-/* Low-level bidirectional buffer-scanning functions for GNU Emacs.
+/* Low-level bidirectional buffer/string-scanning functions for GNU Emacs.
Copyright (C) 2000-2001, 2004-2005, 2009-2011
Free Software Foundation, Inc.
/* Written by Eli Zaretskii <eliz@gnu.org>.
A sequential implementation of the Unicode Bidirectional algorithm,
- as per UAX#9, a part of the Unicode Standard.
+ (UBA) as per UAX#9, a part of the Unicode Standard.
Unlike the reference and most other implementations, this one is
designed to be called once for every character in the buffer or
details about its algorithm that finds the next visual-order
character by resolving their levels on the fly.
- The two other entry points are bidi_paragraph_init and
+ Two other entry points are bidi_paragraph_init and
bidi_mirror_char. The first determines the base direction of a
paragraph, while the second returns the mirrored version of its
argument character.
+ A few auxiliary entry points are used to initialize the bidi
+ iterator for iterating an object (buffer or string), push and pop
+ the bidi iterator state, and save and restore the state of the bidi
+ cache.
+
If you want to understand the code, you will have to read it
together with the relevant portions of UAX#9. The comments include
references to UAX#9 rules, for that very reason.
static Lisp_Object bidi_type_table, bidi_mirror_table;
-/* FIXME: Remove these when bidi_explicit_dir_char uses a lookup table. */
#define LRM_CHAR 0x200E
#define RLM_CHAR 0x200F
-#define LRE_CHAR 0x202A
-#define RLE_CHAR 0x202B
-#define PDF_CHAR 0x202C
-#define LRO_CHAR 0x202D
-#define RLO_CHAR 0x202E
-
#define BIDI_EOB -1
-/* Local data structures. (Look in dispextern.h for the rest.) */
-
-/* What we need to know about the current paragraph. */
-struct bidi_paragraph_info {
- EMACS_INT start_bytepos; /* byte position where it begins */
- EMACS_INT end_bytepos; /* byte position where it ends */
- int embedding_level; /* its basic embedding level */
- bidi_dir_t base_dir; /* its base direction */
-};
-
/* Data type for describing the bidirectional character categories. */
typedef enum {
UNKNOWN_BC,
static Lisp_Object paragraph_start_re, paragraph_separate_re;
static Lisp_Object Qparagraph_start, Qparagraph_separate;
-static void
-bidi_initialize (void)
-{
-
-#include "biditype.h"
-#include "bidimirror.h"
-
- int i;
-
- bidi_type_table = Fmake_char_table (Qnil, make_number (STRONG_L));
- staticpro (&bidi_type_table);
-
- for (i = 0; i < sizeof bidi_type / sizeof bidi_type[0]; i++)
- char_table_set_range (bidi_type_table, bidi_type[i].from, bidi_type[i].to,
- make_number (bidi_type[i].type));
-
- bidi_mirror_table = Fmake_char_table (Qnil, Qnil);
- staticpro (&bidi_mirror_table);
-
- for (i = 0; i < sizeof bidi_mirror / sizeof bidi_mirror[0]; i++)
- char_table_set (bidi_mirror_table, bidi_mirror[i].from,
- make_number (bidi_mirror[i].to));
-
- Qparagraph_start = intern ("paragraph-start");
- staticpro (&Qparagraph_start);
- paragraph_start_re = Fsymbol_value (Qparagraph_start);
- if (!STRINGP (paragraph_start_re))
- paragraph_start_re = build_string ("\f\\|[ \t]*$");
- staticpro (¶graph_start_re);
- Qparagraph_separate = intern ("paragraph-separate");
- staticpro (&Qparagraph_separate);
- paragraph_separate_re = Fsymbol_value (Qparagraph_separate);
- if (!STRINGP (paragraph_separate_re))
- paragraph_separate_re = build_string ("[ \t\f]*$");
- staticpro (¶graph_separate_re);
- bidi_initialized = 1;
-}
+\f
+/***********************************************************************
+ Utilities
+ ***********************************************************************/
/* Return the bidi type of a character CH, subject to the current
directional OVERRIDE. */
-static INLINE bidi_type_t
+static inline bidi_type_t
bidi_get_type (int ch, bidi_dir_t override)
{
bidi_type_t default_type;
}
/* Given a bidi TYPE of a character, return its category. */
-static INLINE bidi_category_t
+static inline bidi_category_t
bidi_get_category (bidi_type_t type)
{
switch (type)
return c;
}
+/* Determine the start-of-run (sor) directional type given the two
+ embedding levels on either side of the run boundary. Also, update
+ the saved info about previously seen characters, since that info is
+ generally valid for a single level run. */
+static inline void
+bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
+{
+ int higher_level = level_before > level_after ? level_before : level_after;
+
+ /* The prev_was_pdf gork is required for when we have several PDFs
+ in a row. In that case, we want to compute the sor type for the
+ next level run only once: when we see the first PDF. That's
+ because the sor type depends only on the higher of the two levels
+ that we find on the two sides of the level boundary (see UAX#9,
+ clause X10), and so we don't need to know the final embedding
+ level to which we descend after processing all the PDFs. */
+ if (!bidi_it->prev_was_pdf || level_before < level_after)
+ /* FIXME: should the default sor direction be user selectable? */
+ bidi_it->sor = (higher_level & 1) != 0 ? R2L : L2R;
+ if (level_before > level_after)
+ bidi_it->prev_was_pdf = 1;
+
+ bidi_it->prev.type = UNKNOWN_BT;
+ bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 =
+ bidi_it->last_strong.orig_type = UNKNOWN_BT;
+ bidi_it->prev_for_neutral.type = bidi_it->sor == R2L ? STRONG_R : STRONG_L;
+ bidi_it->prev_for_neutral.charpos = bidi_it->charpos;
+ bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos;
+ bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.type_after_w1 =
+ bidi_it->next_for_neutral.orig_type = UNKNOWN_BT;
+ bidi_it->ignore_bn_limit = -1; /* meaning it's unknown */
+}
+
+/* Push the current embedding level and override status; reset the
+ current level to LEVEL and the current override status to OVERRIDE. */
+static inline void
+bidi_push_embedding_level (struct bidi_it *bidi_it,
+ int level, bidi_dir_t override)
+{
+ bidi_it->stack_idx++;
+ xassert (bidi_it->stack_idx < BIDI_MAXLEVEL);
+ bidi_it->level_stack[bidi_it->stack_idx].level = level;
+ bidi_it->level_stack[bidi_it->stack_idx].override = override;
+}
+
+/* Pop the embedding level and directional override status from the
+ stack, and return the new level. */
+static inline int
+bidi_pop_embedding_level (struct bidi_it *bidi_it)
+{
+ /* UAX#9 says to ignore invalid PDFs. */
+ if (bidi_it->stack_idx > 0)
+ bidi_it->stack_idx--;
+ return bidi_it->level_stack[bidi_it->stack_idx].level;
+}
+
+/* Record in SAVED_INFO the information about the current character. */
+static inline void
+bidi_remember_char (struct bidi_saved_info *saved_info,
+ struct bidi_it *bidi_it)
+{
+ saved_info->charpos = bidi_it->charpos;
+ saved_info->bytepos = bidi_it->bytepos;
+ saved_info->type = bidi_it->type;
+ bidi_check_type (bidi_it->type);
+ saved_info->type_after_w1 = bidi_it->type_after_w1;
+ bidi_check_type (bidi_it->type_after_w1);
+ saved_info->orig_type = bidi_it->orig_type;
+ bidi_check_type (bidi_it->orig_type);
+}
+
/* Copy the bidi iterator from FROM to TO. To save cycles, this only
copies the part of the level stack that is actually in use. */
-static INLINE void
+static inline void
bidi_copy_it (struct bidi_it *to, struct bidi_it *from)
{
int i;
/* Copy everything except the level stack and beyond. */
