[Haskell-cafe] Writing binary files?

Simon Marlow simonmar at microsoft.com
Wed Sep 15 10:06:26 EDT 2004

On 15 September 2004 12:32, ross at soi.city.ac.uk wrote:

> On Mon, Sep 13, 2004 at 12:01:58PM +0100, Glynn Clements wrote:
>> My view is that, right now, we have the worst of both worlds, and
>> taking a short step backwards (i.e. narrow the Char type and leave
>> the rest alone) is a lot simpler (and more feasible) than the long
>> journey towards real I18N.
> This being Haskell, I can't imagine a consensus on a step backwards.
> In any case, a Char type distinct from bytes and the rest is the most
> valuable part of the current situation.  The rest is just libraries,
> and the solution to that is to create other libraries.  (It's true
> that the Prelude is harder to work around, but even that can be done,
> as with the new exception interface.)  Indeed more than one approach
> can proceed concurrently, and that's probably what's going to happen:
>         The Right Thing proceeds in stages:
>         1. new byte-based libraries
>         2. conversions sitting on top of these
>         3. the ultimate I18N API
>         The Quick Fix: alter the existing implementation to use the
>         encoding determined by the current locale at the borders.

I wish I had some more time to work on this, but I implemented a
prototype of an "ultimate" i18n API recently.  This is derived from the
API that Ben Rudiak-Gould proposed last year.

It is in two layers: the InputStream/OutputStream classes provide raw
byte I/O, and the TextStream class provides a conversion on top of that.
The prototype uses iconv for conversions.  You can make Streams from all
sorts of things: files, sockets, pipes, and even Haskell arrays.
InputStream and OutputStreams are just classes, so you can implement
your own.

IIRC, I managed to get it working with speed comparable to GHC's current
IO library.

Here's a tarball that works with GHC 6.2.1 on a Unix platform, just
--make to build it:


If anyone would like to pick this up and run with it, I'd be delighted.
I'm not likely to get back to in the short term, at least.


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