From e8207eb00d5be19c9e3678cc9697504da60b68c5 Mon Sep 17 00:00:00 2001
From: Eli Zaretskii <eliz@gnu.org>
Date: Sat, 27 Sep 2014 18:38:04 +0300
Subject: [PATCH] Finished writing code for isolates and fixed a few bugs (no
parens yet).
---
src/bidi.c | 142 +++++++++++++++++++++++++++++++++--------------
src/dispextern.h | 1 -
2 files changed, 100 insertions(+), 43 deletions(-)
diff --git a/src/bidi.c b/src/bidi.c
index 5ef2dd1c31c..1cceccf0119 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -406,7 +406,7 @@ bidi_set_sos_type (struct bidi_it *bidi_it, int level_before, int level_after)
/* FIXME: should the default sos direction be user selectable? */
bidi_it->sos = ((higher_level & 1) != 0 ? R2L : L2R); /* X10 */
- bidi_it->prev.type = UNKNOWN_BT;
+ bidi_it->prev.type = bidi_it->prev.type_after_w1 = 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->sos == R2L ? STRONG_R : STRONG_L);
@@ -436,7 +436,6 @@ bidi_push_embedding_level (struct bidi_it *bidi_it,
st->last_strong = bidi_it->last_strong;
st->prev_for_neutral = bidi_it->prev_for_neutral;
st->next_for_neutral = bidi_it->next_for_neutral;
- st->next_for_ws = bidi_it->next_for_ws;
st->sos = bidi_it->sos;
}
}
@@ -472,7 +471,6 @@ bidi_pop_embedding_level (struct bidi_it *bidi_it)
bidi_it->last_strong = st.last_strong;
bidi_it->prev_for_neutral = st.prev_for_neutral;
bidi_it->next_for_neutral = st.next_for_neutral;
- bidi_it->next_for_ws = st.next_for_ws;
bidi_it->sos = st.sos;
}
bidi_it->stack_idx--;
@@ -2003,8 +2001,8 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
X10). */
bidi_set_sos_type (bidi_it, prev_level, new_level);
}
- else if (type == NEUTRAL_S || type == NEUTRAL_WS
- || type == WEAK_BN || type == STRONG_AL)
+ if (type == NEUTRAL_S || type == NEUTRAL_WS
+ || type == WEAK_BN || type == STRONG_AL)
bidi_it->type_after_w1 = type; /* needed in L1 */
bidi_check_type (bidi_it->type_after_w1);
@@ -2025,12 +2023,20 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
current level run, and thus not relevant to this NSM.
This is why NSM gets the type_after_w1 of the previous
character. */
+ /* bidi_set_sos_type sets type_after_w1 to UNKNOWN_BT. */
if (bidi_it->prev.type_after_w1 != UNKNOWN_BT
- /* if type_after_w1 is NEUTRAL_B, this NSM is at sos */
+ /* If type_after_w1 is NEUTRAL_B, this NSM is at sos. */
&& bidi_it->prev.type_after_w1 != NEUTRAL_B)
{
if (bidi_isolate_fmt_char (bidi_it->prev.type_after_w1))
- type = NEUTRAL_ON;
+ {
+ /* From W1: "Note that in an isolating run sequence,
+ an isolate initiator followed by an NSM or any
+ type other than PDI must be an overflow isolate
+ initiator." */
+ eassert (bidi_it->invalid_isolates > 0);
+ type = NEUTRAL_ON;
+ }
else
type = bidi_it->prev.type_after_w1;
}
@@ -2071,8 +2077,7 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
bidi_copy_it (&saved_it, bidi_it);
while (bidi_resolve_explicit (bidi_it) == new_level
&& bidi_it->type == WEAK_BN)
- ;
- type_of_next = bidi_it->type;
+ type_of_next = bidi_it->type;
bidi_copy_it (bidi_it, &saved_it);
}
@@ -2115,6 +2120,12 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
}
else if (bidi_it->next_en_pos >=0)
{
+ /* We overstepped the last known position for ET
+ resolution but there could be other such characters
+ in this paragraph (when we are sure there are no more
+ such positions, we set next_en_pos to a negative
+ value). Try to find the next position for ET
+ resolution. */
ptrdiff_t en_pos = bidi_it->charpos + bidi_it->nchars;
const unsigned char *s = (STRINGP (bidi_it->string.lstring)
? SDATA (bidi_it->string.lstring)
@@ -2137,9 +2148,20 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
while (bidi_resolve_explicit (bidi_it) == new_level
&& (bidi_it->type == WEAK_BN
|| bidi_it->type == WEAK_ET))
- ;
- type_of_next = bidi_it->type;
- en_pos = bidi_it->charpos;
+ type_of_next = bidi_it->type;
+ if (type == WEAK_BN
+ && bidi_it->charpos == saved_it.charpos + saved_it.nchars)
+ {
+ /* If we entered the above loop with a BN that
+ changes the level, the type of next
+ character, which is in a different level, is
