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Date: -- (:)
From: Gerd Stolpmann <info@g...>
Subject: [Caml-list] Re: Common IO structure
On Mon, 2004-04-26 at 16:53, Yamagata Yoriyuki wrote:
> From: Gerd Stolpmann <info@gerd-stolpmann.de>
> Subject: Re: Common IO structure (was Re: [Caml-list] [ANN] The Missing Library)
> Date: Sun, 25 Apr 2004 13:54:01 +0200
> 
> > They differ, however, in
> > what they see as their atoms, i.e. smallest entities read from and
> > written to a channel, for ocamlnet atoms are strings, for camomile atoms
> > are characters (char or UChar.t), reflecting a different view what the
> > libraries regard as important features.
> > 
> > I could imagine ocamlnet and camomile share the same signatures if
> > camomile would use some kind of polymorphic strings instead.
> > String-based I/O is much faster than character-based I/O, so camomile
> > would even profit from this change. However, this unification requires
> > that we define the algebraic properties of strings and string buffers,
> > which is not as easy as it sounds.
> 
> When I did a compatison, the speed of Camomile code converter is in
> the same order of iconv (EUC-JP -> UTF8 2-times slower, UTF8 -> EUC-JP
> 50% faster).  I doubt that char-based I/O is significantly slower,
> unless operation is very simple.  String-based I/O has to manage
> buffer strings, which causes extra cost, and anyways the major cost
> comes from elsewhere.  (For code converters, the major cost is caused
> by table lookup.)

I really believe this, when you are doing charset conversions. Note that
ocamlnet's channels are used for other things, too, e.g. email parsing,
and char-by-char operation is simply inacceptable for that.

So I fear one cannot generally say that char-by-char I/O is the common
case.

> That said, I plan to add string-based I/O for character channels,
> partially to interpolate C fucitons.  So, for character channels,
> Camomile would be compatible ocamlnet.

Good news.

Gerd
-- 
------------------------------------------------------------
Gerd Stolpmann * Viktoriastr. 45 * 64293 Darmstadt * Germany 
gerd@gerd-stolpmann.de          http://www.gerd-stolpmann.de
------------------------------------------------------------

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