Re: [Ocaml-lib-devel] Future of ExtLib

[Nicolas C. <war...@fr...>]

> > UTF-8 support should be there, and should be driven from the LANG /
> > LC_* / locale.  It's a non-trivial amount of work to get this to work
> > of course.
>
> I could contribute this.  I have working code for Camomile.  But, it
> requires small C code to call ISO-C functions.  What do you think,
> N(i)colas?

That's little troublesome.
Even if we have only one C little file, the installation, compilation --- 
for a lot of different kind of systems --- is troublesome.
Oh ! just's got a good idea.
If we have to add a C part, then what we should do is a C emulator.
How does it works ?
- it's a C program that can resolve and call dynlinked C functions
- it can also manipulate basic C data structures (convert from and to OCaml
data, and also "raw" access , a little like Obj module)
- it can alloc and free some C memory
Then when we need to add some C parts, we just need to write some Caml code
that will use Emu-C, and which will handle the system particularities... at
runtime.

exemple (far from being correct, just give an idea) :

let strstr = EmuC.resolve "libc" "strstr" in
let found = EmuC.call strstr ["my_string";"_s"] in
if found = EmuC.null then
    None
else
    Some (EmuC.alloc_string found)

> Windows (proper) supports all ISO-C functions?  and (for the future
> reference) how about strcol?

I don't know about that. There is strcoll ANSI compatible function. ( and
wcscoll for Unicode strings )

> In addition, I'm thinking of UTF-16 support (for Windows and Java)  A
> major problem is lack of 16-bit interger array in OCaml.  We could use
> a string and do type-cast when it is passed to C functions.  This
> would  involve detecting endianness in installtion time and providing
> some C-macros.
>
> Alternatively, we could use Bigarray, but Bigarray is not efficient.
>
> I'm interested in other people's opinions.

Use (future) EmuC :-)

let block = EmuC.alloc size in
and then EmuC.setw / EmuC.getw to access 16-bits values into block.

Nicolas Cannasse