfe7e05062604075c5d4629@mail.gmail.com>
On Sun, Jun 26, 2005 at 11:07:35PM +1200, Jonathan Roewen wrote:
> I'd like to create something that works like the format type for
> format strings with Printf/Scanf. What I want to do is take a
> one-dimensional bigarray, and a format string of all the sizes of the
> fields corresponding to a struct, and return the typed results.
>
> So sizes of 1 = bool, <= 8 char/int (format specifier to choose char),
> <= 31 int/int32, = 32 int32, > 32, int64.
The OCaml printf/scanf functions are basically hacks done in the
compiler. Whereas it is possible to write a new function which takes
precisely the same string format as printf/scanf, it's not possible to
modify the format without changing the compiler. However, see below ...
> The idea is to make reading/writing C-like structs painless &
> automated. I'm just not sure where to begin in making this type-safe
> format string. Does it require modding the ocaml parser & libraries?
> Cause I'm really confused how ocaml can statically parse the string
> and enforce type safety without some hack in the compiler at some
> stage.
It's actually a really good idea.
I can't see any immediate reason why it couldn't be done trivially
with camlp4. For a good start, read Martin Jambon's camlp4 tutorial
(http://martin.jambon.free.fr/extend-ocaml-syntax.html) and then have
a look at the code for tywith
(http://www.seedwiki.com/wiki/shifting_focus/tywith) and my old
simplesoap library (http://merjis.com/developers/simplesoap) which
both manipulate types from camlp4.
Rich.
--
Richard Jones, CTO Merjis Ltd.
Merjis - web marketing and technology - http://merjis.com
Team Notepad - intranets and extranets for business - http://team-notepad.com
prev parent reply other threads:[~2005-06-26 15:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-26 11:07 Jonathan Roewen
2005-06-26 15:10 ` Richard Jones [this message]
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20050626151016.GA25445@furbychan.cocan.org \
--to=rich@annexia.org \
--cc=caml-list@yquem.inria.fr \
--cc=jonathan.roewen@gmail.com \
/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 NNTP newsgroup(s).