+++ /dev/null
-/* Iterating through multibyte strings: macros for multi-byte encodings.
- Copyright (C) 2001, 2005, 2007 Free Software Foundation, Inc.
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-/* Written by Bruno Haible <bruno@clisp.org>. */
-
-/* The macros in this file implement forward iteration through a
- multi-byte string, without knowing its length a-priori.
-
- With these macros, an iteration loop that looks like
-
- char *iter;
- for (iter = buf; *iter != '\0'; iter++)
- {
- do_something (*iter);
- }
-
- becomes
-
- mbui_iterator_t iter;
- for (mbui_init (iter, buf); mbui_avail (iter); mbui_advance (iter))
- {
- do_something (mbui_cur_ptr (iter), mb_len (mbui_cur (iter)));
- }
-
- The benefit of these macros over plain use of mbrtowc is:
- - Handling of invalid multibyte sequences is possible without
- making the code more complicated, while still preserving the
- invalid multibyte sequences.
-
- Compared to mbiter.h, the macros here don't need to know the string's
- length a-priori. The downside is that at each step, the look-ahead
- that guards against overrunning the terminating '\0' is more expensive.
- The mbui_* macros are therefore suitable when there is a high probability
- that only the first few multibyte characters need to be inspected.
- Whereas the mbi_* macros are better if usually the iteration runs
- through the entire string.
-
- mbui_iterator_t
- is a type usable for variable declarations.
-
- mbui_init (iter, startptr)
- initializes the iterator, starting at startptr.
-
- mbui_avail (iter)
- returns true if there are more multibyte chracters available before
- the end of string is reached. In this case, mbui_cur (iter) is
- initialized to the next multibyte chracter.
-
- mbui_advance (iter)
- advances the iterator by one multibyte character.
-
- mbui_cur (iter)
- returns the current multibyte character, of type mbchar_t. All the
- macros defined in mbchar.h can be used on it.
-
- mbui_cur_ptr (iter)
- return a pointer to the beginning of the current multibyte character.
-
- mbui_reloc (iter, ptrdiff)
- relocates iterator when the string is moved by ptrdiff bytes.
-
- mbui_copy (&destiter, &srciter)
- copies srciter to destiter.
-
- Here are the function prototypes of the macros.
-
- extern void mbui_init (mbui_iterator_t iter, const char *startptr);
- extern bool mbui_avail (mbui_iterator_t iter);
- extern void mbui_advance (mbui_iterator_t iter);
- extern mbchar_t mbui_cur (mbui_iterator_t iter);
- extern const char * mbui_cur_ptr (mbui_iterator_t iter);
- extern void mbui_reloc (mbui_iterator_t iter, ptrdiff_t ptrdiff);
- extern void mbui_copy (mbui_iterator_t *new, const mbui_iterator_t *old);
- */
-
-#ifndef _MBUITER_H
-#define _MBUITER_H 1
-
-#include <assert.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-
-/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
- <wchar.h>.
- BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
- <wchar.h>. */
-#include <stdio.h>
-#include <time.h>
-#include <wchar.h>
-
-#include "mbchar.h"
-#include "strnlen1.h"
-
-struct mbuiter_multi
-{
- bool in_shift; /* true if next byte may not be interpreted as ASCII */
- mbstate_t state; /* if in_shift: current shift state */
- bool next_done; /* true if mbui_avail has already filled the following */
- struct mbchar cur; /* the current character:
- const char *cur.ptr pointer to current character
- The following are only valid after mbui_avail.
- size_t cur.bytes number of bytes of current character
- bool cur.wc_valid true if wc is a valid wide character
- wchar_t cur.wc if wc_valid: the current character
- */
-};
-
-static inline void
-mbuiter_multi_next (struct mbuiter_multi *iter)
-{
- if (iter->next_done)
- return;
- if (iter->in_shift)
- goto with_shift;
- /* Handle most ASCII characters quickly, without calling mbrtowc(). */
- if (is_basic (*iter->cur.ptr))
- {
- /* These characters are part of the basic character set. ISO C 99
- guarantees that their wide character code is identical to their
- char code. */
- iter->cur.bytes = 1;
- iter->cur.wc = *iter->cur.ptr;
- iter->cur.wc_valid = true;
- }
- else
- {
- assert (mbsinit (&iter->state));
- iter->in_shift = true;
- with_shift:
- iter->cur.bytes = mbrtowc (&iter->cur.wc, iter->cur.ptr,
- strnlen1 (iter->cur.ptr, MB_CUR_MAX),
- &iter->state);
- if (iter->cur.bytes == (size_t) -1)
- {
- /* An invalid multibyte sequence was encountered. */
- iter->cur.bytes = 1;
- iter->cur.wc_valid = false;
- /* Whether to set iter->in_shift = false and reset iter->state
- or not is not very important; the string is bogus anyway. */
- }
- else if (iter->cur.bytes == (size_t) -2)
- {
- /* An incomplete multibyte character at the end. */
- iter->cur.bytes = strlen (iter->cur.ptr);
- iter->cur.wc_valid = false;
- /* Whether to set iter->in_shift = false and reset iter->state
- or not is not important; the string end is reached anyway. */
- }
- else
- {
- if (iter->cur.bytes == 0)
- {
- /* A null wide character was encountered. */
- iter->cur.bytes = 1;
- assert (*iter->cur.ptr == '\0');
- assert (iter->cur.wc == 0);
- }
- iter->cur.wc_valid = true;
-
- /* When in the initial state, we can go back treating ASCII
- characters more quickly. */
- if (mbsinit (&iter->state))
- iter->in_shift = false;
- }
- }
- iter->next_done = true;
-}
-
-static inline void
-mbuiter_multi_reloc (struct mbuiter_multi *iter, ptrdiff_t ptrdiff)
-{
- iter->cur.ptr += ptrdiff;
-}
-
-static inline void
-mbuiter_multi_copy (struct mbuiter_multi *new_iter, const struct mbuiter_multi *old_iter)
-{
- if ((new_iter->in_shift = old_iter->in_shift))
- memcpy (&new_iter->state, &old_iter->state, sizeof (mbstate_t));
- else
- memset (&new_iter->state, 0, sizeof (mbstate_t));
- new_iter->next_done = old_iter->next_done;
- mb_copy (&new_iter->cur, &old_iter->cur);
-}
-
-/* Iteration macros. */
-typedef struct mbuiter_multi mbui_iterator_t;
-#define mbui_init(iter, startptr) \
- ((iter).cur.ptr = (startptr), \
- (iter).in_shift = false, memset (&(iter).state, '\0', sizeof (mbstate_t)), \
- (iter).next_done = false)
-#define mbui_avail(iter) \
- (mbuiter_multi_next (&(iter)), !mb_isnul ((iter).cur))
-#define mbui_advance(iter) \
- ((iter).cur.ptr += (iter).cur.bytes, (iter).next_done = false)
-
-/* Access to the current character. */
-#define mbui_cur(iter) (iter).cur
-#define mbui_cur_ptr(iter) (iter).cur.ptr
-
-/* Relocation. */
-#define mbui_reloc(iter, ptrdiff) mbuiter_multi_reloc (&iter, ptrdiff)
-
-/* Copying an iterator. */
-#define mbui_copy mbuiter_multi_copy
-
-#endif /* _MBUITER_H */
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