Re: wchar_t and XS

Stolen from lucene interface on CPAN.

\o/

On 27/02/12 16:29, Alberto Simões wrote:
> Hello
>
> I really need to make my code work with XS and wchar_t.
> As far as I can tell there is no typemap for that in the core:
>
> xs/NATools.c:733: warning: passing argument 3 of ‘Perl_sv_setpv’ from
> incompatible pointer type
>
> I googled for that, and found a typemap, but I do not understand how
> typemaps work. My typemap looks like:
>
> ------ 8< ----------
>
>
> TYPEMAP
> wchar_t
>
> INPUT
> T_WCHAR
> {
> // Alloc memory for wide char string. This could be a bit more
> // then necessary.
> Newz(0, $var, SvLEN($arg), wchar_t);
>
> U8* src = (U8*) SvPV_nolen($arg);
> wchar_t* dst = (wchar_t*) $var;
>
> if (SvUTF8($arg)) {
> // UTF8 to wide char mapping
> STRLEN len;
> while (*src) {
> *dst++ = utf8_to_uvuni(src, &len);
> src += len;
> }
> } else {
> // char to wide char mapping
> while (*src) {
> *dst++ = (wchar_t) *src++;
> }
> }
> *dst = 0;
> SAVEFREEPV($var);
> }
> ------ 8< -------------
>
> But then, this seems to be a Perl => wchar only. I would need the other
> way around too.
>
> Any help?
>
> Thanks
> Ambs