> >> If we keep MK's wcwidth.c in its vanilla state, we can swap in an
> >> update or replacement if it is ever needed without much fuss.
> >
> > Agree.
>
> Me, too. Maybe #include it, or at least copy it in fl_wcwidth.c(xx)
> and leave it as its own function (if possible).
Actually, I'm not sure MK's code will really fly as-is on win32 hosts...
He uses wchar_t as his passed parameter type, but it is apparent from
the way that he uses it that he assumes this is at least a 32-bit type.
E.g. at or near line 202 / 203 of wcwidth.c he compares it to 0x2fffd
and other values larger than 16-bits...
However, on win32 systems, wchar_t is only a 16-bit type, and this part
of the code will not work.
I don't have a Mac or Unix box to hand, but I assume most have a 32-bit
wchar_t (e.g. I assume they are using some UCS-4 (or UTF-32) type
encoding...)
> > Yes - that might be the smart thing to do: then (for example) if we
> > decide to use platform specific functions at a later date,
> all that will
> > be hidden inside fl_wcwidth() or whatever... This function could of
> > course handle the "errors to cp1252" mapping and so forth too, if
> > required.
>
> +1: yes, please, I like fl_wcwidth()
Problems with mk_wcwidth aside, here's a possible implementation then:
--------------------------------------------------------
/* include Markus Kuhn's wcidth.c here. I guess that ideally we'd want
* to inline these functions, as they may get called frequently! */
#include "wcwidth.c"
/* According to information on Microsoft's and the Unicode Consortium's
* websites, positions 0x81, 0x8D, 0x8F, 0x90, and 0x9D are unused.
* However it appears that in practice the Windows API call to convert
* from the CP1252 to Unicode maps these to the corresponding C1
* control codes. */
/* Note: ERRORS_TO_CP1252 is currently defined local to fl_utf.c only,
* so would need to be made "more public" e.g. in config.h or similar */
#ifdef ERRORS_TO_CP1252
/* Map the CP1252 chars to their respective widths. The only valid
values
* here are +1 (for a printable glyph) and -1 (for a C1 ctrl char) */
static const int cp1252_width[32] = {
/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF
*/
/* 8x */ 1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, 1,
-1,
/* 9x */ -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, 1, 1
};
#endif
/* we need at least a 32-bit unsigned type for this... */
int fl_wcwidth(unsigned int ucs) {
#ifdef ERRORS_TO_CP1252
if ((ucs >= 0x80) && (ucs < 0xa0))
return cp1252_width[ucs - 0x80];
else
#endif
return mk_wcwidth(ucs); /* ideally we want this inlined */
} /* fl_wcwidth */
/* end of file */
--
Ian
SELEX Galileo Ltd
Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14
3EL
A company registered in England & Wales. Company no. 02426132
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