--- /dev/null
+/* Low-level bidirectional buffer-scanning functions for GNU Emacs.
+ Copyright (C) 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+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.
+
+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. */
+
+/* A sequential implementation of the Unicode Bidirectional algorithm,
+ 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.
+
+ 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
+ returns its information in a special structure. The caller is then
+ expected to process this character for display or any other
+ purposes, and call bidi_get_next_char_visually for the next
+ character. See the comments in bidi_get_next_char_visually for
+ more details about its algorithm that finds the next visual-order
+ character by resolving their levels on the fly.
+
+ A note about references to UAX#9 rules: if the reference says
+ something like "X9/Retaining", it means that you need to refer to
+ rule X9 and to its modifications decribed in the "Implementation
+ Notes" section of UAX#9, under "Retaining Format Codes". */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+#include "lisp.h"
+#include "buffer.h"
+#include "character.h"
+#include "dispextern.h"
+
+static int bidi_initialized = 0;
+
+static Lisp_Object bidi_type_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 CHARSET_HEBREW 0x88
+#define CHARSET_ARABIC 0x87
+#define CHARSET_SYRIAC -1 /* these are undefined yet, -1 is invalid */
+#define CHARSET_THAANA -1
+
+/* FIXME: need to define wrappers for FETCH_CHAR etc. that return
+ BIDI_EOB when they hit ZV. */
+#define BIDI_EOB -1
+#define BIDI_BOB -2
+
+#ifdef TEST_STANDALONE
+/* Testing. */
+
+static unsigned char *input_buf;
+static size_t input_buf_size;
+
+int _fetch_multibyte_char_len, _c_c_;
+
+#undef FETCH_CHAR_ADVANCE
+#define FETCH_CHAR_ADVANCE(ch, cp, bp) \
+ do { \
+ ch = input_buf[cp]; \
+ (cp)++; \
+ (bp)++; \
+ if (ch == '\0') \
+ ch = BIDI_EOB; \
+ } while (0)
+
+#undef FETCH_CHAR
+#define FETCH_CHAR(n) ((_c_c_ = input_buf[n]) ? _c_c_ : BIDI_EOB)
+
+#undef CHAR_CHARSET
+#define CHAR_CHARSET(c) \
+ (((c) >= 128 || ((c) < 8 && (c)) || ((c) >= 'A' && (c) < 'X')) \
+ ? CHARSET_HEBREW \
+ : ((((c) >= 'X' && (c) <= 'Z') || ((c) >= '6' && (c) <= '9')) \
+ ? CHARSET_ARABIC \
+ : CHARSET_ASCII))
+
+#undef CHAR_TO_BYTE
+#define CHAR_TO_BYTE(pos) (pos)
+
+#define char_bytes(ch) 1
+
+#undef LRE_CHAR
+#undef LRO_CHAR
+#undef RLE_CHAR
+#undef RLO_CHAR
+#undef PDF_CHAR
+#undef RLM_CHAR
+#undef LRM_CHAR
+
+#define LRE_CHAR 1
+#define LRO_CHAR 2
+#define RLE_CHAR 3
+#define RLO_CHAR 4
+#define PDF_CHAR 5
+#define RLM_CHAR 6
+#define LRM_CHAR 7
+
+static const char *bidi_name[] =
+ {
+ "[???]", "[LRE]", "[LRO]", "[RLE]", "[RLO]", "[PDF]", "[RLM]", "[LRM]"
+ };
+
+#endif /* TEST_STANDALONE */
+
+/* Local data structures. (Look in dispextern.h for the rest.) */
+
+/* What we need to know about the current paragraph. */
+struct bidi_paragraph_info {
+ int start_bytepos; /* byte position where it begins */
+ 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,
+ NEUTRAL,
+ WEAK,
+ STRONG
+} bidi_category_t;
+
+int bidi_ignore_explicit_marks_for_paragraph_level = 1;
+
+bidi_dir_t bidi_overriding_paragraph_direction = NEUTRAL_DIR;
+
+#define ASCII_BIDI_TYPE_SET(STR, TYPE) \
+ do { \
+ unsigned char *p; \
+ for (p = (STR); *p; p++) \
+ CHAR_TABLE_SET (bidi_type_table, *p, (TYPE)); \
+ } while (0)
+
+static void
+bidi_initialize ()
+{
+ /* FIXME: This should come from the Unicode Database. */
+ struct {
+ int from, to;
+ bidi_type_t type;
+ } bidi_type[] =
+ { { 0x0000, 0x0008, WEAK_BN },
+ { 0x0009, 0x0000, NEUTRAL_S },
+ { 0x000A, 0x0000, NEUTRAL_B },
+ { 0x000B, 0x0000, NEUTRAL_S },
+ { 0x000C, 0x0000, NEUTRAL_WS },
+ { 0x000D, 0x0000, NEUTRAL_B },
+ { 0x000E, 0x001B, WEAK_BN },
+ { 0x001C, 0x001E, NEUTRAL_B },
+ { 0x001F, 0x0000, NEUTRAL_S },
+ { 0x0020, 0x0000, NEUTRAL_WS },
+ { 0x0021, 0x0022, NEUTRAL_ON },
+ { 0x0023, 0x0025, WEAK_ET },
+ { 0x0026, 0x002A, NEUTRAL_ON },
+ { 0x002B, 0x0000, WEAK_ET },
+ { 0x002C, 0x0000, WEAK_CS },
+ { 0x002D, 0x0000, WEAK_ET },
+ { 0x002E, 0x0000, WEAK_CS },
+ { 0x002F, 0x0000, WEAK_ES },
+ { 0x0030, 0x0039, WEAK_EN },
+ { 0x003A, 0x0000, WEAK_CS },
+ { 0x003B, 0x0040, NEUTRAL_ON },
+ { 0x005B, 0x0060, NEUTRAL_ON },
+ { 0x007B, 0x007E, NEUTRAL_ON },
+ { 0x007F, 0x0084, WEAK_BN },
+ { 0x0085, 0x0000, NEUTRAL_B },
+ { 0x0086, 0x009F, WEAK_BN },
+ { 0x00A0, 0x0000, WEAK_CS },
+ { 0x00A1, 0x0000, NEUTRAL_ON },
+ { 0x00A2, 0x00A5, WEAK_ET },
+ { 0x00A6, 0x00A9, NEUTRAL_ON },
+ { 0x00AB, 0x00AF, NEUTRAL_ON },
+ { 0x00B0, 0x00B1, WEAK_ET },
+ { 0x00B2, 0x00B3, WEAK_EN },
+ { 0x00B4, 0x0000, NEUTRAL_ON },
+ { 0x00B6, 0x00B8, NEUTRAL_ON },
+ { 0x00B9, 0x0000, WEAK_EN },
+ { 0x00BB, 0x00BF, NEUTRAL_ON },
+ { 0x00D7, 0x0000, NEUTRAL_ON },
+ { 0x00F7, 0x0000, NEUTRAL_ON },
+ { 0x02B9, 0x02BA, NEUTRAL_ON },
+ { 0x02C2, 0x02CF, NEUTRAL_ON },
+ { 0x02D2, 0x02DF, NEUTRAL_ON },
+ { 0x02E5, 0x02ED, NEUTRAL_ON },
+ { 0x0300, 0x036F, WEAK_NSM },
+ { 0x0374, 0x0375, NEUTRAL_ON },
+ { 0x037E, 0x0385, NEUTRAL_ON },
+ { 0x0387, 0x0000, NEUTRAL_ON },
+ { 0x03F6, 0x0000, NEUTRAL_ON },
+ { 0x0483, 0x0489, WEAK_NSM },
+ { 0x058A, 0x0000, NEUTRAL_ON },
+ { 0x0591, 0x05BD, WEAK_NSM },
+ { 0x05BE, 0x0000, STRONG_R },
+ { 0x05BF, 0x0000, WEAK_NSM },
+ { 0x05C0, 0x0000, STRONG_R },
+ { 0x05C1, 0x05C2, WEAK_NSM },
+ { 0x05C3, 0x0000, STRONG_R },
+ { 0x05C4, 0x0000, WEAK_NSM },
+ { 0x05D0, 0x05F4, STRONG_R },
+ { 0x060C, 0x0000, WEAK_CS },
+ { 0x061B, 0x064A, STRONG_AL },
+ { 0x064B, 0x0655, WEAK_NSM },
+ { 0x0660, 0x0669, WEAK_AN },
+ { 0x066A, 0x0000, WEAK_ET },
+ { 0x066B, 0x066C, WEAK_AN },
+ { 0x066D, 0x066F, STRONG_AL },
+ { 0x0670, 0x0000, WEAK_NSM },
+ { 0x0671, 0x06D5, STRONG_AL },
+ { 0x06D6, 0x06DC, WEAK_NSM },
+ { 0x06DD, 0x0000, STRONG_AL },
+ { 0x06DE, 0x06E4, WEAK_NSM },
+ { 0x06E5, 0x06E6, STRONG_AL },
+ { 0x06E7, 0x06E8, WEAK_NSM },
+ { 0x06E9, 0x0000, NEUTRAL_ON },
+ { 0x06EA, 0x06ED, WEAK_NSM },
+ { 0x06F0, 0x06F9, WEAK_EN },
+ { 0x06FA, 0x070D, STRONG_AL },
+ { 0x070F, 0x0000, WEAK_BN },
+ { 0x0710, 0x0000, STRONG_AL },
+ { 0x0711, 0x0000, WEAK_NSM },
+ { 0x0712, 0x072C, STRONG_AL },
+ { 0x0730, 0x074A, WEAK_NSM },
+ { 0x0780, 0x07A5, STRONG_AL },
