-/* 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
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. */
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++;
+ if (bidi_it->stack_idx >= BIDI_MAXLEVEL)
+ 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);
+}
+
/* 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
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;
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
+/***********************************************************************
+ Initialization
+ ***********************************************************************/
+static void
+bidi_initialize (void)
{
- Lisp_Object sep_re;
- Lisp_Object start_re;
- EMACS_INT val;
- sep_re = paragraph_separate_re;
- start_re = paragraph_start_re;
+#include "biditype.h"
+#include "bidimirror.h"
- 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;
- }
+ int i;
- return val;
+ 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;
}
-/* 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. */
+/* Do whatever UAX#9 clause X8 says should be done at paragraph's
+ end. */
static INLINE void
-bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
+bidi_set_paragraph_end (struct bidi_it *bidi_it)
{
- 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->invalid_levels = 0;
+ bidi_it->invalid_rl_levels = -1;
+ bidi_it->stack_idx = 0;
+ bidi_it->resolved_level = bidi_it->level_stack[0].level;
+}
- bidi_it->prev.type = UNKNOWN_BT;
+/* 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 = -1; /* 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 ();
}
/* Perform initializations for reordering a new line of bidi text. */
bidi_cache_reset ();
}
+\f
+/***********************************************************************
+ Fetching characters
+ ***********************************************************************/
+
/* Count bytes in multibyte string S between BEG/BEGBYTE and END. BEG
and END are zero-based character positions in S, BEGBYTE is byte
position corresponding to BEG. */
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
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;
-}
-
-/* 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->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_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 ();
-}
-
-/* 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)
- 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;
-}
+\f
+/***********************************************************************
+ Resolving explicit and implicit levels.
+ The rest of the file constitutes the core
+ of the UBA implementation.
+ ***********************************************************************/
static INLINE int
bidi_explicit_dir_char (int ch)
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)
{
HCoop / bpt / emacs.git / commitdiff