Re: wadd_wch() operates on wrong coords for non-spacing chars

[Bill Gray]

On 7/5/23 19:41, Thomas Dickey wrote:
> On Wed, Jul 05, 2023 at 09:51:32PM +0200, Roman Zilka wrote:
> > Hello,
> >
> > according to curs_add_wch(3x) add_wch() adds non-spacing characters to
> > the base character on the current coordinates. Therefore, the
> > following program should print "aáa". It prints "áaa", however.
>
> thanks - I can reproduce this, will investigate

   More simply,  addwstr( L"a\u0301aa");  will emit áaa,  not aáa.  So 
does wprintf( "La\u0301aa").  I noticed this some years back and assumed 
it was supposed to be that way:  the combining character modifies the 
preceding character.  A bit of Web searching suggests that's the way 
it's supposed to work;  to get á,  you emit a and then \u0301,  not 
\u0301 and then a.

   Seen from that angle,  Roman's program is working correctly;

    move(0, 1); add_wch(&ccmod);

   says "add an accent to the character just to the left of (0, 1)." 
However,  I have to admit that the man page description,  I think, 
supports Roman's expected behavior.

   I would find it annoying to use \u0301aaa for curses and a\u0301aa 
for everything else.

   Are there any implementations of curses other than ncurses and 
PDCursesMod that handle combining characters?  (I copied the ncurses 
behavior for PDCursesMod,  so that's not independent support for the 
ncurses behavior.)

-- Bill