+ { 0x07A6, 0x07B0, WEAK_NSM },
+ { 0x07B1, 0x0000, STRONG_AL },
+ { 0x0901, 0x0902, WEAK_NSM },
+ { 0x093C, 0x0000, WEAK_NSM },
+ { 0x0941, 0x0948, WEAK_NSM },
+ { 0x094D, 0x0000, WEAK_NSM },
+ { 0x0951, 0x0954, WEAK_NSM },
+ { 0x0962, 0x0963, WEAK_NSM },
+ { 0x0981, 0x0000, WEAK_NSM },
+ { 0x09BC, 0x0000, WEAK_NSM },
+ { 0x09C1, 0x09C4, WEAK_NSM },
+ { 0x09CD, 0x0000, WEAK_NSM },
+ { 0x09E2, 0x09E3, WEAK_NSM },
+ { 0x09F2, 0x09F3, WEAK_ET },
+ { 0x0A02, 0x0000, WEAK_NSM },
+ { 0x0A3C, 0x0000, WEAK_NSM },
+ { 0x0A41, 0x0A4D, WEAK_NSM },
+ { 0x0A70, 0x0A71, WEAK_NSM },
+ { 0x0A81, 0x0A82, WEAK_NSM },
+ { 0x0ABC, 0x0000, WEAK_NSM },
+ { 0x0AC1, 0x0AC8, WEAK_NSM },
+ { 0x0ACD, 0x0000, WEAK_NSM },
+ { 0x0B01, 0x0000, WEAK_NSM },
+ { 0x0B3C, 0x0000, WEAK_NSM },
+ { 0x0B3F, 0x0000, WEAK_NSM },
+ { 0x0B41, 0x0B43, WEAK_NSM },
+ { 0x0B4D, 0x0B56, WEAK_NSM },
+ { 0x0B82, 0x0000, WEAK_NSM },
+ { 0x0BC0, 0x0000, WEAK_NSM },
+ { 0x0BCD, 0x0000, WEAK_NSM },
+ { 0x0C3E, 0x0C40, WEAK_NSM },
+ { 0x0C46, 0x0C56, WEAK_NSM },
+ { 0x0CBF, 0x0000, WEAK_NSM },
+ { 0x0CC6, 0x0000, WEAK_NSM },
+ { 0x0CCC, 0x0CCD, WEAK_NSM },
+ { 0x0D41, 0x0D43, WEAK_NSM },
+ { 0x0D4D, 0x0000, WEAK_NSM },
+ { 0x0DCA, 0x0000, WEAK_NSM },
+ { 0x0DD2, 0x0DD6, WEAK_NSM },
+ { 0x0E31, 0x0000, WEAK_NSM },
+ { 0x0E34, 0x0E3A, WEAK_NSM },
+ { 0x0E3F, 0x0000, WEAK_ET },
+ { 0x0E47, 0x0E4E, WEAK_NSM },
+ { 0x0EB1, 0x0000, WEAK_NSM },
+ { 0x0EB4, 0x0EBC, WEAK_NSM },
+ { 0x0EC8, 0x0ECD, WEAK_NSM },
+ { 0x0F18, 0x0F19, WEAK_NSM },
+ { 0x0F35, 0x0000, WEAK_NSM },
+ { 0x0F37, 0x0000, WEAK_NSM },
+ { 0x0F39, 0x0000, WEAK_NSM },
+ { 0x0F3A, 0x0F3D, NEUTRAL_ON },
+ { 0x0F71, 0x0F7E, WEAK_NSM },
+ { 0x0F80, 0x0F84, WEAK_NSM },
+ { 0x0F86, 0x0F87, WEAK_NSM },
+ { 0x0F90, 0x0FBC, WEAK_NSM },
+ { 0x0FC6, 0x0000, WEAK_NSM },
+ { 0x102D, 0x1030, WEAK_NSM },
+ { 0x1032, 0x1037, WEAK_NSM },
+ { 0x1039, 0x0000, WEAK_NSM },
+ { 0x1058, 0x1059, WEAK_NSM },
+ { 0x1680, 0x0000, NEUTRAL_WS },
+ { 0x169B, 0x169C, NEUTRAL_ON },
+ { 0x1712, 0x1714, WEAK_NSM },
+ { 0x1732, 0x1734, WEAK_NSM },
+ { 0x1752, 0x1753, WEAK_NSM },
+ { 0x1772, 0x1773, WEAK_NSM },
+ { 0x17B7, 0x17BD, WEAK_NSM },
+ { 0x17C6, 0x0000, WEAK_NSM },
+ { 0x17C9, 0x17D3, WEAK_NSM },
+ { 0x17DB, 0x0000, WEAK_ET },
+ { 0x1800, 0x180A, NEUTRAL_ON },
+ { 0x180B, 0x180D, WEAK_NSM },
+ { 0x180E, 0x0000, WEAK_BN },
+ { 0x18A9, 0x0000, WEAK_NSM },
+ { 0x1FBD, 0x0000, NEUTRAL_ON },
+ { 0x1FBF, 0x1FC1, NEUTRAL_ON },
+ { 0x1FCD, 0x1FCF, NEUTRAL_ON },
+ { 0x1FDD, 0x1FDF, NEUTRAL_ON },
+ { 0x1FED, 0x1FEF, NEUTRAL_ON },
+ { 0x1FFD, 0x1FFE, NEUTRAL_ON },
+ { 0x2000, 0x200A, NEUTRAL_WS },
+ { 0x200B, 0x200D, WEAK_BN },
+ { 0x200F, 0x0000, STRONG_R },
+ { 0x2010, 0x2027, NEUTRAL_ON },
+ { 0x2028, 0x0000, NEUTRAL_WS },
+ { 0x2029, 0x0000, NEUTRAL_B },
+ { 0x202A, 0x0000, LRE },
+ { 0x202B, 0x0000, RLE },
+ { 0x202C, 0x0000, PDF },
+ { 0x202D, 0x0000, LRO },
+ { 0x202E, 0x0000, RLO },
+ { 0x202F, 0x0000, NEUTRAL_WS },
+ { 0x2030, 0x2034, WEAK_ET },
+ { 0x2035, 0x2057, NEUTRAL_ON },
+ { 0x205F, 0x0000, NEUTRAL_WS },
+ { 0x2060, 0x206F, WEAK_BN },
+ { 0x2070, 0x0000, WEAK_EN },
+ { 0x2074, 0x2079, WEAK_EN },
+ { 0x207A, 0x207B, WEAK_ET },
+ { 0x207C, 0x207E, NEUTRAL_ON },
+ { 0x2080, 0x2089, WEAK_EN },
+ { 0x208A, 0x208B, WEAK_ET },
+ { 0x208C, 0x208E, NEUTRAL_ON },
+ { 0x20A0, 0x20B1, WEAK_ET },
+ { 0x20D0, 0x20EA, WEAK_NSM },
+ { 0x2100, 0x2101, NEUTRAL_ON },
+ { 0x2103, 0x2106, NEUTRAL_ON },
+ { 0x2108, 0x2109, NEUTRAL_ON },
+ { 0x2114, 0x0000, NEUTRAL_ON },
+ { 0x2116, 0x2118, NEUTRAL_ON },
+ { 0x211E, 0x2123, NEUTRAL_ON },
+ { 0x2125, 0x0000, NEUTRAL_ON },
+ { 0x2127, 0x0000, NEUTRAL_ON },
+ { 0x2129, 0x0000, NEUTRAL_ON },
+ { 0x212E, 0x0000, WEAK_ET },
+ { 0x2132, 0x0000, NEUTRAL_ON },
+ { 0x213A, 0x0000, NEUTRAL_ON },
+ { 0x2140, 0x2144, NEUTRAL_ON },
+ { 0x214A, 0x215F, NEUTRAL_ON },
+ { 0x2190, 0x2211, NEUTRAL_ON },
+ { 0x2212, 0x2213, WEAK_ET },
+ { 0x2214, 0x2335, NEUTRAL_ON },
+ { 0x237B, 0x2394, NEUTRAL_ON },
+ { 0x2396, 0x244A, NEUTRAL_ON },
+ { 0x2460, 0x249B, WEAK_EN },
+ { 0x24EA, 0x0000, WEAK_EN },
+ { 0x24EB, 0x2FFB, NEUTRAL_ON },
+ { 0x3000, 0x0000, NEUTRAL_WS },
+ { 0x3001, 0x3004, NEUTRAL_ON },
+ { 0x3008, 0x3020, NEUTRAL_ON },
+ { 0x302A, 0x302F, WEAK_NSM },
+ { 0x3030, 0x0000, NEUTRAL_ON },
+ { 0x3036, 0x3037, NEUTRAL_ON },
+ { 0x303D, 0x303F, NEUTRAL_ON },
+ { 0x3099, 0x309A, WEAK_NSM },
+ { 0x309B, 0x309C, NEUTRAL_ON },
+ { 0x30A0, 0x0000, NEUTRAL_ON },
+ { 0x30FB, 0x0000, NEUTRAL_ON },
+ { 0x3251, 0x325F, NEUTRAL_ON },
+ { 0x32B1, 0x32BF, NEUTRAL_ON },
+ { 0xA490, 0xA4C6, NEUTRAL_ON },
+ { 0xFB1D, 0x0000, STRONG_R },
+ { 0xFB1E, 0x0000, WEAK_NSM },
+ { 0xFB1F, 0xFB28, STRONG_R },
+ { 0xFB29, 0x0000, WEAK_ET },
+ { 0xFB2A, 0xFB4F, STRONG_R },
+ { 0xFB50, 0xFD3D, STRONG_AL },
+ { 0xFD3E, 0xFD3F, NEUTRAL_ON },
+ { 0xFD50, 0xFDFC, STRONG_AL },
+ { 0xFE00, 0xFE23, WEAK_NSM },
+ { 0xFE30, 0xFE4F, NEUTRAL_ON },
+ { 0xFE50, 0x0000, WEAK_CS },
+ { 0xFE51, 0x0000, NEUTRAL_ON },
+ { 0xFE52, 0x0000, WEAK_CS },
+ { 0xFE54, 0x0000, NEUTRAL_ON },
+ { 0xFE55, 0x0000, WEAK_CS },
+ { 0xFE56, 0xFE5E, NEUTRAL_ON },
+ { 0xFE5F, 0x0000, WEAK_ET },
+ { 0xFE60, 0xFE61, NEUTRAL_ON },
+ { 0xFE62, 0xFE63, WEAK_ET },
+ { 0xFE64, 0xFE68, NEUTRAL_ON },
+ { 0xFE69, 0xFE6A, WEAK_ET },
+ { 0xFE6B, 0x0000, NEUTRAL_ON },
+ { 0xFE70, 0xFEFC, STRONG_AL },
+ { 0xFEFF, 0x0000, WEAK_BN },
+ { 0xFF01, 0xFF02, NEUTRAL_ON },
+ { 0xFF03, 0xFF05, WEAK_ET },
+ { 0xFF06, 0xFF0A, NEUTRAL_ON },
+ { 0xFF0B, 0x0000, WEAK_ET },
+ { 0xFF0C, 0x0000, WEAK_CS },
+ { 0xFF0D, 0x0000, WEAK_ET },
+ { 0xFF0E, 0x0000, WEAK_CS },
+ { 0xFF0F, 0x0000, WEAK_ES },
+ { 0xFF10, 0xFF19, WEAK_EN },
+ { 0xFF1A, 0x0000, WEAK_CS },
+ { 0xFF1B, 0xFF20, NEUTRAL_ON },
+ { 0xFF3B, 0xFF40, NEUTRAL_ON },
+ { 0xFF5B, 0xFF65, NEUTRAL_ON },
+ { 0xFFE0, 0xFFE1, WEAK_ET },
+ { 0xFFE2, 0xFFE4, NEUTRAL_ON },
+ { 0xFFE5, 0xFFE6, WEAK_ET },
+ { 0xFFE8, 0xFFEE, NEUTRAL_ON },
+ { 0xFFF9, 0xFFFB, WEAK_BN },
+ { 0xFFFC, 0xFFFD, NEUTRAL_ON },
+ { 0x1D167, 0x1D169, WEAK_NSM },
+ { 0x1D173, 0x1D17A, WEAK_BN },
+ { 0x1D17B, 0x1D182, WEAK_NSM },
+ { 0x1D185, 0x1D18B, WEAK_NSM },
+ { 0x1D1AA, 0x1D1AD, WEAK_NSM },
+ { 0x1D7CE, 0x1D7FF, WEAK_EN },
+ { 0xE0001, 0xE007F, WEAK_BN } };
+ int i;
+