- memcpy (to, from, ((size_t)&((struct bidi_it *)0)->level_stack[0]));
+ memcpy (to, from, offsetof (struct bidi_it, level_stack[0]));
/* Copy the active part of the level stack. */
to->level_stack[0] = from->level_stack[0]; /* level zero is always in use */
to->level_stack[i] = from->level_stack[i];
}
-/* Caching the bidi iterator states. */
+\f
+/***********************************************************************
+ Caching the bidi iterator states
+ ***********************************************************************/
#define BIDI_CACHE_CHUNK 200
static struct bidi_it *bidi_cache;
-static size_t bidi_cache_size = 0;
-static size_t elsz = sizeof (struct bidi_it);
-static int bidi_cache_idx; /* next unused cache slot */
-static int bidi_cache_last_idx; /* slot of last cache hit */
-
-static INLINE void
+static EMACS_INT bidi_cache_size = 0;
+enum { elsz = sizeof (struct bidi_it) };
+static EMACS_INT bidi_cache_idx; /* next unused cache slot */
+static EMACS_INT bidi_cache_last_idx; /* slot of last cache hit */
+static EMACS_INT bidi_cache_start = 0; /* start of cache for this
+ "stack" level */
+
+/* Reset the cache state to the empty state. We only reset the part
+ of the cache relevant to iteration of the current object. Previous
+ objects, which are pushed on the display iterator's stack, are left
+ intact. This is called when the cached information is no more
+ useful for the current iteration, e.g. when we were reseated to a
+ new position on the same object. */
+static inline void
bidi_cache_reset (void)
{
- bidi_cache_idx = 0;
+ bidi_cache_idx = bidi_cache_start;
bidi_cache_last_idx = -1;
}
-static INLINE void
+/* Shrink the cache to its minimal size. Called when we init the bidi
+ iterator for reordering a buffer or a string that does not come
+ from display properties, because that means all the previously
+ cached info is of no further use. */
+static inline void
bidi_cache_shrink (void)
{
if (bidi_cache_size > BIDI_CACHE_CHUNK)
bidi_cache_reset ();
}
-static INLINE void
-bidi_cache_fetch_state (int idx, struct bidi_it *bidi_it)
+static inline void
+bidi_cache_fetch_state (EMACS_INT idx, struct bidi_it *bidi_it)
{
int current_scan_dir = bidi_it->scan_dir;
- if (idx < 0 || idx >= bidi_cache_idx)
+ if (idx < bidi_cache_start || idx >= bidi_cache_idx)
abort ();
bidi_copy_it (bidi_it, &bidi_cache[idx]);
level less or equal to LEVEL. if LEVEL is -1, disregard the
resolved levels in cached states. DIR, if non-zero, means search
in that direction from the last cache hit. */
-static INLINE int
+static inline EMACS_INT
bidi_cache_search (EMACS_INT charpos, int level, int dir)
{
- int i, i_start;
+ EMACS_INT i, i_start;
- if (bidi_cache_idx)
+ if (bidi_cache_idx > bidi_cache_start)
{
+ if (bidi_cache_last_idx == -1)
+ bidi_cache_last_idx = bidi_cache_idx - 1;
if (charpos < bidi_cache[bidi_cache_last_idx].charpos)
- dir = -1;
- else if (charpos > bidi_cache[bidi_cache_last_idx].charpos)
- dir = 1;
- if (dir)
+ {
+ dir = -1;
+ i_start = bidi_cache_last_idx - 1;
+ }
+ else if (charpos > (bidi_cache[bidi_cache_last_idx].charpos
+ + bidi_cache[bidi_cache_last_idx].nchars - 1))
+ {
+ dir = 1;
+ i_start = bidi_cache_last_idx + 1;
+ }
+ else if (dir)
i_start = bidi_cache_last_idx;
else
{
if (dir < 0)
{
/* Linear search for now; FIXME! */
- for (i = i_start; i >= 0; i--)
- if (bidi_cache[i].charpos == charpos
+ for (i = i_start; i >= bidi_cache_start; i--)
+ if (bidi_cache[i].charpos <= charpos
+ && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars
&& (level == -1 || bidi_cache[i].resolved_level <= level))
return i;
}
else
{
for (i = i_start; i < bidi_cache_idx; i++)
- if (bidi_cache[i].charpos == charpos
+ if (bidi_cache[i].charpos <= charpos
+ && charpos < bidi_cache[i].charpos + bidi_cache[i].nchars
&& (level == -1 || bidi_cache[i].resolved_level <= level))
return i;
}
/* Find a cached state where the resolved level changes to a value
that is lower than LEVEL, and return its cache slot index. DIR is
the direction to search, starting with the last used cache slot.
- BEFORE, if non-zero, means return the index of the slot that is
- ``before'' the level change in the search direction. That is,
+ If DIR is zero, we search backwards from the last occupied cache
+ slot. BEFORE, if non-zero, means return the index of the slot that
+ is ``before'' the level change in the search direction. That is,
given the cached levels like this:
1122333442211
C, searching backwards (DIR = -1) for LEVEL = 2 will return the
index of slot B or A, depending whether BEFORE is, respectively,
non-zero or zero. */
-static int
+static EMACS_INT
bidi_cache_find_level_change (int level, int dir, int before)
{
if (bidi_cache_idx)
{
- int i = dir ? bidi_cache_last_idx : bidi_cache_idx - 1;
+ EMACS_INT i = dir ? bidi_cache_last_idx : bidi_cache_idx - 1;
int incr = before ? 1 : 0;
+ xassert (!dir || bidi_cache_last_idx >= 0);
+
if (!dir)
dir = -1;
else if (!incr)
if (dir < 0)
{
- while (i >= incr)
+ while (i >= bidi_cache_start + incr)
{
if (bidi_cache[i - incr].resolved_level >= 0
&& bidi_cache[i - incr].resolved_level < level)
return -1;
}
-static INLINE void
+static inline void
+bidi_cache_ensure_space (EMACS_INT idx)
+{
+ /* Enlarge the cache as needed. */
+ if (idx >= bidi_cache_size)
+ {
+ while (idx >= bidi_cache_size)
+ bidi_cache_size += BIDI_CACHE_CHUNK;
+ bidi_cache =
+ (struct bidi_it *) xrealloc (bidi_cache, bidi_cache_size * elsz);
+ }
+}
+
+static inline void
bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
{
- int idx;
+ EMACS_INT idx;
/* We should never cache on backward scans. */
if (bidi_it->scan_dir == -1)
if (idx < 0)
{
idx = bidi_cache_idx;
- /* Enlarge the cache as needed. */
- if (idx >= bidi_cache_size)
- {
- bidi_cache_size += BIDI_CACHE_CHUNK;
- bidi_cache =
- (struct bidi_it *) xrealloc (bidi_cache, bidi_cache_size * elsz);
- }
+ bidi_cache_ensure_space (idx);
/* Character positions should correspond to cache positions 1:1.
If we are outside the range of cached positions, the cache is
useless and must be reset. */
- if (idx > 0 &&
- (bidi_it->charpos > bidi_cache[idx - 1].charpos + 1
- || bidi_it->charpos < bidi_cache[0].charpos))
+ if (idx > bidi_cache_start &&
+ (bidi_it->charpos > (bidi_cache[idx - 1].charpos
+ + bidi_cache[idx - 1].nchars)
+ || bidi_it->charpos < bidi_cache[bidi_cache_start].charpos))
{
bidi_cache_reset ();
- idx = 0;
+ idx = bidi_cache_start;
}
+ if (bidi_it->nchars <= 0)
+ abort ();
bidi_copy_it (&bidi_cache[idx], bidi_it);
if (!resolved)
bidi_cache[idx].resolved_level = -1;
bidi_cache_idx = idx + 1;
}
-static INLINE bidi_type_t
+static inline bidi_type_t
bidi_cache_find (EMACS_INT charpos, int level, struct bidi_it *bidi_it)
{
- int i = bidi_cache_search (charpos, level, bidi_it->scan_dir);
+ EMACS_INT i = bidi_cache_search (charpos, level, bidi_it->scan_dir);
- if (i >= 0)
+ if (i >= bidi_cache_start)
{
bidi_dir_t current_scan_dir = bidi_it->scan_dir;
return UNKNOWN_BT;
}
-static INLINE int
+static inline int
bidi_peek_at_next_level (struct bidi_it *bidi_it)
{
- if (bidi_cache_idx == 0 || bidi_cache_last_idx == -1)
+ if (bidi_cache_idx == bidi_cache_start || bidi_cache_last_idx == -1)
abort ();
return bidi_cache[bidi_cache_last_idx + bidi_it->scan_dir].resolved_level;
}
-/* Check if buffer position CHARPOS/BYTEPOS is the end of a paragraph.