+ not relevant to resolving this series of ET
+ and BN. */
+ en_pos = saved_it.charpos;
+ type_of_next = type;
+ }
+ else
+ en_pos = bidi_it->charpos;
bidi_copy_it (bidi_it, &saved_it);
}
/* Remember this position, to speed up processing of the
@@ -2199,7 +2221,8 @@ bidi_resolve_weak (struct bidi_it *bidi_it)
static 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. */
+ /* N1: "European and Arabic numbers act as if they were R in terms
+ of their influence on NIs." */
if (next_type == WEAK_EN || next_type == WEAK_AN)
next_type = STRONG_R;
if (prev_type == WEAK_EN || prev_type == WEAK_AN)
@@ -2221,21 +2244,27 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
int current_level = bidi_it->level_stack[bidi_it->stack_idx].level;
bool is_neutral = bidi_get_category (type) == NEUTRAL;
- eassert ((type == STRONG_R
- || type == STRONG_L
- || type == WEAK_BN
- || type == WEAK_EN
- || type == WEAK_AN
- || type == NEUTRAL_B
- || type == NEUTRAL_S
- || type == NEUTRAL_WS
- || type == NEUTRAL_ON));
+ eassert (type == STRONG_R
+ || type == STRONG_L
+ || type == WEAK_BN
+ || type == WEAK_EN
+ || type == WEAK_AN
+ || type == NEUTRAL_B
+ || type == NEUTRAL_S
+ || type == NEUTRAL_WS
+ || type == NEUTRAL_ON
+ || type == LRI
+ || type == RLI
+ || type == PDI);
eassert (prev_level >= 0);
eassert (current_level >= 0);
+
+ /* FIXME: Insert the code for N0 here. */
+
if ((type != NEUTRAL_B /* Don't risk entering the long loop below if
we are already at paragraph end. */
- && is_neutral)
+ && (is_neutral || bidi_isolate_fmt_char (type)))
/* N1-N2/Retaining */
|| (type == WEAK_BN && bidi_explicit_dir_char (bidi_it->ch)))
{
@@ -2258,7 +2287,8 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
entering the expensive loop in the "else" clause. */
else if (current_level == 0
&& bidi_it->prev_for_neutral.type == STRONG_L
- && !bidi_explicit_dir_char (bidi_it->ch))
+ && !bidi_explicit_dir_char (bidi_it->ch)
+ && !bidi_isolate_fmt_char (type))
type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
STRONG_L, current_level);
else if (/* current level is 1 */
@@ -2270,7 +2300,8 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
&& (bidi_it->prev_for_neutral.type == STRONG_R
|| bidi_it->prev_for_neutral.type == WEAK_EN
|| bidi_it->prev_for_neutral.type == WEAK_AN)
- && !bidi_explicit_dir_char (bidi_it->ch))
+ && !bidi_explicit_dir_char (bidi_it->ch)
+ && !bidi_isolate_fmt_char (type))
type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
STRONG_R, current_level);
else
@@ -2295,32 +2326,43 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
character, and then use that to resolve the neutral we
are dealing with now. We also cache the scanned iterator
states, to salvage some of the effort later. */
- bidi_cache_iterator_state (bidi_it, 0);
do {
+ /* Paragraph separators have their levels fully resolved
+ at this point, so cache them as resolved. */
+ bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B);
/* Record the info about the previous character, so that
- it will be cached below with this state. */
+ it will be cached with this state. */
if (bidi_it->type_after_w1 != WEAK_BN /* W1/Retaining */
&& bidi_it->type != WEAK_BN)
bidi_remember_char (&bidi_it->prev, bidi_it);
type = bidi_resolve_weak (bidi_it);
+ /* Skip level runs excluded from this isolating run sequence. */
+ if (bidi_it->level_stack[bidi_it->stack_idx].level > current_level
+ && bidi_it->level_stack[bidi_it->stack_idx].isolate_status)
+ {
+ while (bidi_it->level_stack[bidi_it->stack_idx].level
+ > current_level)
+ {
+ bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B);
+ type = bidi_resolve_weak (bidi_it);
+ }
+ }
if (!adjacent_to_neutrals
- && bidi_get_category (type) == NEUTRAL)
+ && (bidi_get_category (type) == NEUTRAL
+ || bidi_isolate_fmt_char (type)))
adjacent_to_neutrals = true;
- /* Paragraph separators have their levels fully resolved
- at this point, so cache them as resolved. */
- bidi_cache_iterator_state (bidi_it, type == NEUTRAL_B);
- /* FIXME: implement L1 here, by testing for a newline and
- resetting the level for any sequence of whitespace
