137 lines
3.8 KiB
C
137 lines
3.8 KiB
C
/* Internal header for proving correct grouping in strings of numbers.
|
|
Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
|
|
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <limits.h>
|
|
|
|
#ifndef MAX
|
|
#define MAX(a,b) ({ typeof(a) _a = (a); typeof(b) _b = (b); \
|
|
_a > _b ? _a : _b; })
|
|
#endif
|
|
|
|
/* Find the maximum prefix of the string between BEGIN and END which
|
|
satisfies the grouping rules. It is assumed that at least one digit
|
|
follows BEGIN directly. */
|
|
|
|
static inline const STRING_TYPE *
|
|
correctly_grouped_prefix (const STRING_TYPE *begin, const STRING_TYPE *end,
|
|
wchar_t thousands, const char *grouping)
|
|
{
|
|
if (grouping == NULL)
|
|
return end;
|
|
|
|
if (*grouping == '\0')
|
|
{
|
|
/* No grouping allowed. Accept all characters up to the first
|
|
thousands separator. */
|
|
while (begin < end && *begin != thousands)
|
|
++begin;
|
|
return begin;
|
|
}
|
|
|
|
while (end > begin)
|
|
{
|
|
const STRING_TYPE *cp = end - 1;
|
|
const char *gp = grouping;
|
|
|
|
/* Check first group. */
|
|
while (cp >= begin && (wchar_t) *cp != thousands)
|
|
--cp;
|
|
|
|
if (end - cp == (int) *gp + 1)
|
|
{
|
|
/* This group matches the specification. */
|
|
|
|
const STRING_TYPE *new_end;
|
|
|
|
if (cp < begin)
|
|
/* There is just one complete group. We are done. */
|
|
return end;
|
|
|
|
/* CP points to a thousands separator character. The preceding
|
|
remainder of the string from BEGIN to NEW_END is the part we
|
|
will consider if there is a grouping error in this trailing
|
|
portion from CP to END. */
|
|
new_end = cp - 1;
|
|
|
|
/* Loop while the grouping is correct. */
|
|
while (1)
|
|
{
|
|
/* Get the next grouping rule. */
|
|
++gp;
|
|
if (*gp == 0)
|
|
/* If end is reached use last rule. */
|
|
--gp;
|
|
|
|
/* Skip the thousands separator. */
|
|
--cp;
|
|
|
|
if (*gp == CHAR_MAX
|
|
#if CHAR_MIN < 0
|
|
|| *gp < 0
|
|
#endif
|
|
)
|
|
{
|
|
/* No more thousands separators are allowed to follow. */
|
|
while (cp >= begin && (wchar_t) *cp != thousands)
|
|
--cp;
|
|
|
|
if (cp < begin)
|
|
/* OK, only digits followed. */
|
|
return end;
|
|
}
|
|
else
|
|
{
|
|
/* Check the next group. */
|
|
const STRING_TYPE *group_end = cp;
|
|
|
|
while (cp >= begin && (wchar_t) *cp != thousands)
|
|
--cp;
|
|
|
|
if (cp < begin && group_end - cp <= (int) *gp)
|
|
/* Final group is correct. */
|
|
return end;
|
|
|
|
if (cp < begin || group_end - cp != (int) *gp)
|
|
/* Incorrect group. Punt. */
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* The trailing portion of the string starting at NEW_END
|
|
contains a grouping error. So we will look for a correctly
|
|
grouped number in the preceding portion instead. */
|
|
end = new_end;
|
|
}
|
|
else
|
|
{
|
|
/* Even the first group was wrong; determine maximum shift. */
|
|
if (end - cp > (int) *gp + 1)
|
|
end = cp + (int) *gp + 1;
|
|
else if (cp < begin)
|
|
/* This number does not fill the first group, but is correct. */
|
|
return end;
|
|
else
|
|
/* CP points to a thousands separator character. */
|
|
end = cp;
|
|
}
|
|
}
|
|
|
|
return MAX (begin, end);
|
|
}
|