- Value is the non-negative length of the paragraph separator
- following the buffer position, -1 if position is at the beginning
- of a new paragraph, or -2 if position is neither at beginning nor
- at end of a paragraph. */
-static EMACS_INT
-bidi_at_paragraph_end (EMACS_INT charpos, EMACS_INT bytepos)
+\f
+/***********************************************************************
+ Pushing and popping the bidi iterator state
+ ***********************************************************************/
+/* 5-slot stack for saving the start of the previous level of the
+ cache. xdisp.c maintains a 5-slot stack for its iterator state,
+ and we need the same size of our stack. */
+static EMACS_INT bidi_cache_start_stack[IT_STACK_SIZE];
+static int bidi_cache_sp;
+
+/* Push the bidi iterator state in preparation for reordering a
+ different object, e.g. display string found at certain buffer
+ position. Pushing the bidi iterator boils down to saving its
+ entire state on the cache and starting a new cache "stacked" on top
+ of the current cache. */
+void
+bidi_push_it (struct bidi_it *bidi_it)
{
- Lisp_Object sep_re;
- Lisp_Object start_re;
- EMACS_INT val;
+ /* Save the current iterator state in its entirety after the last
+ used cache slot. */
+ bidi_cache_ensure_space (bidi_cache_idx);
+ memcpy (&bidi_cache[bidi_cache_idx++], bidi_it, sizeof (struct bidi_it));
- sep_re = paragraph_separate_re;
- start_re = paragraph_start_re;
+ /* Push the current cache start onto the stack. */
+ xassert (bidi_cache_sp < IT_STACK_SIZE);
+ bidi_cache_start_stack[bidi_cache_sp++] = bidi_cache_start;
- val = fast_looking_at (sep_re, charpos, bytepos, ZV, ZV_BYTE, Qnil);
- if (val < 0)
+ /* Start a new level of cache, and make it empty. */
+ bidi_cache_start = bidi_cache_idx;
+ bidi_cache_last_idx = -1;
+}
+
+/* Restore the iterator state saved by bidi_push_it and return the
+ cache to the corresponding state. */
+void
+bidi_pop_it (struct bidi_it *bidi_it)
+{
+ if (bidi_cache_start <= 0)
+ abort ();
+
+ /* Reset the next free cache slot index to what it was before the
+ call to bidi_push_it. */
+ bidi_cache_idx = bidi_cache_start - 1;
+
+ /* Restore the bidi iterator state saved in the cache. */
+ memcpy (bidi_it, &bidi_cache[bidi_cache_idx], sizeof (struct bidi_it));
+
+ /* Pop the previous cache start from the stack. */
+ if (bidi_cache_sp <= 0)
+ abort ();
+ bidi_cache_start = bidi_cache_start_stack[--bidi_cache_sp];
+
+ /* Invalidate the last-used cache slot data. */
+ bidi_cache_last_idx = -1;
+}
+
+/* Stash away a copy of the cache and its control variables. */
+void *
+bidi_shelve_cache (void)
+{
+ unsigned char *databuf;
+
+ if (bidi_cache_idx == 0)
+ return NULL;
+
+ databuf = xmalloc (sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack)
+ + sizeof (bidi_cache_sp) + sizeof (bidi_cache_start)
+ + sizeof (bidi_cache_last_idx));
+ memcpy (databuf, &bidi_cache_idx, sizeof (bidi_cache_idx));
+ memcpy (databuf + sizeof (bidi_cache_idx),
+ bidi_cache, bidi_cache_idx * sizeof (struct bidi_it));
+ memcpy (databuf + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it),
+ bidi_cache_start_stack, sizeof (bidi_cache_start_stack));
+ memcpy (databuf + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack),
+ &bidi_cache_sp, sizeof (bidi_cache_sp));
+ memcpy (databuf + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp),
+ &bidi_cache_start, sizeof (bidi_cache_start));
+ memcpy (databuf + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
+ + sizeof (bidi_cache_start),
+ &bidi_cache_last_idx, sizeof (bidi_cache_last_idx));
+
+ return databuf;
+}
+
+/* Restore the cache state from a copy stashed away by bidi_shelve_cache. */
+void
+bidi_unshelve_cache (void *databuf)
+{
+ unsigned char *p = databuf;
+
+ if (!p)
{
- if (fast_looking_at (start_re, charpos, bytepos, ZV, ZV_BYTE, Qnil) >= 0)
- val = -1;
- else
- val = -2;
+ /* A NULL pointer means an empty cache. */
+ bidi_cache_start = 0;
+ bidi_cache_sp = 0;
+ bidi_cache_reset ();
+ }
+ else
+ {
+ memcpy (&bidi_cache_idx, p, sizeof (bidi_cache_idx));
+ bidi_cache_ensure_space (bidi_cache_idx);
+ memcpy (bidi_cache, p + sizeof (bidi_cache_idx),
+ bidi_cache_idx * sizeof (struct bidi_it));
+ memcpy (bidi_cache_start_stack,
+ p + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it),
+ sizeof (bidi_cache_start_stack));
+ memcpy (&bidi_cache_sp,
+ p + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack),
+ sizeof (bidi_cache_sp));
+ memcpy (&bidi_cache_start,
+ p + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp),
+ sizeof (bidi_cache_start));
+ memcpy (&bidi_cache_last_idx,
+ p + sizeof (bidi_cache_idx)
+ + bidi_cache_idx * sizeof (struct bidi_it)
+ + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
+ + sizeof (bidi_cache_start),
+ sizeof (bidi_cache_last_idx));
+
+ xfree (p);
}
-
- return val;
}
-/* Determine the start-of-run (sor) directional type given the two
- embedding levels on either side of the run boundary. Also, update
- the saved info about previously seen characters, since that info is
- generally valid for a single level run. */
-static INLINE void
-bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
+\f
+/***********************************************************************
+ Initialization
+ ***********************************************************************/
+static void
+bidi_initialize (void)
{
- int higher_level = level_before > level_after ? level_before : level_after;
- /* The prev_was_pdf gork is required for when we have several PDFs
- in a row. In that case, we want to compute the sor type for the
- next level run only once: when we see the first PDF. That's
- because the sor type depends only on the higher of the two levels
- that we find on the two sides of the level boundary (see UAX#9,
- clause X10), and so we don't need to know the final embedding
- level to which we descend after processing all the PDFs. */
- if (!bidi_it->prev_was_pdf || level_before < level_after)
- /* FIXME: should the default sor direction be user selectable? */
- bidi_it->sor = (higher_level & 1) != 0 ? R2L : L2R;
- if (level_before > level_after)
- bidi_it->prev_was_pdf = 1;
+#include "biditype.h"
+#include "bidimirror.h"
- bidi_it->prev.type = UNKNOWN_BT;
+ int i;
+
+ bidi_type_table = Fmake_char_table (Qnil, make_number (STRONG_L));
+ staticpro (&bidi_type_table);
+
+ for (i = 0; i < sizeof bidi_type / sizeof bidi_type[0]; i++)
+ char_table_set_range (bidi_type_table, bidi_type[i].from, bidi_type[i].to,
+ make_number (bidi_type[i].type));
+
+ bidi_mirror_table = Fmake_char_table (Qnil, Qnil);
+ staticpro (&bidi_mirror_table);
+
+ for (i = 0; i < sizeof bidi_mirror / sizeof bidi_mirror[0]; i++)
+ char_table_set (bidi_mirror_table, bidi_mirror[i].from,
+ make_number (bidi_mirror[i].to));
+
+ Qparagraph_start = intern ("paragraph-start");
+ staticpro (&Qparagraph_start);
+ paragraph_start_re = Fsymbol_value (Qparagraph_start);
+ if (!STRINGP (paragraph_start_re))
+ paragraph_start_re = build_string ("\f\\|[ \t]*$");
+ staticpro (¶graph_start_re);
+ Qparagraph_separate = intern ("paragraph-separate");
+ staticpro (&Qparagraph_separate);
+ paragraph_separate_re = Fsymbol_value (Qparagraph_separate);