+ bidi_type_table = Fmake_char_table (Qnil, make_number (STRONG_L));
+
+ 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_initialized = 1;
+}
+
+static int
+bidi_is_arabic_number (int ch)
+{
+#ifdef TEST_STANDALONE
+ return ch >= '6' && ch <= '9';
+#else
+ return 0; /* FIXME! */
+#endif
+}
+
+/* Return the bidi type of a character CH. */
+bidi_type_t
+bidi_get_type (int ch)
+{
+ return (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch));
+}
+
+/* Given a bidi TYPE of a character, return its category. */
+bidi_category_t
+bidi_get_category (bidi_type_t type)
+{
+ switch (type)
+ {
+ case UNKNOWN_BT:
+ return UNKNOWN_BC;
+ case STRONG_L:
+ case STRONG_R:
+ case STRONG_AL:
+ case LRE:
+ case LRO:
+ case RLE:
+ case RLO:
+ return STRONG;
+ case PDF: /* ??? really?? */
+ case WEAK_EN:
+ case WEAK_ES:
+ case WEAK_ET:
+ case WEAK_AN:
+ case WEAK_CS:
+ case WEAK_NSM:
+ case WEAK_BN:
+ return WEAK;
+ case NEUTRAL_B:
+ case NEUTRAL_S:
+ case NEUTRAL_WS:
+ case NEUTRAL_ON:
+ return NEUTRAL;
+ default:
+ abort ();
+ }
+}
+
+/* FIXME: exceedingly temporary! Should consult the Unicode database
+ of character properties. */
+int
+bidi_mirror_char (int c)
+{
+ static const char mirrored_pairs[] = "()<>[]{}";
+ const char *p = strchr (mirrored_pairs, c);
+
+ if (p)
+ {
+ size_t i = p - mirrored_pairs;
+
+ if ((i & 1) == 0)
+ return mirrored_pairs[i + 1];
+ else
+ return mirrored_pairs[i - 1];
+ }
+ return c;
+}
+
+/* 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
+bidi_copy_it (struct bidi_it *to, struct bidi_it *from)
+{
+ int i;
+
+ /* Copy everything except the level stack. */
+ memcpy (to, from, ((int)&((struct bidi_it *)0)->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 */
+ for (i = 1; i <= from->stack_idx; i++)
+ to->level_stack[i] = from->level_stack[i];
+}
+
+/* Caching the bidi iterator states. */
+
+static struct bidi_it bidi_cache[1000]; /* FIXME: make this dynamically allocated! */
+static int bidi_cache_idx;
+static int bidi_cache_last_idx;
+
+static inline void
+bidi_cache_reset (void)
+{
+ bidi_cache_idx = 0;
+ bidi_cache_last_idx = -1;
+}
+
+static inline void
+bidi_cache_fetch_state (int idx, struct bidi_it *bidi_it)
+{
+ int current_scan_dir = bidi_it->scan_dir;
+
+ if (idx < 0 || idx >= bidi_cache_idx)
+ abort ();
+
+ bidi_copy_it (bidi_it, &bidi_cache[idx]);
+ bidi_it->scan_dir = current_scan_dir;
+ bidi_cache_last_idx = idx;
+}
+
+/* Find a cached state with a given CHARPOS and resolved embedding
+ 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
+bidi_cache_search (int charpos, int level, int dir)
+{
+ int i, i_start;
+
+ if (bidi_cache_idx)
+ {
+ 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)
+ i_start = bidi_cache_last_idx;
+ else
+ {
+ dir = -1;
+ i_start = bidi_cache_idx - 1;
+ }
+
+ if (dir < 0)
+ {
+ /* Linear search for now; FIXME! */
+ for (i = i_start; i >= 0; i--)
+ if (bidi_cache[i].charpos == charpos
+ && (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
+ && (level == -1 || bidi_cache[i].resolved_level <= level))
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+/* 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,
+ given the cached levels like this:
+
+ 1122333442211
+ AB C
+
+ and assuming we are at the position cached at the slot marked with
+ 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
+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;
+ int incr = before ? 1 : 0;
+
+ if (!dir)
+ dir = -1;
+ else if (!incr)
+ i += dir;
+
+ if (dir < 0)
+ {
+ while (i >= incr)
+ {
+ if (bidi_cache[i - incr].resolved_level >= 0
+ && bidi_cache[i - incr].resolved_level < level)
+ return i;
+ i--;
+ }
+ }
+ else
+ {
+ while (i < bidi_cache_idx - incr)
+ {
+ if (bidi_cache[i + incr].resolved_level >= 0
+ && bidi_cache[i + incr].resolved_level < level)
+ return i;
+ i++;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static inline void
+bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
+{
+ int idx;
+
+ /* We should never cache on backward scans. */
+ if (bidi_it->scan_dir == -1)
+ abort ();
+ idx = bidi_cache_search (bidi_it->charpos, -1, 1);
+
+ if (idx < 0)
+ {
+ idx = bidi_cache_idx;
+ if (idx > sizeof (bidi_cache) / sizeof (bidi_cache[0]) - 1)
+ abort ();
+ bidi_copy_it (&bidi_cache[idx], bidi_it);
+ if (!resolved)
+ bidi_cache[idx].resolved_level = -1;
+ }
+ else
+ {
+ /* Copy only the members which could have changed, to avoid
+ costly copying of the entire struct. */
+ bidi_cache[idx].type = bidi_it->type;
+ bidi_cache[idx].orig_type = bidi_it->orig_type;
+ if (resolved)
+ bidi_cache[idx].resolved_level = bidi_it->resolved_level;
+ else
+ bidi_cache[idx].resolved_level = -1;
+ bidi_cache[idx].invalid_levels = bidi_it->invalid_levels;
+ bidi_cache[idx].invalid_rl_levels = bidi_it->invalid_rl_levels;
+ bidi_cache[idx].next_for_neutral = bidi_it->next_for_neutral;
+ bidi_cache[idx].next_for_ws = bidi_it->next_for_ws;
+ bidi_cache[idx].ignore_bn_limit = bidi_it->ignore_bn_limit;
+ }
+
+ bidi_cache_last_idx = idx;
+ if (idx >= bidi_cache_idx)
+ bidi_cache_idx = idx + 1;
+}
+
+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);
+
+ if (i >= 0)
+ {
+ bidi_dir_t current_scan_dir = bidi_it->scan_dir;
+
+ *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. */
+ bidi_it->scan_dir = current_scan_dir;
+ return bidi_it->type;
+ }
+
+ return UNKNOWN_BT;
+}
+
+static inline int
+bidi_peek_at_next_level (struct bidi_it *bidi_it)
+{
+ if (bidi_cache_idx == 0 || bidi_cache_last_idx == -1)
+ abort ();
+ return bidi_cache[bidi_cache_last_idx + bidi_it->scan_dir].resolved_level;
+}
+
+/* Return non-zero if buffer's byte position POS is the last character
+ of a paragraph. THIS_CH is the character preceding the one at POS in
+ the buffer. */
+int
+bidi_at_paragraph_end (int this_ch, int pos)
+{
+ int next_ch = FETCH_CHAR (pos);
+
+ /* FIXME: This should support all Unicode characters that can end a
+ paragraph. */
+ return (this_ch == '\n' && next_ch == '\n') || this_ch == BIDI_EOB;
+}
+
+/* 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 (level_before < level_after || !bidi_it->prev_was_pdf)
+ /* 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.orig_type =
+ bidi_it->last_strong.pristine_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.orig_type =
