Re: Turkish locale bug

Sezai YILMAZ <sezaiy(at)ata(dot)cs(dot)hun(dot)edu(dot)tr> writes:
> You are right. What about this one?

> setlocale(LC_ALL, "C");

> for(i = 0; yytext[i]; i++)
> if (isascii((unsigned char)yytext[i]) &&
> isupper(yytext[i]))
> yytext[i] = tolower(yytext[i]);

> /* This sets locale to default locale which
> user prefer to use */

> setlocale(LC_ALL, "");

This isn't really better than "if (isupper(ch)) ch = ch + ('a' - 'A')".
It still breaks the existing locale-aware handling of identifier case,
which I believe is considered a good thing in all locales except C
and Turkish. Another small problem is that setlocale() is moderately
expensive in most implementations, and we don't want to call it twice
for every identifier scanned.

I am starting to think that the only real solution is a special case
for Turkish users. Perhaps use tolower() normally but have a compile-
time option to use a non-locale-aware method:

#ifdef LOCALE_AWARE_IDENTIFIER_FOLDING
if (isupper(yytext[i]))
yytext[i] = tolower(yytext[i]);
#else
/* this assumes ASCII encoding... */
if (yytext[i] >= 'A' && yytext[i] <= 'Z')
yytext[i] += 'a' - 'A';
#endif

and then document that you have to disable
LOCALE_AWARE_IDENTIFIER_FOLDING to use Turkish locale.

regards, tom lane