+ if (!STRINGP (paragraph_separate_re))
+ paragraph_separate_re = build_string ("[ \t\f]*$");
+ staticpro (¶graph_separate_re);
+
+ bidi_cache_sp = 0;
+
+ bidi_initialized = 1;
+}
+
+/* Do whatever UAX#9 clause X8 says should be done at paragraph's
+ end. */
+static inline void
+bidi_set_paragraph_end (struct bidi_it *bidi_it)
+{
+ bidi_it->invalid_levels = 0;
+ bidi_it->invalid_rl_levels = -1;
+ bidi_it->stack_idx = 0;
+ bidi_it->resolved_level = bidi_it->level_stack[0].level;
+}
+
+/* Initialize the bidi iterator from buffer/string position CHARPOS. */
+void
+bidi_init_it (EMACS_INT charpos, EMACS_INT bytepos, int frame_window_p,
+ struct bidi_it *bidi_it)
+{
+ if (! bidi_initialized)
+ bidi_initialize ();
+ if (charpos >= 0)
+ bidi_it->charpos = charpos;
+ if (bytepos >= 0)
+ bidi_it->bytepos = bytepos;
+ bidi_it->frame_window_p = frame_window_p;
+ bidi_it->nchars = -1; /* to be computed in bidi_resolve_explicit_1 */
+ bidi_it->first_elt = 1;
+ bidi_set_paragraph_end (bidi_it);
+ bidi_it->new_paragraph = 1;
+ bidi_it->separator_limit = -1;
+ bidi_it->type = NEUTRAL_B;
+ bidi_it->type_after_w1 = NEUTRAL_B;
+ bidi_it->orig_type = NEUTRAL_B;
+ bidi_it->prev_was_pdf = 0;
+ bidi_it->prev.type = bidi_it->prev.type_after_w1 =
+ bidi_it->prev.orig_type = UNKNOWN_BT;
bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 =
bidi_it->last_strong.orig_type = UNKNOWN_BT;
- bidi_it->prev_for_neutral.type = bidi_it->sor == R2L ? STRONG_R : STRONG_L;
- bidi_it->prev_for_neutral.charpos = bidi_it->charpos;
- bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos;
- bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.type_after_w1 =
+ bidi_it->next_for_neutral.charpos = -1;
+ bidi_it->next_for_neutral.type =
+ bidi_it->next_for_neutral.type_after_w1 =
bidi_it->next_for_neutral.orig_type = UNKNOWN_BT;
- bidi_it->ignore_bn_limit = 0; /* meaning it's unknown */
+ bidi_it->prev_for_neutral.charpos = -1;
+ bidi_it->prev_for_neutral.type =
+ bidi_it->prev_for_neutral.type_after_w1 =
+ bidi_it->prev_for_neutral.orig_type = UNKNOWN_BT;
+ bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */
+ bidi_it->disp_pos = -1; /* invalid/unknown */
+ /* We can only shrink the cache if we are at the bottom level of its
+ "stack". */
+ if (bidi_cache_start == 0)
+ bidi_cache_shrink ();
+ else
+ bidi_cache_reset ();
}
+/* Perform initializations for reordering a new line of bidi text. */
static void
bidi_line_init (struct bidi_it *bidi_it)
{
bidi_cache_reset ();
}
+\f
+/***********************************************************************
+ Fetching characters
+ ***********************************************************************/
+
+/* Count bytes in string S between BEG/BEGBYTE and END. BEG and END
+ are zero-based character positions in S, BEGBYTE is byte position
+ corresponding to BEG. UNIBYTE, if non-zero, means S is a unibyte
+ string. */
+static inline EMACS_INT
+bidi_count_bytes (const unsigned char *s, const EMACS_INT beg,
+ const EMACS_INT begbyte, const EMACS_INT end, int unibyte)
+{
+ EMACS_INT pos = beg;
+ const unsigned char *p = s + begbyte, *start = p;
+
+ if (unibyte)
+ p = s + end;
+ else
+ {
+ if (!CHAR_HEAD_P (*p))
+ abort ();
+
+ while (pos < end)
+ {
+ p += BYTES_BY_CHAR_HEAD (*p);
+ pos++;
+ }
+ }
+
+ return p - start;
+}
+
+/* Fetch and returns the character at byte position BYTEPOS. If S is
+ non-NULL, fetch the character from string S; otherwise fetch the
+ character from the current buffer. UNIBYTE non-zero means S is a
+ unibyte string. */
+static inline int
+bidi_char_at_pos (EMACS_INT bytepos, const unsigned char *s, int unibyte)
+{
+ if (s)
+ {
+ if (unibyte)
+ return s[bytepos];
+ else
+ return STRING_CHAR (s + bytepos);
+ }
+ else
+ return FETCH_MULTIBYTE_CHAR (bytepos);
+}
+
+/* Fetch and return the character at BYTEPOS/CHARPOS. If that
+ character is covered by a display string, treat the entire run of
+ covered characters as a single character u+FFFC, and return their
+ combined length in CH_LEN and NCHARS. DISP_POS specifies the
+ character position of the next display string, or -1 if not yet
+ computed. When the next character is at or beyond that position,
+ the function updates DISP_POS with the position of the next display
+ string. STRING->s is the C string to iterate, or NULL if iterating
+ over a buffer or a Lisp string; in the latter case, STRING->lstring
+ is the Lisp string. */
+static inline int
+bidi_fetch_char (EMACS_INT bytepos, EMACS_INT charpos, EMACS_INT *disp_pos,
+ struct bidi_string_data *string,
+ int frame_window_p, EMACS_INT *ch_len, EMACS_INT *nchars)
+{
+ int ch;
+ EMACS_INT endpos =
+ (string->s || STRINGP (string->lstring)) ? string->schars : ZV;
+ struct text_pos pos;
+
+ /* If we got past the last known position of display string, compute
+ the position of the next one. That position could be at CHARPOS. */
+ if (charpos < endpos && charpos > *disp_pos)
+ {
+ SET_TEXT_POS (pos, charpos, bytepos);
+ *disp_pos = compute_display_string_pos (&pos, string, frame_window_p);
+ }
+
+ /* Fetch the character at BYTEPOS. */
+ if (charpos >= endpos)
+ {
+ ch = BIDI_EOB;
+ *ch_len = 1;
+ *nchars = 1;
+ *disp_pos = endpos;
+ }
+ else if (charpos >= *disp_pos)
+ {
+ EMACS_INT disp_end_pos;
+
+ /* We don't expect to find ourselves in the middle of a display
+ property. Hopefully, it will never be needed. */
+ if (charpos > *disp_pos)
+ abort ();
+ /* Return the Unicode Object Replacement Character to represent
+ the entire run of characters covered by the display string. */
+ ch = 0xFFFC;
+ disp_end_pos = compute_display_string_end (*disp_pos, string);
+ *nchars = disp_end_pos - *disp_pos;
+ if (*nchars <= 0)
+ abort ();
+ if (string->s)
+ *ch_len = bidi_count_bytes (string->s, *disp_pos, bytepos,
+ disp_end_pos, string->unibyte);
+ else if (STRINGP (string->lstring))
+ *ch_len = bidi_count_bytes (SDATA (string->lstring), *disp_pos,
+ bytepos, disp_end_pos, string->unibyte);
+ else
+ *ch_len = CHAR_TO_BYTE (disp_end_pos) - bytepos;
+ }
+ else
+ {
+ if (string->s)
+ {
+ int len;
+
+ if (!string->unibyte)
+ {
+ ch = STRING_CHAR_AND_LENGTH (string->s + bytepos, len);
+ *ch_len = len;
+ }
+ else
+ {
+ ch = UNIBYTE_TO_CHAR (string->s[bytepos]);
+ *ch_len = 1;
+ }
+ }
+ else if (STRINGP (string->lstring))
+ {
+ int len;
+
+ if (!string->unibyte)
+ {
+ ch = STRING_CHAR_AND_LENGTH (SDATA (string->lstring) + bytepos,
+ len);
+ *ch_len = len;
+ }
+ else
+ {
+ ch = UNIBYTE_TO_CHAR (SREF (string->lstring, bytepos));
+ *ch_len = 1;
+ }
+ }
+ else
+ {
+ ch = FETCH_MULTIBYTE_CHAR (bytepos);
+ *ch_len = CHAR_BYTES (ch);
+ }
+ *nchars = 1;
+ }
+
+ /* If we just entered a run of characters covered by a display
+ string, compute the position of the next display string. */
+ if (charpos + *nchars <= endpos && charpos + *nchars > *disp_pos)
+ {
+ SET_TEXT_POS (pos, charpos + *nchars, bytepos + *ch_len);
+ *disp_pos = compute_display_string_pos (&pos, string, frame_window_p);
+ }
+
+ return ch;
+}
+
+\f
+/***********************************************************************
+ Determining paragraph direction
+ ***********************************************************************/
+
+/* Check if buffer position CHARPOS/BYTEPOS is the end of a paragraph.