+ bidi_it->next_for_neutral.pristine_type = UNKNOWN_BT;
+ bidi_it->ignore_bn_limit = 0; /* meaning it's unknown */
+}
+
+void
+bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it)
+{
+ bidi_it->level_stack[0].level = 0;
+ if (dir == R2L)
+ bidi_it->level_stack[0].level = 1;
+ else if (dir == NEUTRAL_DIR) /* P2 */
+ {
+ bidi_type_t type;
+ int pos = bidi_it->charpos, bytepos = bidi_it->bytepos;
+ int ch;
+
+ if (pos < 0)
+ pos = bytepos = 0;
+ else if (bidi_it->ch != BIDI_EOB)
+ {
+ pos++;
+ bytepos += bidi_it->ch_len;
+ }
+
+ ch = FETCH_CHAR (bytepos);
+ pos++;
+ bytepos += CHAR_BYTES (ch);
+
+ /* FIXME: should actually go to where the paragraph begins and
+ start the loop below from there, since UAX#9 says to find the
+ first strong directional character in the paragraph. */
+
+ for (type = bidi_get_type (ch);
+ /* 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; should try
+ with and without that to see the effect. */
+ (bidi_get_category (type) != STRONG)
+ || (bidi_ignore_explicit_marks_for_paragraph_level
+ && (type == RLE || type == RLO
+ || type == LRE || type == LRO));
+ type = bidi_get_type (ch))
+ {
+ if (type == NEUTRAL_B || bidi_at_paragraph_end (ch, bytepos))
+ break;
+ FETCH_CHAR_ADVANCE (ch, pos, bytepos);
+ }
+ if (type == STRONG_R || type == STRONG_AL) /* P3 */
+ bidi_it->level_stack[0].level = 1;
+ }
+ bidi_it->scan_dir = 1; /* FIXME: do we need to have control on this? */
+ bidi_it->resolved_level = bidi_it->level_stack[0].level;
+ bidi_it->level_stack[0].override = NEUTRAL_DIR; /* X1 */
+ bidi_it->invalid_levels = 0;
+ bidi_it->invalid_rl_levels = -1;
+ bidi_it->new_paragraph = 0;
+ bidi_it->next_en_pos = -1;
+ bidi_it->next_for_ws.type = UNKNOWN_BT;
+ bidi_set_sor_type (bidi_it, bidi_it->level_stack[0].level, 0); /* X10 */
+
+ bidi_cache_reset ();
+}
+
+/* Do whatever UAX#9 clause X8 says should be done at paragraph's end,
+ and set the new paragraph flag in the iterator. */
+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;
+ bidi_it->new_paragraph = 1;
+}
+
+/* Initialize the bidi iterator from buffer position POS for paragraph
+ direction DIR. Return the embedding level at POS. */
+void
+bidi_init_it (int pos, bidi_dir_t dir, struct bidi_it *bidi_it)
+{
+ if (! bidi_initialized)
+ bidi_initialize ();
+ bidi_set_paragraph_end (bidi_it);
+ bidi_it->charpos = pos;
+ if (pos <= 0)
+ {
+ bidi_it->bytepos = bidi_it->charpos;
+ bidi_it->ch_len = 1; /* so that incrementing bytepos works */
+ }
+ else
+ {
+ bidi_it->bytepos = CHAR_TO_BYTE (pos);
+ bidi_it->ch_len
+ = MULTIBYTE_FORM_LENGTH (BYTE_POS_ADDR (bidi_it->bytepos),
+ MAX_MULTIBYTE_LENGTH);
+ }
+ bidi_it->ch = '\x1d'; /* FIXME: should be U+2029 */
+ bidi_it->type = NEUTRAL_B;
+ bidi_it->orig_type = UNKNOWN_BT;
+ bidi_it->pristine_type = UNKNOWN_BT;
+ bidi_it->prev_was_pdf = 0;
+ bidi_it->prev.type = bidi_it->prev.orig_type = UNKNOWN_BT;
+ bidi_it->last_strong.type = bidi_it->last_strong.orig_type =
+ bidi_it->last_strong.pristine_type = UNKNOWN_BT;
+ bidi_it->next_for_neutral.charpos = -1;
+ bidi_it->next_for_neutral.type =
+ bidi_it->next_for_neutral.orig_type =
+ bidi_it->next_for_neutral.pristine_type = UNKNOWN_BT;
+ bidi_it->prev_for_neutral.charpos = -1;
+ bidi_it->prev_for_neutral.type =
+ bidi_it->prev_for_neutral.orig_type =
+ bidi_it->prev_for_neutral.pristine_type = UNKNOWN_BT;
+ bidi_it->sor = L2R; /* FIXME: should it be user-selectable? */
+ bidi_paragraph_init (dir, bidi_it);
+}
+
+/* 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;
+ saved_info->orig_type = bidi_it->orig_type;
+ saved_info->pristine_type = bidi_it->pristine_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);
+}
+
+/* A helper function for bidi_resolve_explicit. It advances to the
+ next character in logical order and determines the new embedding
+ level and directional override, but does not take into account
+ empty embeddings. */
+static int
+bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
+{
+ int curchar;
+ bidi_type_t type;
+ int current_level;
+ int new_level;
+ bidi_dir_t override;
+
+ if (bidi_it->charpos < 0)
+ bidi_it->charpos = bidi_it->bytepos = 0;
+ else
+ {
+ bidi_it->charpos++;
+ bidi_it->bytepos += bidi_it->ch_len;
+ }
+
+ current_level = bidi_it->level_stack[bidi_it->stack_idx].level; /* X1 */
+ 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; */
+ curchar = FETCH_CHAR (bidi_it->bytepos);
+ bidi_it->ch = curchar;
+ bidi_it->ch_len = CHAR_BYTES (curchar);
+
+ type = bidi_get_type (curchar);
+ bidi_it->pristine_type = type;
+
+ if (type != PDF)
+ bidi_it->prev_was_pdf = 0;
+
+ bidi_it->orig_type = UNKNOWN_BT;
+
+ switch (type)
+ {
+ case RLE: /* X2 */
+ case RLO: /* X4 */
+ bidi_it->orig_type = type;
+ type = WEAK_BN; /* X9/Retaining */
+ if (bidi_it->ignore_bn_limit <= 0)
+ {
+ if (current_level <= BIDI_MAXLEVEL - 4)
+ {
+ /* Compute the least odd embedding level greater than
+ the current level. */
+ new_level = ((current_level + 1) & ~1) + 1;
+ if (bidi_it->orig_type == RLE)
+ override = NEUTRAL_DIR;
+ else
+ override = R2L;
+ if (current_level == BIDI_MAXLEVEL - 4)
+ bidi_it->invalid_rl_levels = 0;
+ bidi_push_embedding_level (bidi_it, new_level, override);
+ }
+ else
+ {
+ bidi_it->invalid_levels++;
+ /* See the commentary about invalid_rl_levels below. */
+ if (bidi_it->invalid_rl_levels < 0)
+ bidi_it->invalid_rl_levels = 0;
+ bidi_it->invalid_rl_levels++;
+ }
+ }
+ else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
+ || bidi_it->next_en_pos > bidi_it->charpos)
+ type = WEAK_EN;
+ break;
+ case LRE: /* X3 */
+ case LRO: /* X5 */
+ bidi_it->orig_type = type;
+ type = WEAK_BN; /* X9/Retaining */
+ if (bidi_it->ignore_bn_limit <= 0)
+ {
+ if (current_level <= BIDI_MAXLEVEL - 5)
+ {
+ /* Compute the least even embedding level greater than
+ the current level. */
+ new_level = ((current_level + 2) & ~1);
+ if (bidi_it->orig_type == LRE)
+ override = NEUTRAL_DIR;
+ else
+ override = L2R;
+ bidi_push_embedding_level (bidi_it, new_level, override);
+ }
+ else
+ {
+ bidi_it->invalid_levels++;
+ /* invalid_rl_levels counts invalid levels encountered
+ while the embedding level was already too high for
+ LRE/LRO, but not for RLE/RLO. That is because
+ there may be exactly one PDF which we should not
+ ignore even though invalid_levels is non-zero.
