/* Low-level bidirectional buffer-scanning functions for GNU Emacs.
- Copyright (C) 2000, 2001, 2004, 2005, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2004, 2005, 2009, 2010
+ Free Software Foundation, Inc.
This file is part of GNU Emacs.
-GNU Emacs is free software; you can redistribute it and/or modify
+GNU Emacs 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 2, or (at your option)
-any later version.
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
-the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-Boston, MA 02110-1301, USA. */
+along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Eli Zaretskii <eliz@gnu.org>.
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.
+ designed to be called once for every character in the buffer or
+ string.
The main entry point is bidi_get_next_char_visually. Each time it
is called, it finds the next character in the visual order, and
more 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
+ bidi_mirror_char. The first determines the base direction of a
+ paragraph, while the second returns the mirrored version of its
+ argument character.
+
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.
make_number (bidi_type[i].type));
fallback_paragraph_start_re =
- XSYMBOL (Fintern_soft (build_string ("paragraph-start"), Qnil))->value;
+ Fsymbol_value (Fintern_soft (build_string ("paragraph-start"), Qnil));
if (!STRINGP (fallback_paragraph_start_re))
fallback_paragraph_start_re = build_string ("\f\\|[ \t]*$");
staticpro (&fallback_paragraph_start_re);
Qparagraph_start = intern ("paragraph-start");
staticpro (&Qparagraph_start);
fallback_paragraph_separate_re =
- XSYMBOL (Fintern_soft (build_string ("paragraph-separate"), Qnil))->value;
+ Fsymbol_value (Fintern_soft (build_string ("paragraph-separate"), Qnil));
if (!STRINGP (fallback_paragraph_separate_re))
fallback_paragraph_separate_re = build_string ("[ \t\f]*$");
staticpro (&fallback_paragraph_separate_re);
/* Return the bidi type of a character CH, subject to the current
directional OVERRIDE. */
-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. */
-bidi_category_t
+static INLINE bidi_category_t
bidi_get_category (bidi_type_t type)
{
switch (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;
static int bidi_cache_idx;
static int bidi_cache_last_idx;
-static inline void
+static INLINE void
bidi_cache_reset (void)
{
bidi_cache_idx = 0;
bidi_cache_last_idx = -1;
}
-static inline void
+static INLINE void
bidi_cache_fetch_state (int idx, struct bidi_it *bidi_it)
{
int current_scan_dir = bidi_it->scan_dir;
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 int
bidi_cache_search (int charpos, int level, int dir)
{
int i, i_start;
return -1;
}
-static inline void
+static INLINE void
bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
{
int idx;
/* Don't overrun the cache limit. */
if (idx > sizeof (bidi_cache) / sizeof (bidi_cache[0]) - 1)
abort ();
- /* Don't violate cache integrity: character positions should
- correspond to cache positions 1:1. */
- if (idx > 0 && bidi_it->charpos != bidi_cache[idx - 1].charpos + 1)
- abort ();
+ /* 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))
+ {
+ bidi_cache_reset ();
+ idx = 0;
+ }
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 (int charpos, int level, struct bidi_it *bidi_it)
{
int i = bidi_cache_search (charpos, level, bidi_it->scan_dir);
{
bidi_dir_t current_scan_dir = bidi_it->scan_dir;
- *bidi_it = bidi_cache[i];
+ bidi_copy_it (bidi_it, &bidi_cache[i]);
bidi_cache_last_idx = i;
/* Don't let scan direction from from the cached state override
the current scan direction. */
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)
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. */
-EMACS_INT
+static EMACS_INT
bidi_at_paragraph_end (EMACS_INT charpos, EMACS_INT bytepos)
{
Lisp_Object sep_re = Fbuffer_local_value (Qparagraph_separate,
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
+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;
int ch, ch_len;
EMACS_INT pos;
bidi_type_t type;
- EMACS_INT sep_len;
/* If we are inside a paragraph separator, we are just waiting
for the separator to be exhausted; use the previous paragraph
/* Do whatever UAX#9 clause X8 says should be done at paragraph's
