2 * This file is part of DisOrder
3 * Copyright (C) 2007, 2009, 2013 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /** @file lib/unicode.c
19 * @brief Unicode support functions
21 * Here by UTF-8 and UTF-8 we mean the encoding forms of those names (not the
22 * encoding schemes). The primary encoding form is UTF-32 but convenience
23 * wrappers using UTF-8 are provided for a number of functions.
25 * The idea is that all the strings that hit the database will be in a
26 * particular normalization form, and for the search and tags database
27 * in case-folded form, so they can be naively compared within the
30 * As the code stands this guarantee is not well met!
35 * - @ref utf32iterator
47 /** @defgroup utf32props Unicode Code Point Properties */
50 static const struct unidata *utf32__unidata_hard(uint32_t c);
52 /** @brief Find definition of code point @p c
54 * @return Pointer to @ref unidata structure for @p c
56 * @p c can be any 32-bit value, a sensible value will be returned regardless.
57 * The returned pointer is NOT guaranteed to be unique to @p c.
59 static inline const struct unidata *utf32__unidata(uint32_t c) {
60 /* The bottom half of the table contains almost everything of interest
61 * and we can just return the right thing straight away */
62 if(c < UNICODE_BREAK_START)
63 return &unidata[c / UNICODE_MODULUS][c % UNICODE_MODULUS];
65 return utf32__unidata_hard(c);
68 /** @brief Find definition of code point @p c
70 * @return Pointer to @ref unidata structure for @p c
72 * @p c can be any 32-bit value, a sensible value will be returned regardless.
73 * The returned pointer is NOT guaranteed to be unique to @p c.
75 * Don't use this function (although it will work fine) - use utf32__unidata()
78 static const struct unidata *utf32__unidata_hard(uint32_t c) {
79 if(c < UNICODE_BREAK_START)
80 return &unidata[c / UNICODE_MODULUS][c % UNICODE_MODULUS];
81 /* Within the break everything is unassigned */
82 if(c < UNICODE_BREAK_END)
83 return utf32__unidata(0xFFFF); /* guaranteed to be Cn */
84 /* Planes 15 and 16 are (mostly) private use */
85 if((c >= 0xF0000 && c <= 0xFFFFD)
86 || (c >= 0x100000 && c <= 0x10FFFD))
87 return utf32__unidata(0xE000); /* first Co code point */
88 /* Everything else above the break top is unassigned */
89 if(c >= UNICODE_BREAK_TOP)
90 return utf32__unidata(0xFFFF); /* guaranteed to be Cn */
91 /* Currently the rest is language tags and variation selectors */
92 c -= (UNICODE_BREAK_END - UNICODE_BREAK_START);
93 return &unidata[c / UNICODE_MODULUS][c % UNICODE_MODULUS];
96 /** @brief Return the combining class of @p c
98 * @return Combining class of @p c
100 * @p c can be any 32-bit value, a sensible value will be returned regardless.
102 static inline int utf32__combining_class(uint32_t c) {
103 return utf32__unidata(c)->ccc;
106 /** @brief Return the combining class of @p c
107 * @param c Code point
108 * @return Combining class of @p c
110 * @p c can be any 32-bit value, a sensible value will be returned regardless.
112 int utf32_combining_class(uint32_t c) {
113 return utf32__combining_class(c);
116 /** @brief Return the General_Category value for @p c
117 * @param c Code point
118 * @return General_Category property value
120 * @p c can be any 32-bit value, a sensible value will be returned regardless.
122 static inline enum unicode_General_Category utf32__general_category(uint32_t c) {
123 return utf32__unidata(c)->general_category;
126 /** @brief Determine Grapheme_Break property
127 * @param c Code point
128 * @return Grapheme_Break property value of @p c
130 * @p c can be any 32-bit value, a sensible value will be returned regardless.
132 static inline enum unicode_Grapheme_Break utf32__grapheme_break(uint32_t c) {
133 return utf32__unidata(c)->grapheme_break;
136 /** @brief Determine Word_Break property
137 * @param c Code point
138 * @return Word_Break property value of @p c
140 * @p c can be any 32-bit value, a sensible value will be returned regardless.
142 static inline enum unicode_Word_Break utf32__word_break(uint32_t c) {
143 return utf32__unidata(c)->word_break;
146 /** @brief Determine Sentence_Break property
147 * @param c Code point
148 * @return Word_Break property value of @p c
150 * @p c can be any 32-bit value, a sensible value will be returned regardless.