+ Value is the non-negative length of the paragraph separator
+ following the buffer position, -1 if position is at the beginning
+ of a new paragraph, or -2 if position is neither at beginning nor
+ at end of a paragraph. */
+static EMACS_INT
+bidi_at_paragraph_end (EMACS_INT charpos, EMACS_INT bytepos)
+{
+ Lisp_Object sep_re;
+ Lisp_Object start_re;
+ EMACS_INT val;
+
+ sep_re = paragraph_separate_re;
+ start_re = paragraph_start_re;
+
+ val = fast_looking_at (sep_re, charpos, bytepos, ZV, ZV_BYTE, Qnil);
+ if (val < 0)
+ {
+ if (fast_looking_at (start_re, charpos, bytepos, ZV, ZV_BYTE, Qnil) >= 0)
+ val = -1;
+ else
+ val = -2;
+ }
+
+ return val;
+}
+
/* Find the beginning of this paragraph by looking back in the buffer.
Value is the byte position of the paragraph's beginning. */
static EMACS_INT
while (pos_byte > BEGV_BYTE
&& fast_looking_at (re, pos, pos_byte, limit, limit_byte, Qnil) < 0)
{
+ /* FIXME: What if the paragraph beginning is covered by a
+ display string? And what if a display string covering some
+ of the text over which we scan back includes
+ paragraph_start_re? */
pos = find_next_newline_no_quit (pos - 1, -1);
pos_byte = CHAR_TO_BYTE (pos);
}
R2L, just use that. Otherwise, determine the paragraph direction
from the first strong directional character of the paragraph.
- NO_DEFAULT_P non-nil means don't default to L2R if the paragraph
+ NO_DEFAULT_P non-zero means don't default to L2R if the paragraph
has no strong directional characters and both DIR and
bidi_it->paragraph_dir are NEUTRAL_DIR. In that case, search back
in the buffer until a paragraph is found with a strong character,
bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, int no_default_p)
{
EMACS_INT bytepos = bidi_it->bytepos;
+ int string_p = bidi_it->string.s != NULL || STRINGP (bidi_it->string.lstring);
EMACS_INT pstartbyte;
+ /* Note that begbyte is a byte position, while end is a character
+ position. Yes, this is ugly, but we are trying to avoid costly
+ calls to BYTE_TO_CHAR and its ilk. */
+ EMACS_INT begbyte = string_p ? 0 : BEGV_BYTE;
+ EMACS_INT end = string_p ? bidi_it->string.schars : ZV;
/* Special case for an empty buffer. */
- if (bytepos == BEGV_BYTE && bytepos == ZV_BYTE)
+ if (bytepos == begbyte && bidi_it->charpos == end)
dir = L2R;
/* We should never be called at EOB or before BEGV. */
- else if (bytepos >= ZV_BYTE || bytepos < BEGV_BYTE)
+ else if (bidi_it->charpos >= end || bytepos < begbyte)
abort ();
if (dir == L2R)
}
else if (dir == NEUTRAL_DIR) /* P2 */
{
- int ch, ch_len;
- EMACS_INT pos;
+ int ch;
+ EMACS_INT ch_len, nchars;
+ EMACS_INT pos, disp_pos = -1;
bidi_type_t type;
+ const unsigned char *s;
if (!bidi_initialized)
bidi_initialize ();
we are potentially in a new paragraph that doesn't yet
exist. */
pos = bidi_it->charpos;
- if (bytepos > BEGV_BYTE && FETCH_CHAR (bytepos) == '\n')
+ s = STRINGP (bidi_it->string.lstring) ?
+ SDATA (bidi_it->string.lstring) : bidi_it->string.s;
+ if (bytepos > begbyte
+ && bidi_char_at_pos (bytepos, s, bidi_it->string.unibyte) == '\n')
{
bytepos++;
pos++;
/* We are either at the beginning of a paragraph or in the
middle of it. Find where this paragraph starts. */
- pstartbyte = bidi_find_paragraph_start (pos, bytepos);
+ if (string_p)
+ {
+ /* We don't support changes of paragraph direction inside a
+ string. It is treated as a single paragraph. */
+ pstartbyte = 0;
+ }
+ else
+ pstartbyte = bidi_find_paragraph_start (pos, bytepos);
bidi_it->separator_limit = -1;
bidi_it->new_paragraph = 0;
/* The following loop is run more than once only if NO_DEFAULT_P
- is non-zero. */
+ is non-zero, and only if we are iterating on a buffer. */
do {
bytepos = pstartbyte;
- ch = FETCH_CHAR (bytepos);
- ch_len = CHAR_BYTES (ch);
- pos = BYTE_TO_CHAR (bytepos);
+ if (!string_p)
+ pos = BYTE_TO_CHAR (bytepos);
+ ch = bidi_fetch_char (bytepos, pos, &disp_pos, &bidi_it->string,
+ bidi_it->frame_window_p, &ch_len, &nchars);
type = bidi_get_type (ch, NEUTRAL_DIR);
- for (pos++, bytepos += ch_len;
+ for (pos += nchars, bytepos += ch_len;
/* NOTE: UAX#9 says to search only for L, AL, or R types
of characters, and ignore RLE, RLO, LRE, and LRO.
However, I'm not sure it makes sense to omit those 4;
|| type == LRE || type == LRO));
type = bidi_get_type (ch, NEUTRAL_DIR))
{
- if (type == NEUTRAL_B && bidi_at_paragraph_end (pos, bytepos) >= -1)
- break;
- if (bytepos >= ZV_BYTE)
+ if (pos >= end)
{
/* Pretend there's a paragraph separator at end of
- buffer. */
+ buffer/string. */
type = NEUTRAL_B;
break;
}
- FETCH_CHAR_ADVANCE (ch, pos, bytepos);
+ if (!string_p
+ && type == NEUTRAL_B
+ && bidi_at_paragraph_end (pos, bytepos) >= -1)
+ break;
+ /* Fetch next character and advance to get past it. */
+ ch = bidi_fetch_char (bytepos, pos, &disp_pos, &bidi_it->string,
+ bidi_it->frame_window_p, &ch_len, &nchars);
+ pos += nchars;
+ bytepos += ch_len;
}
if (type == STRONG_R || type == STRONG_AL) /* P3 */
bidi_it->paragraph_dir = R2L;
else if (type == STRONG_L)
bidi_it->paragraph_dir = L2R;
- if (no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR)
+ if (!string_p
+ && no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR)
{
/* If this paragraph is at BEGV, default to L2R. */
if (pstartbyte == BEGV_BYTE)
/* Find the beginning of the previous paragraph, if any. */
while (pbyte > BEGV_BYTE && prevpbyte >= pstartbyte)
{
+ /* FXIME: What if p is covered by a display
+ string? See also a FIXME inside
+ bidi_find_paragraph_start. */
p--;
pbyte = CHAR_TO_BYTE (p);
prevpbyte = bidi_find_paragraph_start (p, pbyte);
pstartbyte = prevpbyte;
}
}
- } while (no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR);
+ } while (!string_p
+ && no_default_p && bidi_it->paragraph_dir == NEUTRAL_DIR);
}
else
abort ();
bidi_line_init (bidi_it);
}
-/* Do whatever UAX#9 clause X8 says should be done at paragraph's
- end. */
-static INLINE void
-bidi_set_paragraph_end (struct bidi_it *bidi_it)
-{
- bidi_it->invalid_levels = 0;
- bidi_it->invalid_rl_levels = -1;
- bidi_it->stack_idx = 0;
- bidi_it->resolved_level = bidi_it->level_stack[0].level;
-}
+\f
+/***********************************************************************
+ Resolving explicit and implicit levels.