end. */
-static inline void
+static INLINE void
bidi_set_paragraph_end (struct bidi_it *bidi_it)
{
bidi_it->invalid_levels = 0;
bidi_set_paragraph_end (bidi_it);
bidi_it->new_paragraph = 1;
bidi_it->separator_limit = -1;
- bidi_it->paragraph_dir = NEUTRAL_DIR;
bidi_it->type = NEUTRAL_B;
- bidi_it->type_after_w1 = UNKNOWN_BT;
- bidi_it->orig_type = UNKNOWN_BT;
+ 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 = UNKNOWN_BT;
+ 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;
/* Push the current embedding level and override status; reset the
current level to LEVEL and the current override status to OVERRIDE. */
-static inline void
+static INLINE void
bidi_push_embedding_level (struct bidi_it *bidi_it,
int level, bidi_dir_t override)
{
/* Pop the embedding level and directional override status from the
stack, and return the new level. */
-static inline int
+static INLINE int
bidi_pop_embedding_level (struct bidi_it *bidi_it)
{
/* UAX#9 says to ignore invalid PDFs. */
}
/* Record in SAVED_INFO the information about the current character. */
-static inline void
+static INLINE void
bidi_remember_char (struct bidi_saved_info *saved_info,
struct bidi_it *bidi_it)
{
/* 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
+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. */
return STRONG_R;
}
-static inline int
+static INLINE int
bidi_explicit_dir_char (int c)
{
/* FIXME: this should be replaced with a lookup table with suitable
if (prev_level < new_level
&& bidi_it->type == WEAK_BN
&& bidi_it->ignore_bn_limit == 0 /* only if not already known */
- && bidi_it->ch != BIDI_EOB /* not already at EOB */
+ && bidi_it->bytepos < ZV_BYTE /* not already at EOB */
&& bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
+ bidi_it->ch_len)))
{
/* Advance in the buffer, resolve weak types and return the type of
the next character after weak type resolution. */
-bidi_type_t
+static bidi_type_t
bidi_resolve_weak (struct bidi_it *bidi_it)
{
bidi_type_t type;
if (type == WEAK_NSM) /* W1 */
{
/* Note that we don't need to consider the case where the
- prev character has its type overridden by an RLO or LRO:
- such characters are outside the current level run, and
- thus not relevant to this NSM. Thus, NSM gets the
- orig_type of the previous character. */
- if (bidi_it->prev.type != UNKNOWN_BT)
- type = bidi_it->prev.orig_type;
+ prev character has its type overridden by an RLO or LRO,
+ because then either the type of this NSM would have been
+ also overridden, or the previous character is outside the
+ current level run, and thus not relevant to this NSM.
+ This is why NSM gets the type_after_w1 of the previous
+ character. */
+ if (bidi_it->prev.type_after_w1 != UNKNOWN_BT
+ /* if type_after_w1 is NEUTRAL_B, this NSM is at sor */
+ && bidi_it->prev.type_after_w1 != NEUTRAL_B)
+ type = bidi_it->prev.type_after_w1;
else if (bidi_it->sor == R2L)
type = STRONG_R;
else if (bidi_it->sor == L2R)
return type;
}
-bidi_type_t
+static bidi_type_t
bidi_resolve_neutral (struct bidi_it *bidi_it)
{
int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
/* 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. */
-bidi_type_t
+static bidi_type_t
bidi_type_of_next_char (struct bidi_it *bidi_it)
{
bidi_type_t type;
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. */
-int
+static int
bidi_level_of_next_char (struct bidi_it *bidi_it)
{
bidi_type_t type;
if (bidi_it->scan_dir == 1)
{
/* There's no sense in trying to advance if we hit end of text. */
- if (bidi_it->ch == BIDI_EOB)
+ if (bidi_it->bytepos >= ZV_BYTE)
return bidi_it->resolved_level;
/* Record the info about the previous character. */
/* Reordering of resolved levels (clause L2) is implemented by
jumping to the other edge of the level and flipping direction of
- scanning the buffer whenever we find a level change. */
+ scanning the text whenever we find a level change. */
if (new_level != old_level)
{
int ascending = new_level > old_level;
paragraph direction, if needed. We do this at the newline before
the paragraph separator, because the next character might not be
the first character of the next paragraph, due to the bidi
- reordering. */
+ 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)
HCoop / bpt / emacs.git / blobdiff