+ invalid_rl_levels helps to know what PDF is
+ that. */
+ if (bidi_it->invalid_rl_levels >= 0)
+ bidi_it->invalid_rl_levels++;
+ }
+ }
+ else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
+ || bidi_it->next_en_pos > bidi_it->charpos)
+ type = WEAK_EN;
+ break;
+ case PDF: /* X7 */
+ bidi_it->orig_type = type;
+ type = WEAK_BN; /* X9/Retaining */
+ if (bidi_it->ignore_bn_limit <= 0)
+ {
+ if (!bidi_it->invalid_rl_levels)
+ {
+ new_level = bidi_pop_embedding_level (bidi_it);
+ bidi_it->invalid_rl_levels = -1;
+ if (bidi_it->invalid_levels)
+ bidi_it->invalid_levels--;
+ /* else nothing: UAX#9 says to ignore invalid PDFs */
+ }
+ if (!bidi_it->invalid_levels)
+ new_level = bidi_pop_embedding_level (bidi_it);
+ else
+ {
+ bidi_it->invalid_levels--;
+ bidi_it->invalid_rl_levels--;
+ }
+ }
+ else if (bidi_it->prev.orig_type == WEAK_EN /* W5/Retaining */
+ || bidi_it->next_en_pos > bidi_it->charpos)
+ type = WEAK_EN;
+ break;
+ default:
+ /* Nothing. */
+ break;
+ }
+
+ bidi_it->type = type;
+
+ return new_level;
+}
+
+/* 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. */
+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);
+
+ if (prev_level < new_level
+ && bidi_it->type == WEAK_BN
+ && bidi_it->ignore_bn_limit == 0 /* only if not already known */
+ && bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
+ + bidi_it->ch_len)))
+ {
+ /* Avoid pushing and popping embedding levels if the level run
+ is empty, as this breaks level runs where it shouldn't.
+ UAX#9 removes all the explicit embedding and override codes,
+ so empty embeddings disappear without a trace. We need to
+ behave as if we did the same. */
+ struct bidi_it saved_it;
+ int level = prev_level;
+
+ bidi_copy_it (&saved_it, bidi_it);
+
+ while (bidi_explicit_dir_char (FETCH_CHAR (bidi_it->bytepos
+ + bidi_it->ch_len)))
+ {
+ level = bidi_resolve_explicit_1 (bidi_it);
+ }
+
+ if (level == prev_level) /* empty embedding */
+ saved_it.ignore_bn_limit = bidi_it->charpos + 1;
+ else /* this embedding is non-empty */
+ saved_it.ignore_bn_limit = -1;
+
+ bidi_copy_it (bidi_it, &saved_it);
+ if (bidi_it->ignore_bn_limit > 0)
+ {
+ /* We pushed a level, but we shouldn't have. Undo that. */
+ if (!bidi_it->invalid_rl_levels)
+ {
+ new_level = bidi_pop_embedding_level (bidi_it);
+ bidi_it->invalid_rl_levels = -1;
+ if (bidi_it->invalid_levels)
+ bidi_it->invalid_levels--;
+ }
+ if (!bidi_it->invalid_levels)
+ new_level = bidi_pop_embedding_level (bidi_it);
+ else
+ {
+ bidi_it->invalid_levels--;
+ bidi_it->invalid_rl_levels--;
+ }
+ }
+ }
+
+ /* For when the paragraph end is defined by anything other than a
+ special Unicode character (a.k.a. ``higher protocols''). */
+ if (bidi_it->type != NEUTRAL_B)
+ if (bidi_at_paragraph_end (bidi_it->ch,
+ bidi_it->bytepos + bidi_it->ch_len))
+ bidi_it->type = NEUTRAL_B;
+
+ if (bidi_it->type == NEUTRAL_B) /* X8 */
+ {
+ bidi_set_paragraph_end (bidi_it);
+ bidi_it->orig_type = bidi_it->type; /* needed below and in L1 */
+ }
+
+ return new_level;
+}
+
+/* Advance in the buffer, resolve weak types and return the type of
+ the next character after weak type resolution. */
+bidi_type_t
+bidi_resolve_weak (struct bidi_it *bidi_it)
+{
+ bidi_type_t type;
+ bidi_dir_t override;
+ int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
+ int new_level = bidi_resolve_explicit (bidi_it);
+ int next_char;
+ bidi_type_t type_of_next;
+ struct bidi_it saved_it;
+
+ type = bidi_it->type;
+ override = bidi_it->level_stack[bidi_it->stack_idx].override;
+
+ if (type == UNKNOWN_BT
+ || type == LRE
+ || type == LRO
+ || type == RLE
+ || type == RLO
+ || type == PDF)
+ abort ();
+
+ if (new_level != prev_level
+ || bidi_it->type == NEUTRAL_B)
+ {
+ /* We've got a new embedding level run, compute the directional
+ type of sor and initialize per-run variables (UAX#9, clause
+ X10). */
+ bidi_set_sor_type (bidi_it, prev_level, new_level);
+ }
+ else if (type == NEUTRAL_S || type == NEUTRAL_WS
+ || type == WEAK_BN || type == STRONG_AL)
+ bidi_it->orig_type = type; /* needed in L1 */
+
+ /* Level and directional override status are already recorded in
+ bidi_it, and do not need any change; see X6. */
+ if (override == R2L) /* X6 */
+ type = STRONG_R;
+ else if (override == L2R)
+ type = STRONG_L;
+ else if (type == STRONG_AL)
+ type = STRONG_R; /* W3 */
+ else 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 pristine_type of
+ the previous character. */
+ if (bidi_it->prev.type != UNKNOWN_BT)
+ type = bidi_it->prev.pristine_type;
+ else if (bidi_it->sor == R2L)
+ type = STRONG_R;
+ else if (bidi_it->sor == L2R)
+ type = STRONG_L;
+ else /* shouldn't happen! */
+ abort ();
+ if (type == WEAK_EN /* W2 after W1 */
+ && bidi_it->last_strong.orig_type == STRONG_AL)
+ type = WEAK_AN;
+ }
+ else if (type == WEAK_EN /* W2 */
+ && bidi_it->last_strong.orig_type == STRONG_AL)
+ type = WEAK_AN;
+ else if ((type == WEAK_ES
+ && (bidi_it->prev.orig_type == WEAK_EN /* W4 */
+ && (bidi_it->prev.pristine_type == WEAK_EN
+ || bidi_it->prev.pristine_type == WEAK_NSM))) /* aft W1 */
+ || (type == WEAK_CS
+ && ((bidi_it->prev.orig_type == WEAK_EN
+ && (bidi_it->prev.pristine_type == WEAK_EN /* W4 */
+ || bidi_it->prev.pristine_type == WEAK_NSM)) /* a/W1 */
+ || bidi_it->prev.orig_type == WEAK_AN))) /* W4 */
+ {
+ next_char = FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
