From: skaller <skaller@users.sourceforge.net>
To: Stephane Glondu <Stephane.Glondu@crans.org>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] How to do this properly with OCaml?
Date: Mon, 25 Jul 2005 07:55:29 +1000 [thread overview]
Message-ID: <1122242129.9027.229.camel@localhost.localdomain> (raw)
In-Reply-To: <200507241408.29014.Stephane.Glondu@crans.org>
[-- Attachment #1: Type: text/plain, Size: 1615 bytes --]
On Sun, 2005-07-24 at 14:08 -0700, Stephane Glondu wrote:
> BTW, I was talking about 'a array option, not 'a option array. You can use
> (mostly of) the implementation of Buffer, hence have the same
> efficiency... I don't understand your point about "efficiency". If you
> think that the Buffer implementation is not efficient, I may agree with
> you, but this is an algorithmic issue, not a typing issue.
Observe the constructor:
let create n =
let n = if n < 1 then 1 else n in
let n = if n > Sys.max_string_length then Sys.max_string_length else n
in
let s = String.create n in
{buffer = s; position = 0; length = n; initial_buffer = s}
creates an *uninitialised* string of length n:
"val create : int -> string
String.create n returns a fresh string of length n. The string initially
contains arbitrary characters."
If you have to initialise the store, it is expensive,
and if you have to provide a dummy value it is hard
to use.
If you used a 'a array option, and
assert (match Some a -> Array.length a > 0 | None -> true)
then you can use the first value of the array as
the dummy value for the rest of the array, and avoid
Obj.magic -- however this is very inefficient, since
the dummy would have to be changed in many places
whenever the first entry in the array changed
(and that isn't just a store -- there is a write-barrier
to think about .. :)
That won't happen in Buffer because you can't modify it,
but it must be allowed in more general variable length
mutable array.
--
John Skaller <skaller at users dot sourceforge dot net>
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]
next prev parent reply other threads:[~2005-07-24 21:55 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-22 14:26 Thomas Fischbacher
2005-07-22 14:52 ` [Caml-list] " Eric Cooper
2005-07-22 15:26 ` [SPAM_PROBABLE] - [Caml-list] How to do this properly with OCaml? - Bayesian Filter detected spam Christophe Dehlinger
2005-07-22 18:58 ` [Caml-list] How to do this properly with OCaml? Stephane Glondu
2005-07-22 15:50 ` Berke Durak
2005-07-22 16:47 ` brogoff
2005-07-22 15:54 ` Michel Quercia
2005-07-23 5:00 ` Michael Alexander Hamburg
2005-07-23 12:34 ` Xavier Leroy
2005-07-23 13:16 ` Berke Durak
2005-07-23 16:36 ` Stephane Glondu
2005-07-23 18:27 ` Berke Durak
2005-07-23 18:50 ` Matthieu Sozeau
2005-07-24 8:35 ` Berke Durak
2005-07-23 19:18 ` Stephane Glondu
2005-07-23 19:35 ` Thomas Fischbacher
2005-07-23 19:50 ` Stephane Glondu
2005-07-23 19:59 ` Thomas Fischbacher
2005-07-23 20:15 ` Brian Hurt
2005-07-23 23:16 ` james woodyatt
2005-07-23 23:27 ` Stephane Glondu
2005-07-23 18:37 ` Michael Alexander Hamburg
2005-07-23 18:52 ` Bardur Arantsson
2005-07-23 21:35 ` [Caml-list] " Michael Alexander Hamburg
2005-07-23 19:19 ` [Caml-list] " Thomas Fischbacher
