Commit 3ffcda54 authored by Stefan Monnier's avatar Stefan Monnier
Browse files

(PREV_CHAR_BOUNDARY): Make it work from within a char's byte sequence.

(AT_CHAR_BOUNDARY): New macro.
parent 339250d5
......@@ -658,22 +658,34 @@ else
} while (0)
/* If P is after LIMIT, advance P to the previous character boundary.
It assumes that P is already at a character boundary of the sane
mulitbyte form whose beginning address is LIMIT. */
/* If P is after LIMIT, advance P to the previous character boundary. */
#define PREV_CHAR_BOUNDARY(p, limit) \
do { \
if ((p) > (limit)) \
{ \
const unsigned char *p0 = (p); \
const unsigned char *p_limit = max (limit, p0 - MAX_MULTIBYTE_LENGTH);\
do { \
p0--; \
} while (p0 >= limit && ! CHAR_HEAD_P (*p0)); \
(p) = (BYTES_BY_CHAR_HEAD (*p0) == (p) - p0) ? p0 : (p) - 1; \
} while (p0 >= p_limit && ! CHAR_HEAD_P (*p0)); \
/* If BBCH(*p0) > p-p0, it means we were not on a boundary. */ \
(p) = (BYTES_BY_CHAR_HEAD (*p0) >= (p) - p0) ? p0 : (p) - 1; \
} \
} while (0)
#define AT_CHAR_BOUNDARY_P(result, p, limit) \
do { \
if (CHAR_HEAD_P (*(p)) || (p) <= limit) \
/* Optimization for the common case. */ \
(result) = 1; \
else \
{ \
const unsigned char *p_aux = (p)+1; \
PREV_CHAR_BOUNDARY (p_aux, limit); \
(result) = (p_aux == (p)); \
} \
} while (0)
#ifdef emacs
......
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