+ type_of_next = bidi_get_type (next_char);
+
+ if (type_of_next == WEAK_BN
+ || bidi_explicit_dir_char (next_char))
+ {
+ 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;
+ bidi_copy_it (bidi_it, &saved_it);
+ }
+
+ /* If the next character is EN, but the last strong-type
+ character is AL, that next EN will be changed to AN when we
+ process it in W2 above. So in that case, this ES should not
+ be changed into EN. */
+ if (type == WEAK_ES
+ && type_of_next == WEAK_EN
+ && bidi_it->last_strong.orig_type != STRONG_AL)
+ type = WEAK_EN;
+ else if (type == WEAK_CS)
+ {
+ if (bidi_it->prev.orig_type == WEAK_AN
+ && (type_of_next == WEAK_AN
+ /* If the next character is EN, but the last
+ strong-type character is AL, EN will be later
+ changed to AN when we process it in W2 above. So
+ in that case, this ES should not be changed into
+ EN. */
+ || (type_of_next == WEAK_EN
+ && bidi_it->last_strong.orig_type == STRONG_AL)))
+ type = WEAK_AN;
+ else if (bidi_it->prev.orig_type == WEAK_EN
+ && type_of_next == WEAK_EN
+ && bidi_it->last_strong.orig_type != STRONG_AL)
+ type = WEAK_EN;
+ }
+ }
+ else if (type == WEAK_ET /* W5: ET with EN before or after it */
+ || type == WEAK_BN) /* W5/Retaining */
+ {
+ if (bidi_it->prev.orig_type == WEAK_EN /* ET/BN with EN before it */
+ || bidi_it->next_en_pos > bidi_it->charpos)
+ type = WEAK_EN;
+ /* W5: ET with EN after it. */
+ else
+ {
+ int en_pos = bidi_it->charpos + 1;
+
+ next_char = FETCH_CHAR (bidi_it->bytepos + bidi_it->ch_len);
+ type_of_next = bidi_get_type (next_char);
+
+ if (type_of_next == WEAK_ET
+ || type_of_next == WEAK_BN
+ || bidi_explicit_dir_char (next_char))
+ {
+ bidi_copy_it (&saved_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;
+ bidi_copy_it (bidi_it, &saved_it);
+ }
+ if (type_of_next == WEAK_EN)
+ {
+ /* If the last strong character is AL, the EN we've
+ found will become AN when we get to it (W2). */
+ if (bidi_it->last_strong.orig_type != STRONG_AL)
+ {
+ type = WEAK_EN;
+ /* Remember this EN position, to speed up processing
+ of the next ETs. */
+ bidi_it->next_en_pos = en_pos;
+ }
+ else if (type == WEAK_BN)
+ type = NEUTRAL_ON; /* W6/Retaining */
+ }
+ }
+ }
+
+ if (type == WEAK_ES || type == WEAK_ET || type == WEAK_CS /* W6 */
+ || (type == WEAK_BN && (bidi_it->prev.orig_type == WEAK_CS /* W6/Ret. */
+ || bidi_it->prev.orig_type == WEAK_ES
+ || bidi_it->prev.orig_type == WEAK_ET)))
+ type = NEUTRAL_ON;
+
+ /* Store the type we've got so far, before we clobber it with strong
+ types in W7 and while resolving neutral types. But leave alone
+ the original types that were recorded above, because we will need
+ them for the L1 clause. */
+ if (bidi_it->orig_type == UNKNOWN_BT)
+ bidi_it->orig_type = type;
+
+ if (type == WEAK_EN) /* W7 */
+ {
+ if ((bidi_it->last_strong.orig_type == STRONG_L)
+ || (bidi_it->last_strong.type == UNKNOWN_BT && bidi_it->sor == L2R))
+ type = STRONG_L;
+ }
+
+ bidi_it->type = type;
+ return type;
+}
+
+bidi_type_t
+bidi_resolve_neutral (struct bidi_it *bidi_it)
+{
+ int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
+ bidi_type_t type = bidi_resolve_weak (bidi_it);
+ int current_level = bidi_it->level_stack[bidi_it->stack_idx].level;
+
+ if (!(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))
+ abort ();
+
+ if (bidi_get_category (type) == NEUTRAL
+ || (type == WEAK_BN && prev_level == current_level))
+ {
+ if (bidi_it->next_for_neutral.type != UNKNOWN_BT)
+ type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
+ bidi_it->next_for_neutral.type,
+ current_level);
+ else
+ {
+ /* 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
+ supposedly general-purpose algorithms by looking at their
+ own implementations, and fail to consider other possible
+ implementations! */
+ struct bidi_it saved_it;
+ bidi_type_t next_type;
+
+ if (bidi_it->scan_dir == -1)
+ abort ();
+
+ bidi_copy_it (&saved_it, bidi_it);
+ /* Scan the text forward until we find the first non-neutral
+ 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 {
+ /* Record the info about the previous character, so that
+ it will be cached below with this state. */
+ if (bidi_it->orig_type != WEAK_BN /* W1/Retaining */
+ && bidi_it->type != WEAK_BN)
+ bidi_remember_char (&bidi_it->prev, bidi_it);
+ type = bidi_resolve_weak (bidi_it);
+ /* 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)
+ /* 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));
+
+ bidi_remember_char (&saved_it.next_for_neutral, bidi_it);
+
+ switch (type)
+ {
+ case STRONG_L:
+ case STRONG_R:
+ case STRONG_AL:
+ next_type = type;
+ break;
+ case WEAK_EN:
+ case WEAK_AN:
+ /* N1: ``European and Arabic numbers are treated as
+ though they were R.'' */
+ next_type = STRONG_R;
+ saved_it.next_for_neutral.type = STRONG_R;
+ break;
+ case WEAK_BN:
+ if (!bidi_explicit_dir_char (bidi_it->ch))
+ abort (); /* can't happen: BNs are skipped */
+ /* FALLTHROUGH */
+ case NEUTRAL_B:
+ /* Marched all the way to the end of this level run.
+ We need to use the eor type, whose information is
+ stored by bidi_set_sor_type in the prev_for_neutral
+ member. */
+ if (saved_it.type != WEAK_BN
+ || bidi_get_category (bidi_it->prev.orig_type) == NEUTRAL)
+ {
+ next_type = bidi_it->prev_for_neutral.type;
+ saved_it.next_for_neutral.type = next_type;
+ }
+ else
+ {
+ /* This is a BN which does not adjoin neutrals.