+ The rest of this file constitutes the core of the UBA implementation.
+ ***********************************************************************/
-/* Initialize the bidi iterator from buffer position CHARPOS. */
-void
-bidi_init_it (EMACS_INT charpos, EMACS_INT bytepos, struct bidi_it *bidi_it)
+static inline int
+bidi_explicit_dir_char (int ch)
{
- if (! bidi_initialized)
- bidi_initialize ();
- bidi_it->charpos = charpos;
- bidi_it->bytepos = bytepos;
- bidi_it->first_elt = 1;
- bidi_set_paragraph_end (bidi_it);
- bidi_it->new_paragraph = 1;
- bidi_it->separator_limit = -1;
- bidi_it->type = NEUTRAL_B;
- bidi_it->type_after_w1 = NEUTRAL_B;
- bidi_it->orig_type = NEUTRAL_B;
- bidi_it->prev_was_pdf = 0;
- bidi_it->prev.type = bidi_it->prev.type_after_w1 =
- bidi_it->prev.orig_type = UNKNOWN_BT;
- bidi_it->last_strong.type = bidi_it->last_strong.type_after_w1 =
- bidi_it->last_strong.orig_type = UNKNOWN_BT;
- bidi_it->next_for_neutral.charpos = -1;
- bidi_it->next_for_neutral.type =
- bidi_it->next_for_neutral.type_after_w1 =
- bidi_it->next_for_neutral.orig_type = UNKNOWN_BT;
- bidi_it->prev_for_neutral.charpos = -1;
- bidi_it->prev_for_neutral.type =
- bidi_it->prev_for_neutral.type_after_w1 =
- bidi_it->prev_for_neutral.orig_type = UNKNOWN_BT;
- bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */
- bidi_cache_shrink ();
-}
+ bidi_type_t ch_type;
-/* Push the current embedding level and override status; reset the
- current level to LEVEL and the current override status to OVERRIDE. */
-static INLINE void
-bidi_push_embedding_level (struct bidi_it *bidi_it,
- int level, bidi_dir_t override)
-{
- bidi_it->stack_idx++;
- if (bidi_it->stack_idx >= BIDI_MAXLEVEL)
+ if (!bidi_initialized)
abort ();
- bidi_it->level_stack[bidi_it->stack_idx].level = level;
- bidi_it->level_stack[bidi_it->stack_idx].override = override;
-}
-
-/* Pop the embedding level and directional override status from the
- stack, and return the new level. */
-static INLINE int
-bidi_pop_embedding_level (struct bidi_it *bidi_it)
-{
- /* UAX#9 says to ignore invalid PDFs. */
- if (bidi_it->stack_idx > 0)
- bidi_it->stack_idx--;
- return bidi_it->level_stack[bidi_it->stack_idx].level;
-}
-
-/* Record in SAVED_INFO the information about the current character. */
-static INLINE void
-bidi_remember_char (struct bidi_saved_info *saved_info,
- struct bidi_it *bidi_it)
-{
- saved_info->charpos = bidi_it->charpos;
- saved_info->bytepos = bidi_it->bytepos;
- saved_info->type = bidi_it->type;
- bidi_check_type (bidi_it->type);
- saved_info->type_after_w1 = bidi_it->type_after_w1;
- bidi_check_type (bidi_it->type_after_w1);
- saved_info->orig_type = bidi_it->orig_type;
- bidi_check_type (bidi_it->orig_type);
-}
-
-/* Resolve the type of a neutral character according to the type of
- surrounding strong text and the current embedding level. */
-static INLINE bidi_type_t
-bidi_resolve_neutral_1 (bidi_type_t prev_type, bidi_type_t next_type, int lev)
-{
- /* N1: European and Arabic numbers are treated as though they were R. */
- if (next_type == WEAK_EN || next_type == WEAK_AN)
- next_type = STRONG_R;
- if (prev_type == WEAK_EN || prev_type == WEAK_AN)
- prev_type = STRONG_R;
-
- if (next_type == prev_type) /* N1 */
- return next_type;
- else if ((lev & 1) == 0) /* N2 */
- return STRONG_L;
- else
- return STRONG_R;
-}
-
-static INLINE int
-bidi_explicit_dir_char (int c)
-{
- /* FIXME: this should be replaced with a lookup table with suitable
- bits set, like standard C ctype macros do. */
- return (c == LRE_CHAR || c == LRO_CHAR
- || c == RLE_CHAR || c == RLO_CHAR || c == PDF_CHAR);
+ ch_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch));
+ return (ch_type == LRE || ch_type == LRO
+ || ch_type == RLE || ch_type == RLO
+ || ch_type == PDF);
}
/* A helper function for bidi_resolve_explicit. It advances to the
int current_level;
int new_level;
bidi_dir_t override;
+ int string_p = bidi_it->string.s != NULL || STRINGP (bidi_it->string.lstring);
- if (bidi_it->bytepos < BEGV_BYTE /* after reseat to BEGV? */
+ /* If reseat()'ed, don't advance, so as to start iteration from the
+ position where we were reseated. bidi_it->bytepos can be less
+ than BEGV_BYTE after reseat to BEGV. */
+ if (bidi_it->bytepos < (string_p ? 0 : BEGV_BYTE)
|| bidi_it->first_elt)
{
bidi_it->first_elt = 0;
- if (bidi_it->charpos < BEGV)
- bidi_it->charpos = BEGV;
- bidi_it->bytepos = CHAR_TO_BYTE (bidi_it->charpos);
+ if (string_p)
+ {
+ const unsigned char *p =
+ STRINGP (bidi_it->string.lstring)
+ ? SDATA (bidi_it->string.lstring) : bidi_it->string.s;
+
+ if (bidi_it->charpos < 0)
+ bidi_it->charpos = 0;
+ bidi_it->bytepos = bidi_count_bytes (p, 0, 0, bidi_it->charpos,
+ bidi_it->string.unibyte);
+ }
+ else
+ {
+ if (bidi_it->charpos < BEGV)
+ bidi_it->charpos = BEGV;
+ bidi_it->bytepos = CHAR_TO_BYTE (bidi_it->charpos);
+ }
}
- else if (bidi_it->bytepos < ZV_BYTE) /* don't move at ZV */
+ /* Don't move at end of buffer/string. */
+ else if (bidi_it->charpos < (string_p ? bidi_it->string.schars : ZV))
{
- bidi_it->charpos++;
+ /* Advance to the next character, skipping characters covered by
+ display strings (nchars > 1). */
+ if (bidi_it->nchars <= 0)
+ abort ();
+ bidi_it->charpos += bidi_it->nchars;
if (bidi_it->ch_len == 0)
abort ();
bidi_it->bytepos += bidi_it->ch_len;
override = bidi_it->level_stack[bidi_it->stack_idx].override;
new_level = current_level;
- /* in case it is a unibyte character (not yet implemented) */
- /* _fetch_multibyte_char_len = 1; */
- if (bidi_it->bytepos >= ZV_BYTE)
+ if (bidi_it->charpos >= (string_p ? bidi_it->string.schars : ZV))
{
curchar = BIDI_EOB;
bidi_it->ch_len = 1;
+ bidi_it->nchars = 1;
+ bidi_it->disp_pos = (string_p ? bidi_it->string.schars : ZV);
}
else
{
- curchar = FETCH_CHAR (bidi_it->bytepos);
- bidi_it->ch_len = CHAR_BYTES (curchar);
+ /* Fetch the character at BYTEPOS. If it is covered by a
+ display string, treat the entire run of covered characters as
+ a single character u+FFFC. */
+ curchar = bidi_fetch_char (bidi_it->bytepos, bidi_it->charpos,
+ &bidi_it->disp_pos, &bidi_it->string,
+ bidi_it->frame_window_p,
+ &bidi_it->ch_len, &bidi_it->nchars);
}
bidi_it->ch = curchar;
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit <= 0)
+ if (bidi_it->ignore_bn_limit <= -1)
{
if (current_level <= BIDI_MAXLEVEL - 4)
{
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit <= 0)
+ if (bidi_it->ignore_bn_limit <= -1)
{
if (current_level <= BIDI_MAXLEVEL - 5)
{
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit <= 0)
+ if (bidi_it->ignore_bn_limit <= -1)
{
if (!bidi_it->invalid_rl_levels)
{
}
/* Given an iterator state in BIDI_IT, advance one character position
- in the buffer to the next character (in the logical order), resolve
- any explicit embeddings and directional overrides, and return the
- embedding level of the character after resolving explicit
- directives and ignoring empty embeddings. */
+ in the buffer/string to the next character (in the logical order),
+ resolve any explicit embeddings and directional overrides, and
+ return the embedding level of the character after resolving
+ explicit directives and ignoring empty embeddings. */
static int
bidi_resolve_explicit (struct bidi_it *bidi_it)
{
int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
int new_level = bidi_resolve_explicit_1 (bidi_it);
+ EMACS_INT eob = bidi_it->string.s ? bidi_it->string.schars : ZV;
+ const unsigned char *s = STRINGP (bidi_it->string.lstring)
+ ? SDATA (bidi_it->string.lstring) : bidi_it->string.s;
if (prev_level < new_level
&& bidi_it->type == WEAK_BN
- && bidi_it->ignore_bn_limit == 0 /* only if not already known */
- && bidi_it->bytepos < ZV_BYTE /* not already at EOB */
- && bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
- + bidi_it->ch_len)))
+ && bidi_it->ignore_bn_limit == -1 /* only if not already known */
+ && bidi_it->charpos < eob /* not already at EOB */
+ && bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos
+ + bidi_it->ch_len, s,
+ bidi_it->string.unibyte)))
{
/* Avoid pushing and popping embedding levels if the level run
is empty, as this breaks level runs where it shouldn't.