2005-07-24 7:27 ` [Caml-list] "Just say no!" campaign against Obj [was: How to do this properly with OCaml?] Alex Baretta
2005-07-24 8:02 ` [Caml-list] "Just say no!" campaign against Obj james woodyatt
2005-07-24 17:27 ` Stephane Glondu
2005-07-25 8:43 ` Alex Baretta
2005-07-24 21:37 ` [Caml-list] "Just say no!" campaign against Obj [was: How to do this properly with OCaml?] brogoff
2005-07-25 8:15 ` Alex Baretta
2005-07-25 17:08 ` brogoff
2005-07-25 8:57 ` Alex Baretta
2005-07-24 17:33 ` [Caml-list] How to do this properly with OCaml? skaller
2005-07-24 18:13 ` Stephane Glondu
2005-07-24 18:48 ` skaller
2005-07-24 19:14 ` Stephane Glondu
2005-07-24 20:29 ` skaller
2005-07-24 20:49 ` skaller
2005-07-24 21:08 ` Stephane Glondu
2005-07-24 21:55 ` skaller [this message]
2005-07-24 23:23 ` Stephane Glondu
2005-07-25 0:32 ` skaller
2005-07-25 6:45 ` Stephane Glondu
2005-07-25 11:35 ` skaller
2005-07-26 0:47 ` Brian Hurt
2005-07-26 0:56 ` Jere Sanisalo
2005-07-26 1:10 ` Brian Hurt
2005-07-26 1:34 ` Jere Sanisalo
2005-07-26 9:03 ` Richard Jones
2005-07-27 17:21 ` skaller
2005-07-27 19:44 ` [Caml-list] Games Jon Harrop
2005-07-27 20:35 ` Jere Sanisalo
2005-07-28 0:13 ` Jon Harrop
2005-07-28 1:12 ` Jere Sanisalo
2005-07-28 2:44 ` Jon Harrop
2005-07-28 4:49 ` skaller
2005-07-28 19:48 ` Jon Harrop
2005-07-28 21:32 ` David Thomas
2005-07-28 22:31 ` Jon Harrop
2005-07-29 1:44 ` Michael Walter
2005-07-29 2:32 ` David Thomas
2005-07-29 3:52 ` skaller
2005-07-29 12:57 ` David Thomas
2005-07-28 10:58 ` Gerd Stolpmann
2005-07-28 17:19 ` David Thomas
2005-07-28 19:22 ` Jon Harrop
2005-07-27 21:13 ` [Caml-list] How to do this properly with OCaml? Pal-Kristian Engstad
2005-07-27 22:28 ` skaller
2005-07-28 1:47 ` Michael Walter
2005-07-27 23:17 ` [Caml-list] Games Jon Harrop
2005-07-28 0:03 ` [Caml-list] How to do this properly with OCaml? Paul Snively
2005-07-28 18:26 ` Jonathan Bryant
2005-07-28 23:10 ` Paul Snively
2005-07-27 16:03 ` skaller
2005-07-26 1:01 ` Stephane Glondu
2005-07-26 1:15 ` Brian Hurt
2005-07-27 15:33 ` skaller
2005-07-30 23:24 ` Thomas Fischbacher
2005-07-31 0:06 ` Jon Harrop
2005-07-31 3:10 ` skaller
2005-07-31 2:54 ` skaller
2005-07-26 20:32 ` David Thomas
2005-07-27 15:05 ` skaller
2005-07-27 15:29 ` Jon Harrop
2005-07-27 15:35 ` David Thomas
2005-07-27 20:11 ` skaller
2005-07-28 16:35 ` David Thomas
2005-07-30 23:33 ` Thomas Fischbacher
2005-07-31 0:39 ` james woodyatt
2005-07-27 19:59 ` skaller
2005-07-26 1:22 ` Jon Harrop
2005-07-27 17:23 ` skaller
2005-07-26 1:05 ` Jon Harrop
2005-07-26 1:20 ` Brian Hurt
2005-07-26 1:28 ` Jon Harrop
2005-07-27 17:03 ` skaller
2005-07-27 16:09 ` skaller
2005-07-24 23:26 ` Brian Hurt
2005-07-25 17:21 ` Ken Rose
2005-07-25 19:19 ` skaller
2005-07-26 7:10 ` Alex Baretta
2005-07-23 18:58 ` Thomas Fischbacher
2005-07-26 1:32 Jon Harrop
[not found] <200507271635.28931.jon@ffconsultancy.com>
2005-07-27 16:31 ` David Thomas
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=1122242129.9027.229.camel@localhost.localdomain \
--to=skaller@users.sourceforge.net \
--cc=Stephane.Glondu@crans.org \
--cc=caml-list@yquem.inria.fr \
/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).