+ Leave its type alone. */
+ bidi_copy_it (bidi_it, &saved_it);
+ return bidi_it->type;
+ }
+ break;
+ default:
+ abort ();
+ }
+ type = bidi_resolve_neutral_1 (saved_it.prev_for_neutral.type,
+ next_type, current_level);
+ saved_it.type = type;
+ bidi_copy_it (bidi_it, &saved_it);
+ }
+ }
+ return type;
+}
+
+/* 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
+bidi_type_of_next_char (struct bidi_it *bidi_it)
+{
+ bidi_type_t type;
+
+ /* This should always be called during a forward scan. */
+ if (bidi_it->scan_dir != 1)
+ abort ();
+
+ /* 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
+ && bidi_it->ignore_bn_limit <= bidi_it->charpos)
+ || (bidi_it->ignore_bn_limit == -1
+ && !bidi_explicit_dir_char (bidi_it->ch)))
+ bidi_it->ignore_bn_limit = 0;
+
+ type = bidi_resolve_neutral (bidi_it);
+
+ return type;
+}
+
+/* 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. */
+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;
+
+ 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)
+ return bidi_it->resolved_level;
+
+ /* Record the info about the previous character. */
+ if (bidi_it->orig_type != WEAK_BN /* W1/Retaining */
+ && bidi_it->type != WEAK_BN)
+ bidi_remember_char (&bidi_it->prev, bidi_it);
+ if (bidi_it->orig_type == STRONG_R || bidi_it->orig_type == STRONG_L
+ || bidi_it->orig_type == STRONG_AL)
+ bidi_remember_char (&bidi_it->last_strong, bidi_it);
+ /* FIXME: it sounds like we don't need both prev and
+ prev_for_neutral members, but I'm leaving them both for now. */
+ if (bidi_it->type == STRONG_R || bidi_it->type == STRONG_L
+ || bidi_it->type == WEAK_EN || bidi_it->type == WEAK_AN)
+ bidi_remember_char (&bidi_it->prev_for_neutral, bidi_it);
+
+ /* If we overstepped the characters used for resolving neutrals
+ and whitespace, invalidate their info in the iterator. */
+ if (bidi_it->charpos >= bidi_it->next_for_neutral.charpos)
+ bidi_it->next_for_neutral.type = UNKNOWN_BT;
+ if (bidi_it->next_en_pos >= 0
+ && bidi_it->charpos >= bidi_it->next_en_pos)
+ bidi_it->next_en_pos = -1;
+ if (bidi_it->next_for_ws.type != UNKNOWN_BT
+ && bidi_it->charpos >= bidi_it->next_for_ws.charpos)
+ bidi_it->next_for_ws.type = UNKNOWN_BT;
+
+ /* This must be taken before we fill the iterator with the info
+ about the next char. If we scan backwards, the iterator
+ state must be already cached, so there's no need to know the
+ embedding level of the previous character, since we will be
+ returning to our caller shortly. */
+ prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
+ }
+ 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);
+ if (type != UNKNOWN_BT)
+ {
+ /* Don't lose the information for resolving neutrals! The
+ cached states could have been cached before their
+ next_for_neutral member was computed. If we are on our way
+ forward, we can simply take the info from the previous
+ state. */
+ if (bidi_it->scan_dir == 1
+ && bidi_it->next_for_neutral.type == UNKNOWN_BT)
+ bidi_it->next_for_neutral = next_for_neutral;
+
+ /* If resolved_level is -1, it means this state was cached
+ before it was completely resolved, so we cannot return
+ it. */
+ if (bidi_it->resolved_level != -1)
+ return bidi_it->resolved_level;
+ }
+ if (bidi_it->scan_dir == -1)
+ /* If we are going backwards, the iterator state is already cached
+ from previous scans, and should be fully resolved. */
+ abort ();
+
+ if (type == UNKNOWN_BT)
+ type = bidi_type_of_next_char (bidi_it);
+
+ if (type == NEUTRAL_B)
+ return bidi_it->resolved_level;
+
+ level = bidi_it->level_stack[bidi_it->stack_idx].level;
+ if ((bidi_get_category (type) == NEUTRAL /* && type != NEUTRAL_B */)
+ || (type == WEAK_BN && prev_level == level))
+ {
+ if (bidi_it->next_for_neutral.type == UNKNOWN_BT)
+ abort ();
+
+ /* If the cached state shows a neutral character, it was not
+ resolved by bidi_resolve_neutral, so do it now. */
+ type = bidi_resolve_neutral_1 (bidi_it->prev_for_neutral.type,
+ bidi_it->next_for_neutral.type,
+ level);
+ }
+
+ if (!(type == STRONG_R
+ || type == STRONG_L
+ || type == WEAK_BN
+ || type == WEAK_EN
+ || type == WEAK_AN))
+ abort ();
+ bidi_it->type = type;
+
+ /* For L1 below, we need to know, for each WS character, whether
+ it belongs to a sequence of WS characters preceeding a newline
+ or a TAB or a paragraph separator. */
+ if (bidi_it->pristine_type == NEUTRAL_WS
+ && bidi_it->next_for_ws.type == UNKNOWN_BT)
+ {
+ int ch;
+ int clen = bidi_it->ch_len;
+ int bpos = bidi_it->bytepos;
+ int cpos = bidi_it->charpos;
+ bidi_type_t chtype;
+
+ do {
+ /*_fetch_multibyte_char_len = 1;*/
+ ch = FETCH_CHAR (bpos + clen);
+ bpos += clen;
+ cpos++;
+ clen = CHAR_BYTES (ch);
+ if (ch == '\n' /* || ch == LINESEP_CHAR */)
+ chtype = NEUTRAL_B;
+ else
+ chtype = bidi_get_type (ch);
+ } while (chtype == NEUTRAL_WS || chtype == WEAK_BN
+ || bidi_explicit_dir_char (ch)); /* L1/Retaining */
+ bidi_it->next_for_ws.type = chtype;
+ bidi_it->next_for_ws.charpos = cpos;
+ bidi_it->next_for_ws.bytepos = bpos;
+ }
+
+ /* Resolve implicit levels, with a twist: PDFs get the embedding
+ level of the enbedding they terminate. See below for the
+ reason. */
+ if (bidi_it->pristine_type == PDF
+ /* Don't do this if this formatting code didn't change the
+ embedding level due to invalid or empty embeddings. */
+ && prev_level != level)
+ {
+ /* Don't look in UAX#9 for the reason for this: it's our own
+ private quirk. The reason is that we want the formatting
+ codes to be delivered so that they bracket the text of their
+ embedding. For example, given the text
+
+ {RLO}teST{PDF}
+
+ we want it to be displayed as
+
+ {RLO}STet{PDF}
+
+ not as
+
+ STet{RLO}{PDF}
+
+ which will result because we bump up the embedding level as
+ soon as we see the RLO and pop it as soon as we see the PDF,
+ so RLO itself has the same embedding level as "teST", and
+ thus would be normally delivered last, just before the PDF.
+ The switch below fiddles with the level of PDF so that this
+ ugly side effect does not happen.
+
+ (This is, of course, only important if the formatting codes
+ are actually displayed, but Emacs does display them if the
+ user wants to.) */
+ level = prev_level;
+ }
+ else if (bidi_it->pristine_type == NEUTRAL_B /* L1 */
+ || bidi_it->pristine_type == NEUTRAL_S
+ || bidi_it->ch == '\n' /* || bidi_it->ch == LINESEP_CHAR */
+ || (bidi_it->pristine_type == NEUTRAL_WS
+ && (bidi_it->next_for_ws.type == NEUTRAL_B
+ || bidi_it->next_for_ws.type == NEUTRAL_S)))
+ level = bidi_it->level_stack[0].level;
+ else if ((level & 1) == 0) /* I1 */
+ {
+ if (type == STRONG_R)
+ level++;
+ else if (type == WEAK_EN || type == WEAK_AN)
+ level += 2;
+ }
+ else /* I2 */
+ {
+ if (type == STRONG_L || type == WEAK_EN || type == WEAK_AN)
+ level++;
+ }
+
+ bidi_it->resolved_level = level;
+ return level;
+}
+
+/* Move to the other edge of a level given by LEVEL. If END_FLAG is
+ non-zero, we are at the end of a level, and we need to prepare to
+ resume the scan of the lower level.
+
+ 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.
+
+ 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
+ all the levels higher than it. In other words, given the levels
+ like this:
+
+ 11111112222222333333334443343222222111111112223322111
+ A B C
+
+ and assuming we are at point A scanning left to right, this
+ function moves to point C, whereas the UAX#9 ``level 2 run'' ends
+ at point B. */
+static void
+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;
+
+ /* Try the cache first. */
+ if ((idx = bidi_cache_find_level_change (level, dir, end_flag)) >= 0)
+ bidi_cache_fetch_state (idx, bidi_it);
+ else
+ {
+ int new_level;
+
+ if (end_flag)
+ abort (); /* if we are at end of level, its edges must be cached */
+
+ bidi_cache_iterator_state (bidi_it, 1);
+ do {
+ new_level = bidi_level_of_next_char (bidi_it);
+ bidi_cache_iterator_state (bidi_it, 1);
+ } while (new_level >= level);
+ }
+}
+
+void
+bidi_get_next_char_visually (struct bidi_it *bidi_it)
+{
+ int old_level, new_level, next_level;
+ struct bidi_it prev_bidi_it;
+
+ if (bidi_it->scan_dir == 0)
+ {
+ bidi_it->scan_dir = 1; /* default to logical order */
+ }
+
+ if (bidi_it->new_paragraph)
+ bidi_paragraph_init (bidi_overriding_paragraph_direction, bidi_it);
+ if (bidi_cache_idx == 0)
+ bidi_copy_it (&prev_bidi_it, bidi_it);
+