- characters adjacent to it. */
} while (!(type == NEUTRAL_B
|| (type != WEAK_BN
- && bidi_get_category (type) != NEUTRAL)
+ && bidi_get_category (type) != NEUTRAL
+ && !bidi_isolate_fmt_char (type))
/* This is all per level run, so stop when we
reach the end of this level run. */
|| (bidi_it->level_stack[bidi_it->stack_idx].level
!= current_level)));
+ /* Record the character we stopped at. */
bidi_remember_char (&saved_it.next_for_neutral, bidi_it);
+
if ((bidi_it->level_stack[bidi_it->stack_idx].level != current_level)
|| type == NEUTRAL_B)
{
@@ -2352,8 +2394,8 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
break;
case WEAK_EN:
case WEAK_AN:
- /* N1: ``European and Arabic numbers are treated as
- though they were R.'' */
+ /* N1: "European and Arabic numbers act as if they
+ were R in terms of their influence on NIs." */
next_type = STRONG_R;
break;
default:
@@ -2361,12 +2403,17 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
break;
}
}
+ /* Resolve the type of all the NIs found during the above loop. */
type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type,
next_type, current_level);
+ /* Update next_for_neutral with the resolved type, so we
+ could use it for all the other NIs up to the place where
+ we exited the loop. */
saved_it.next_for_neutral.type = next_type;
+ bidi_check_type (type);
+ /* Update the character which caused us to enter the above loop. */
saved_it.type = type;
bidi_check_type (next_type);
- bidi_check_type (type);
bidi_copy_it (bidi_it, &saved_it);
}
}
@@ -2402,6 +2449,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
int level, prev_level = -1;
struct bidi_saved_info next_for_neutral;
ptrdiff_t next_char_pos = -2;
+ bool need_to_update_cache = false;
if (bidi_it->scan_dir == 1)
{
@@ -2519,6 +2567,13 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
eassert (bidi_it->resolved_level >= 0);
return bidi_it->resolved_level;
}
+ else
+ {
+ /* Take note when we've got a cached state that is not fully
+ resolved, so that we could make sure we update the cache
+ below, when we do resolve it. */
+ need_to_update_cache = true;
+ }
}
if (bidi_it->scan_dir == -1)
/* If we are going backwards, the iterator state is already cached
@@ -2535,7 +2590,8 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
}
level = bidi_it->level_stack[bidi_it->stack_idx].level;
- if (bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */)
+ if (bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */
+ || bidi_isolate_fmt_char (type))
{
if (bidi_it->next_for_neutral.type == UNKNOWN_BT)
emacs_abort ();
@@ -2558,7 +2614,8 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
/* For L1 below, we need to know, for each WS character, whether
it belongs to a sequence of WS characters preceding a newline
or a TAB or a paragraph separator. */
- if (bidi_it->orig_type == NEUTRAL_WS
+ if ((bidi_it->orig_type == NEUTRAL_WS
+ || bidi_isolate_fmt_char (bidi_it->orig_type))
&& bidi_it->next_for_ws.type == UNKNOWN_BT)
{
int ch;
@@ -2579,6 +2636,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
bidi_it->w, fwp, &clen, &nc);
chtype = bidi_get_type (ch, NEUTRAL_DIR);
} while (chtype == NEUTRAL_WS || chtype == WEAK_BN
+ || bidi_isolate_fmt_char (chtype)
|| bidi_explicit_dir_char (ch)); /* L1/Retaining */
bidi_it->next_for_ws.type = chtype;
bidi_check_type (bidi_it->next_for_ws.type);
@@ -2607,9 +2665,9 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
level++;
}
- /* FIXME: Exempt explicit directional characters from the assignment
- below, and remove the PDF hack above. */
bidi_it->resolved_level = level;
+ if (need_to_update_cache)
+ bidi_cache_iterator_state (bidi_it, 1);
return level;
}
diff --git a/src/dispextern.h b/src/dispextern.h
index c823194bd6b..d61b2a388d5 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1915,7 +1915,6 @@ struct bidi_stack {
struct bidi_saved_info last_strong;
struct bidi_saved_info next_for_neutral;
struct bidi_saved_info prev_for_neutral;
- struct bidi_saved_info next_for_ws;
unsigned level : 7;
bool_bf isolate_status : 1;
unsigned override : 2;
--
2.39.5