bidi_copy_it (&saved_it, bidi_it);
- while (bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
- + bidi_it->ch_len)))
+ while (bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos
+ + bidi_it->ch_len, s,
+ bidi_it->string.unibyte)))
{
+ /* This advances to the next character, skipping any
+ characters covered by display strings. */
level = bidi_resolve_explicit_1 (bidi_it);
+ /* If string.lstring was relocated inside bidi_resolve_explicit_1,
+ a pointer to its data is no longer valid. */
+ if (STRINGP (bidi_it->string.lstring))
+ s = SDATA (bidi_it->string.lstring);
}
+ if (bidi_it->nchars <= 0)
+ abort ();
if (level == prev_level) /* empty embedding */
- saved_it.ignore_bn_limit = bidi_it->charpos + 1;
+ saved_it.ignore_bn_limit = bidi_it->charpos + bidi_it->nchars;
else /* this embedding is non-empty */
- saved_it.ignore_bn_limit = -1;
+ saved_it.ignore_bn_limit = -2;
bidi_copy_it (bidi_it, &saved_it);
- if (bidi_it->ignore_bn_limit > 0)
+ if (bidi_it->ignore_bn_limit > -1)
{
/* We pushed a level, but we shouldn't have. Undo that. */
if (!bidi_it->invalid_rl_levels)
return new_level;
}
-/* Advance in the buffer, resolve weak types and return the type of
- the next character after weak type resolution. */
+/* Advance in the buffer/string, resolve weak types and return the
+ type of the next character after weak type resolution. */
static bidi_type_t
bidi_resolve_weak (struct bidi_it *bidi_it)
{
int next_char;
bidi_type_t type_of_next;
struct bidi_it saved_it;
+ EMACS_INT eob =
+ (STRINGP (bidi_it->string.lstring) || bidi_it->string.s)
+ ? bidi_it->string.schars : ZV;
type = bidi_it->type;
override = bidi_it->level_stack[bidi_it->stack_idx].override;
&& bidi_it->prev.orig_type == WEAK_EN)
|| bidi_it->prev.type_after_w1 == WEAK_AN)))
{
+ const unsigned char *s =
+ STRINGP (bidi_it->string.lstring)
+ ? SDATA (bidi_it->string.lstring) : bidi_it->string.s;
+
next_char =
- bidi_it->bytepos + bidi_it->ch_len >= ZV_BYTE
- ? BIDI_EOB : FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
+ bidi_it->charpos + bidi_it->nchars >= eob
+ ? BIDI_EOB
+ : bidi_char_at_pos (bidi_it->bytepos + bidi_it->ch_len, s,
+ bidi_it->string.unibyte);
type_of_next = bidi_get_type (next_char, override);
if (type_of_next == WEAK_BN
type = WEAK_EN;
else /* W5: ET/BN with EN after it. */
{
- EMACS_INT en_pos = bidi_it->charpos + 1;
+ EMACS_INT en_pos = bidi_it->charpos + bidi_it->nchars;
+ const unsigned char *s =
+ STRINGP (bidi_it->string.lstring)
+ ? SDATA (bidi_it->string.lstring) : bidi_it->string.s;
+ if (bidi_it->nchars <= 0)
+ abort ();
next_char =
- bidi_it->bytepos + bidi_it->ch_len >= ZV_BYTE
- ? BIDI_EOB : FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
+ bidi_it->charpos + bidi_it->nchars >= eob
+ ? BIDI_EOB
+ : bidi_char_at_pos (bidi_it->bytepos + bidi_it->ch_len, s,
+ bidi_it->string.unibyte);
type_of_next = bidi_get_type (next_char, override);
if (type_of_next == WEAK_ET
return type;
}
+/* Resolve the type of a neutral character according to the type of
+ surrounding strong text and the current embedding level. */
+static inline bidi_type_t
+bidi_resolve_neutral_1 (bidi_type_t prev_type, bidi_type_t next_type, int lev)
+{
+ /* N1: European and Arabic numbers are treated as though they were R. */
+ if (next_type == WEAK_EN || next_type == WEAK_AN)
+ next_type = STRONG_R;
+ if (prev_type == WEAK_EN || prev_type == WEAK_AN)
+ prev_type = STRONG_R;
+
+ if (next_type == prev_type) /* N1 */
+ return next_type;
+ else if ((lev & 1) == 0) /* N2 */
+ return STRONG_L;
+ else
+ return STRONG_R;
+}
+
static bidi_type_t
bidi_resolve_neutral (struct bidi_it *bidi_it)
{
/* Arrrgh!! The UAX#9 algorithm is too deeply entrenched in
the assumption of batch-style processing; see clauses W4,
W5, and especially N1, which require to look far forward
- (as well as back) in the buffer. May the fleas of a
- thousand camels infest the armpits of those who design
+ (as well as back) in the buffer/string. May the fleas of
+ a thousand camels infest the armpits of those who design
supposedly general-purpose algorithms by looking at their
own implementations, and fail to consider other possible
implementations! */
}
/* Given an iterator state in BIDI_IT, advance one character position
- in the buffer to the next character (in the logical order), resolve
- the bidi type of that next character, and return that type. */
+ in the buffer/string to the next character (in the logical order),
+ resolve the bidi type of that next character, and return that
+ type. */
static bidi_type_t
bidi_type_of_next_char (struct bidi_it *bidi_it)
{
/* Reset the limit until which to ignore BNs if we step out of the
area where we found only empty levels. */
- if ((bidi_it->ignore_bn_limit > 0
+ if ((bidi_it->ignore_bn_limit > -1
&& bidi_it->ignore_bn_limit <= bidi_it->charpos)
- || (bidi_it->ignore_bn_limit == -1
+ || (bidi_it->ignore_bn_limit == -2
&& !bidi_explicit_dir_char (bidi_it->ch)))
- bidi_it->ignore_bn_limit = 0;
+ bidi_it->ignore_bn_limit = -1;
type = bidi_resolve_neutral (bidi_it);
}
/* Given an iterator state BIDI_IT, advance one character position in
- the buffer to the next character (in the logical order), resolve
- the embedding and implicit levels of that next character, and
- return the resulting level. */
+ the buffer/string to the next character (in the current scan
+ direction), resolve the embedding and implicit levels of that next
+ character, and return the resulting level. */
static int
bidi_level_of_next_char (struct bidi_it *bidi_it)
{
bidi_type_t type;
int level, prev_level = -1;
struct bidi_saved_info next_for_neutral;
+ EMACS_INT next_char_pos = -2;
if (bidi_it->scan_dir == 1)
{
+ EMACS_INT eob =
+ (bidi_it->string.s || STRINGP (bidi_it->string.lstring))
+ ? bidi_it->string.schars : ZV;
+
/* There's no sense in trying to advance if we hit end of text. */
- if (bidi_it->bytepos >= ZV_BYTE)
+ if (bidi_it->charpos >= eob)
return bidi_it->resolved_level;
/* Record the info about the previous character. */
}
next_for_neutral = bidi_it->next_for_neutral;
- /* Perhaps it is already cached. */
- type = bidi_cache_find (bidi_it->charpos + bidi_it->scan_dir, -1, bidi_it);