+ old_level = bidi_it->resolved_level;
+ new_level = bidi_level_of_next_char (bidi_it);
+ if (bidi_it->ch == BIDI_EOB)
+ return;
+
+ /* 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. */
+ if (new_level != old_level)
+ {
+ int ascending = new_level > old_level;
+ int level_to_search = ascending ? old_level + 1 : old_level;
+ int incr = ascending ? 1 : -1;
+ int expected_next_level = old_level + incr;
+
+ /* If we don't have anything cached yet, we need to cache the
+ previous character we've seen, since we'll need it to record
+ where to jump when the last non-base level is exhausted. */
+ if (bidi_cache_idx == 0)
+ bidi_cache_iterator_state (&prev_bidi_it, 1);
+ /* Jump (or walk) to the other edge of this level. */
+ bidi_find_other_level_edge (bidi_it, level_to_search, !ascending);
+ /* Switch scan direction and peek at the next character in the
+ new direction. */
+ bidi_it->scan_dir = -bidi_it->scan_dir;
+
+ /* The following loop handles the case where the resolved level
+ jumps by more than one. This is typical for numbers inside a
+ run of text with left-to-right embedding direction, but can
+ also happen in other situations. In those cases the decision
+ where to continue after a level change, and in what direction,
+ is tricky. For example, given a text like below:
+
+ abcdefgh
+ 11336622
+
+ (where the numbers below the text show the resolved levels),
+ the result of reordering according to UAX#9 should be this:
+
+ efdcghba
+
+ This is implemented by the loop below which flips direction
+ and jumps to the other edge of the level each time it finds
+ the new level not to be the expected one. The expected level
+ is always one more or one less than the previous one. */
+ next_level = bidi_peek_at_next_level (bidi_it);
+ while (next_level != expected_next_level)
+ {
+ expected_next_level += incr;
+ level_to_search += incr;
+ bidi_find_other_level_edge (bidi_it, level_to_search, !ascending);
+ bidi_it->scan_dir = -bidi_it->scan_dir;
+ next_level = bidi_peek_at_next_level (bidi_it);
+ }
+
+ /* Finally, deliver the next character in the new direction. */
+ next_level = bidi_level_of_next_char (bidi_it);
+ }
+
+ if (bidi_it->scan_dir == 1 && bidi_cache_idx)
+ {
+ /* 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_cache_reset ();
+ /* But as long as we are caching during forward scan, we must
+ cache each state, or else the cache integrity will be
+ compromised: it assumes cached states correspond to buffer
+ positions 1:1. */
+ else
+ bidi_cache_iterator_state (bidi_it, 1);
+ }
+}
+
+/* This is meant to be called from within the debugger, whenever you
+ wish to examine the cache contents. */
+void
+bidi_dump_cached_states (void)
+{
+ int i;
+ int ndigits = 1;
+
+ if (bidi_cache_idx == 0)
+ {
+ fprintf (stderr, "The cache is empty.\n");
+ return;
+ }
+ fprintf (stderr, "Total of %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)
+ ndigits++;
+ fputs ("ch ", stderr);
+ for (i = 0; i < bidi_cache_idx; i++)
+ fprintf (stderr, "%*c", ndigits, bidi_cache[i].ch);
+ fputs ("\n", stderr);
+ fputs ("lvl ", stderr);
+ for (i = 0; i < bidi_cache_idx; i++)
+ fprintf (stderr, "%*d", ndigits, bidi_cache[i].resolved_level);
+ fputs ("\n", stderr);
+ fputs ("pos ", stderr);
+ for (i = 0; i < bidi_cache_idx; i++)
+ fprintf (stderr, "%*d", ndigits, bidi_cache[i].charpos);
+ fputs ("\n", stderr);
+}
+
+#ifdef TEST_STANDALONE
+
+#include <sys/stat.h>
+#include <signal.h>
+
+static char display_line[80];
+static int simulate_display;
+static int incr = 1;
+
+void
+signal_catcher (int sig)
+{
+ if (simulate_display)
+ puts (display_line);
+ else
+ {
+ puts ("<");
+ fflush (stdout);
+ }
+ signal (sig, SIG_DFL);
+ raise (sig);
+}
+
+void
+put_line (char *p)
+{
+ if (simulate_display)
+ {
+ if (incr == -1)
+ {
+ if (p >= display_line)
+ memset (display_line, ' ', p - display_line + 1);
+ }
+ else
+ *p = '\0';
+ fputs (display_line, stdout);
+ }
+ fflush (stdout);
+}
+
+char *
+init_display_direction (bidi_dir_t default_dir, int base_level)
+{
+ char *p;
+
+ /* To which display margin should we flush the lines? */
+ switch (default_dir)
+ {
+ case NEUTRAL_DIR:
+ if ((base_level & 1) == 0)
+ {
+ p = display_line;
+ incr = 1;
+ }
+ else
+ {
+ p = display_line + sizeof (display_line) - 1;
+ *p-- = '\0';
+ incr = -1;
+ }
+ break;
+ case L2R:
+ p = display_line;
+ incr = 1;
+ break;
+ case R2L:
+ p = display_line + sizeof (display_line) - 1;
+ *p-- = '\0';
+ incr = -1;
+ break;
+ default:
+ abort ();
+ }
+
+ return p;
+}
+
+static char *
+continuation_line (char *p, int need)
+{
+ if (incr == -1)
+ {
+ if (p < display_line + need)
+ {
+ *p-- = '/';
+ put_line (p);
+ putc ('\n', stdout);
+ memset (display_line, '>', sizeof(display_line) - 1);
+ p = display_line + sizeof (display_line) - 1;
+ *p-- = '\0';
+ }
+ }
+ else
+ {
+ if (p > display_line + sizeof(display_line) - need - 2)
+ {
+ *p++ = '\\';
+ put_line (p);
+ putc ('\n', stdout);
+ memset (display_line, '<', sizeof(display_line) - 1);
+ p = display_line;
+ }
+ }
+
+ return p;
+}
+
+int main (int argc, char *argv[])
+{
+ bidi_dir_t default_dir = NEUTRAL_DIR;
+ char lots_of_equals[] = "\n===============================================================================\n";
+
+
+ if (argc > 1 && argv[1][0] == '-')
+ {
+ switch (argv[1][1])
+ {
+ case 'R':
+ default_dir = R2L;
+ simulate_display = 1;
+ ++argv;
+ break;
+ case 'L':
+ default_dir = L2R;
+ simulate_display = 1;
+ ++argv;
+ break;
+ case 'N':
+ simulate_display = 1;
+ ++argv;
+ break;
+ default:
+ break;
+ }
+ bidi_overriding_paragraph_direction = default_dir;
+ }
+
+ for (argv++; *argv; argv++)
+ {
+ FILE *in = fopen (*argv, "rb");
+ struct stat stat_buf;
+ struct bidi_it iterator;
+ size_t i;
+ char *p = display_line;
+ int base_level;
+ unsigned char *s, *d, *s_end;
+
+ if (!in || stat (*argv, &stat_buf))
+ {
+ perror (*argv);
+ continue;
+ }
+
+ if (stat_buf.st_size > input_buf_size)
+ {
+ input_buf = realloc (input_buf, stat_buf.st_size + 1);
+ if (!input_buf)
+ {
+ perror ("realloc input buffer");
+ continue;
+ }
+ input_buf_size = stat_buf.st_size;
+ }
+ if (fread (input_buf, 1, stat_buf.st_size, in) != stat_buf.st_size)
+ {
+ perror ("reading input");
+ continue;
+ }
+ input_buf[stat_buf.st_size] = '\0';
+ for (d = s = input_buf, s_end = s + stat_buf.st_size - 1; *s; s++)
+ {
+ if (*s != '\r' || s >= s_end || s[1] != '\n')
+ *d++ = *s;
+ }
+ stat_buf.st_size = d - input_buf;
+ input_buf[stat_buf.st_size] = '\0';
+
+ /* Done with administrivia, now for some real work... */
+ signal (SIGABRT, signal_catcher);
+ signal (SIGINT, signal_catcher);
+ bidi_init_it (-1, default_dir, &iterator);
+ if (simulate_display)
+ {
+ p = init_display_direction (default_dir,
+ iterator.level_stack[0].level);
+ }
+
+ memset (display_line, incr == -1 ? '>' : '<', sizeof (display_line) - 1);
+ display_line[sizeof (display_line) - 1] = '\0';
+ base_level = iterator.level_stack[0].level;
+
+ for (i = 0; i <= stat_buf.st_size; i++)
+ {
+ int c;
+
+ bidi_get_next_char_visually (&iterator);
+ c = iterator.ch;
+
+ if (c == '\n' || c == BIDI_EOB)
+ {
+ if (simulate_display)
+ {
+ put_line (p);
+ /* FIXME: if -R or -L, need to init paragraph here. */
+ }
+ if (c == BIDI_EOB)
+ break;
+ putc (c, stdout);
+ }
+ else if (c >= LRE_CHAR && c <= LRM_CHAR)
+ {
+ if (simulate_display)
+ {
+ p = continuation_line (p, 5);
+ if (incr == -1)
+ {
+ memcpy (p - 4, bidi_name[c], 5);
+ p -= 5;
+ }
+ else
+ {
+ memcpy (p, bidi_name[c], 5);
+ p += 5;
+ }
+ }
+ else
+ fputs (bidi_name[c], stdout);
+ }
+ else if (c < ' ')
+ {
+ if (simulate_display)
+ {
+ p = continuation_line (p, 2);
+ if (incr == -1)
+ {
+ *p-- = '@' + c;
+ *p-- = '^';
+ }
+ else
+ {
+ *p++ = '^';
+ *p++ = '@' + c;
+ }
+ }
+ else
+ printf ("^%c", (c | 0x40));
+ }
+ else
+ {
+ int c1 = (iterator.type == STRONG_R) ? bidi_mirror_char (c) : c;
+
+ if (simulate_display)
+ {
+ p = continuation_line (p, 1);
+ *p = c1;
+ p += incr;
+ }
+ else
+ putc (c1, stdout);
+ }
+
+ if (iterator.ch == '\n')
+ {
+ if (base_level != iterator.level_stack[0].level)
+ base_level = iterator.level_stack[0].level;
+ p = init_display_direction (default_dir, base_level);
+ memset (display_line, incr == -1 ? '>' : '<',
+ sizeof (display_line) - 1);
+ }
+ }
+ fputs (lots_of_equals, stdout);
+ fclose (in);
+ }
+ return 0;
+}
+#endif
projects / emacs.git / commitdiff