regex.c:196
static void
init_syntax_once()
{
   register int c;
   static int done = 0;

   if (done)
     return;

   memset(re_syntax_table, 0, sizeof re_syntax_table);

   for (c=0; c<=0x7f; c++)
     if (isalnum(c)) 
       re_syntax_table[c] = Sword;
   re_syntax_table['_'] = Sword;

   for (c=0x80; c<=0xff; c++)
     if (isalnum(c)) 
       re_syntax_table[c] = Sword2;
   done = 1;
}