+ /* Perhaps the character we want is already cached. If it is, the
+ call to bidi_cache_find below will return a type other than
+ UNKNOWN_BT. */
+ if (bidi_cache_idx > bidi_cache_start && !bidi_it->first_elt)
+ {
+ int bob =
+ (bidi_it->string.s || STRINGP (bidi_it->string.lstring)) ? 0 : 1;
+
+ if (bidi_it->scan_dir > 0)
+ {
+ if (bidi_it->nchars <= 0)
+ abort ();
+ next_char_pos = bidi_it->charpos + bidi_it->nchars;
+ }
+ else if (bidi_it->charpos >= bob)
+ /* Implementation note: we allow next_char_pos to be as low as
+ 0 for buffers or -1 for strings, and that is okay because
+ that's the "position" of the sentinel iterator state we
+ cached at the beginning of the iteration. */
+ next_char_pos = bidi_it->charpos - 1;
+ if (next_char_pos >= bob - 1)
+ type = bidi_cache_find (next_char_pos, -1, bidi_it);
+ else
+ type = UNKNOWN_BT;
+ }
+ else
+ type = UNKNOWN_BT;
if (type != UNKNOWN_BT)
{
/* Don't lose the information for resolving neutrals! The
&& bidi_it->next_for_ws.type == UNKNOWN_BT)
{
int ch;
- int clen = bidi_it->ch_len;
+ EMACS_INT clen = bidi_it->ch_len;
EMACS_INT bpos = bidi_it->bytepos;
EMACS_INT cpos = bidi_it->charpos;
+ EMACS_INT disp_pos = bidi_it->disp_pos;
+ EMACS_INT nc = bidi_it->nchars;
+ struct bidi_string_data bs = bidi_it->string;
bidi_type_t chtype;
+ int fwp = bidi_it->frame_window_p;
+ if (bidi_it->nchars <= 0)
+ abort ();
do {
- /*_fetch_multibyte_char_len = 1;*/
- ch = bpos + clen >= ZV_BYTE ? BIDI_EOB : FETCH_CHAR (bpos + clen);
- bpos += clen;
- cpos++;
- clen = (ch == BIDI_EOB ? 1 : CHAR_BYTES (ch));
+ ch = bidi_fetch_char (bpos += clen, cpos += nc, &disp_pos, &bs, fwp,
+ &clen, &nc);
if (ch == '\n' || ch == BIDI_EOB /* || ch == LINESEP_CHAR */)
chtype = NEUTRAL_B;
else
If this level's other edge is cached, we simply jump to it, filling
the iterator structure with the iterator state on the other edge.
- Otherwise, we walk the buffer until we come back to the same level
- as LEVEL.
+ Otherwise, we walk the buffer or string until we come back to the
+ same level as LEVEL.
Note: we are not talking here about a ``level run'' in the UAX#9
sense of the term, but rather about a ``level'' which includes
bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, int end_flag)
{
int dir = end_flag ? -bidi_it->scan_dir : bidi_it->scan_dir;
- int idx;
+ EMACS_INT idx;
/* Try the cache first. */
- if ((idx = bidi_cache_find_level_change (level, dir, end_flag)) >= 0)
+ if ((idx = bidi_cache_find_level_change (level, dir, end_flag))
+ >= bidi_cache_start)
bidi_cache_fetch_state (idx, bidi_it);
else
{
{
int old_level, new_level, next_level;
struct bidi_it sentinel;
+ struct gcpro gcpro1;
+
+ if (bidi_it->charpos < 0 || bidi_it->bytepos < 0)
+ abort ();
if (bidi_it->scan_dir == 0)
{
bidi_it->scan_dir = 1; /* default to logical order */
}
+ /* The code below can call eval, and thus cause GC. If we are
+ iterating a Lisp string, make sure it won't be GCed. */
+ if (STRINGP (bidi_it->string.lstring))
+ GCPRO1 (bidi_it->string.lstring);
+
/* If we just passed a newline, initialize for the next line. */
if (!bidi_it->first_elt && bidi_it->orig_type == NEUTRAL_B)
bidi_line_init (bidi_it);
/* Prepare the sentinel iterator state, and cache it. When we bump
into it, scanning backwards, we'll know that the last non-base
level is exhausted. */
- if (bidi_cache_idx == 0)
+ if (bidi_cache_idx == bidi_cache_start)
{
bidi_copy_it (&sentinel, bidi_it);
if (bidi_it->first_elt)
sentinel.bytepos--;
sentinel.ch = '\n'; /* doesn't matter, but why not? */
sentinel.ch_len = 1;
+ sentinel.nchars = 1;
}
bidi_cache_iterator_state (&sentinel, 1);
}
reordering, whereas we _must_ know the paragraph base direction
_before_ we process the paragraph's text, since the base
direction affects the reordering. */
- if (bidi_it->scan_dir == 1
- && bidi_it->orig_type == NEUTRAL_B
- && bidi_it->bytepos < ZV_BYTE)
+ if (bidi_it->scan_dir == 1 && bidi_it->orig_type == NEUTRAL_B)
{
- EMACS_INT sep_len =
- bidi_at_paragraph_end (bidi_it->charpos + 1,
- bidi_it->bytepos + bidi_it->ch_len);
- if (sep_len >= 0)
+ /* The paragraph direction of the entire string, once
+ determined, is in effect for the entire string. Setting the
+ separator limit to the end of the string prevents
+ bidi_paragraph_init from being called automatically on this
+ string. */
+ if (bidi_it->string.s || STRINGP (bidi_it->string.lstring))
+ bidi_it->separator_limit = bidi_it->string.schars;
+ else if (bidi_it->bytepos < ZV_BYTE)
{
- bidi_it->new_paragraph = 1;
- /* Record the buffer position of the last character of the
- paragraph separator. */
- bidi_it->separator_limit = bidi_it->charpos + 1 + sep_len;
+ EMACS_INT sep_len =
+ bidi_at_paragraph_end (bidi_it->charpos + bidi_it->nchars,
+ bidi_it->bytepos + bidi_it->ch_len);
+ if (bidi_it->nchars <= 0)
+ abort ();
+ if (sep_len >= 0)
+ {
+ bidi_it->new_paragraph = 1;
+ /* Record the buffer position of the last character of the
+ paragraph separator. */
+ bidi_it->separator_limit =
+ bidi_it->charpos + bidi_it->nchars + sep_len;
+ }
}
}
- if (bidi_it->scan_dir == 1 && bidi_cache_idx)
+ if (bidi_it->scan_dir == 1 && bidi_cache_idx > bidi_cache_start)
{
/* If we are at paragraph's base embedding level and beyond the
last cached position, the cache's job is done and we can
discard it. */
if (bidi_it->resolved_level == bidi_it->level_stack[0].level
- && bidi_it->charpos > bidi_cache[bidi_cache_idx - 1].charpos)
+ && bidi_it->charpos > (bidi_cache[bidi_cache_idx - 1].charpos
+ + bidi_cache[bidi_cache_idx - 1].nchars - 1))
bidi_cache_reset ();
/* But as long as we are caching during forward scan, we must
cache each state, or else the cache integrity will be
else
bidi_cache_iterator_state (bidi_it, 1);
}
+
+ if (STRINGP (bidi_it->string.lstring))
+ UNGCPRO;
}
/* This is meant to be called from within the debugger, whenever you
fprintf (stderr, "The cache is empty.\n");
return;
}
- fprintf (stderr, "Total of %d state%s in cache:\n",
+ fprintf (stderr, "Total of %"pD"d state%s in cache:\n",
bidi_cache_idx, bidi_cache_idx == 1 ? "" : "s");
for (i = bidi_cache[bidi_cache_idx - 1].charpos; i > 0; i /= 10)