| /* Internal header for proving correct grouping in strings of numbers. |
| Copyright (C) 1995-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <limits.h> |
| #include <stddef.h> |
| #include <string.h> |
| |
| #ifndef MAX |
| #define MAX(a,b) ({ typeof(a) _a = (a); typeof(b) _b = (b); \ |
| _a > _b ? _a : _b; }) |
| #endif |
| |
| #ifdef USE_WIDE_CHAR |
| # include <wctype.h> |
| # define L_(Ch) L##Ch |
| # define UCHAR_TYPE wint_t |
| # define STRING_TYPE wchar_t |
| #else |
| # define L_(Ch) Ch |
| # define UCHAR_TYPE unsigned char |
| # define STRING_TYPE char |
| #endif |
| |
| #include "grouping.h" |
| |
| /* 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. */ |
| |
| const STRING_TYPE * |
| #ifdef USE_WIDE_CHAR |
| __correctly_grouped_prefixwc (const STRING_TYPE *begin, const STRING_TYPE *end, |
| wchar_t thousands, |
| #else |
| __correctly_grouped_prefixmb (const STRING_TYPE *begin, const STRING_TYPE *end, |
| const char *thousands, |
| #endif |
| const char *grouping) |
| { |
| #ifndef USE_WIDE_CHAR |
| size_t thousands_len; |
| int cnt; |
| #endif |
| |
| if (grouping == NULL) |
| return end; |
| |
| #ifndef USE_WIDE_CHAR |
| thousands_len = strlen (thousands); |
| #endif |
| |
| while (end > begin) |
| { |
| const STRING_TYPE *cp = end - 1; |
| const char *gp = grouping; |
| |
| /* Check first group. */ |
| while (cp >= begin) |
| { |
| #ifdef USE_WIDE_CHAR |
| if (*cp == thousands) |
| break; |
| #else |
| if (cp[thousands_len - 1] == *thousands) |
| { |
| for (cnt = 1; thousands[cnt] != '\0'; ++cnt) |
| if (thousands[cnt] != cp[thousands_len - 1 - cnt]) |
| break; |
| if (thousands[cnt] == '\0') |
| break; |
| } |
| #endif |
| --cp; |
| } |
| |
| /* We allow the representation to contain no grouping at all even if |
| the locale specifies we can have grouping. */ |
| if (cp < begin) |
| return end; |
| |
| 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) |
| { |
| #ifdef USE_WIDE_CHAR |
| if (*cp == thousands) |
| break; |
| #else |
| for (cnt = 0; thousands[cnt] != '\0'; ++cnt) |
| if (thousands[cnt] != cp[thousands_len - cnt - 1]) |
| break; |
| if (thousands[cnt] == '\0') |
| break; |
| #endif |
| --cp; |
| } |
| |
| if (cp < begin) |
| /* OK, only digits followed. */ |
| return end; |
| } |
| else |
| { |
| /* Check the next group. */ |
| const STRING_TYPE *group_end = cp; |
| |
| while (cp >= begin) |
| { |
| #ifdef USE_WIDE_CHAR |
| if (*cp == thousands) |
| break; |
| #else |
| for (cnt = 0; thousands[cnt] != '\0'; ++cnt) |
| if (thousands[cnt] != cp[thousands_len - cnt - 1]) |
| break; |
| if (thousands[cnt] == '\0') |
| break; |
| #endif |
| --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); |
| } |