152 static inline enum unicode_Sentence_Break utf32__sentence_break(uint32_t c) {
153 return utf32__unidata(c)->sentence_break;
156 /** @brief Return true if @p c is ignorable for boundary specifications
157 * @param wb Word break property value
158 * @return non-0 if @p wb is unicode_Word_Break_Extend or unicode_Word_Break_Format
160 static inline int utf32__boundary_ignorable(enum unicode_Word_Break wb) {
161 return (wb == unicode_Word_Break_Extend
162 || wb == unicode_Word_Break_Format);
165 /** @brief Return the canonical decomposition of @p c
166 * @param c Code point
167 * @return 0-terminated canonical decomposition, or 0
169 static inline const uint32_t *utf32__decomposition_canon(uint32_t c) {
170 const struct unidata *const data = utf32__unidata(c);
171 const uint32_t *const decomp = data->decomp;
173 if(decomp && !(data->flags & unicode_compatibility_decomposition))
179 /** @brief Return the compatibility decomposition of @p c
180 * @param c Code point
181 * @return 0-terminated decomposition, or 0
183 static inline const uint32_t *utf32__decomposition_compat(uint32_t c) {
184 return utf32__unidata(c)->decomp;
188 /** @defgroup utftransform Functions that transform between different Unicode encoding forms */
191 /** @brief Convert UTF-32 to UTF-8
192 * @param s Source string
193 * @param ns Length of source string in code points
194 * @param ndp Where to store length of destination string (or NULL)
195 * @return Newly allocated destination string or NULL on error
197 * If the UTF-32 is not valid then NULL is returned. A UTF-32 code point is
199 * - it codes for a UTF-16 surrogate
200 * - it codes for a value outside the unicode code space
202 * The return value is always 0-terminated. The value returned via @p *ndp
203 * does not include the terminator.
205 char *utf32_to_utf8(const uint32_t *s, size_t ns, size_t *ndp) {
213 dynstr_append(&d, c);
214 else if(c < 0x0800) {
215 dynstr_append(&d, 0xC0 | (c >> 6));
216 dynstr_append(&d, 0x80 | (c & 0x3F));
217 } else if(c < 0x10000) {
218 if(c >= 0xD800 && c <= 0xDFFF)
220 dynstr_append(&d, 0xE0 | (c >> 12));
221 dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
222 dynstr_append(&d, 0x80 | (c & 0x3F));
223 } else if(c < 0x110000) {
224 dynstr_append(&d, 0xF0 | (c >> 18));
225 dynstr_append(&d, 0x80 | ((c >> 12) & 0x3F));
226 dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
227 dynstr_append(&d, 0x80 | (c & 0x3F));
232 dynstr_terminate(&d);
241 /** @brief Convert UTF-8 to UTF-32
242 * @param s Source string
243 * @param ns Length of source string in code points
244 * @param ndp Where to store length of destination string (or NULL)
245 * @return Newly allocated destination string or NULL on error
247 * The return value is always 0-terminated. The value returned via @p *ndp
248 * does not include the terminator.
250 * If the UTF-8 is not valid then NULL is returned. A UTF-8 sequence
251 * for a code point is invalid if:
252 * - it is not the shortest possible sequence for the code point
253 * - it codes for a UTF-16 surrogate
254 * - it codes for a value outside the unicode code space
256 uint32_t *utf8_to_utf32(const char *s, size_t ns, size_t *ndp) {
257 struct dynstr_ucs4 d;
259 const uint8_t *ss = (const uint8_t *)s;
262 dynstr_ucs4_init(&d);
264 const struct unicode_utf8_row *const r = &unicode_utf8_valid[*ss];
271 if(ss[1] < r->min2 || ss[1] > r->max2)
276 if(ss[1] < r->min2 || ss[1] > r->max2)
281 if(ss[1] < r->min2 || ss[1] > r->max2)
290 for(n = 1; n < r->count; ++n) {
291 if(ss[n] < 0x80 || ss[n] > 0xBF)
293 c32 = (c32 << 6) | (ss[n] & 0x3F);
295 dynstr_ucs4_append(&d, c32);
299 dynstr_ucs4_terminate(&d);
308 /** @brief Convert UTF-16 to UTF-8
309 * @param s Source string
310 * @param ns Length of source string in code points
311 * @param ndp Where to store length of destination string (or NULL)
312 * @return Newly allocated destination string or NULL on error
314 * If the UTF-16 is not valid then NULL is returned. A UTF-16 sequence t is
315 * invalid if it contains an incomplete surrogate.
317 * The return value is always 0-terminated. The value returned via @p *ndp
318 * does not include the terminator.
320 char *utf16_to_utf8(const uint16_t *s, size_t ns, size_t *ndp) {
328 if(c >= 0xD800 && c <= 0xDBFF) {
329 if(ns && *s >= 0xDC00 && c <= 0xDFFF)
330 c = ((c - 0xD800) << 10) + (*s++ - 0xDC00) + 0x10000;
333 } else if(c >= 0xDC00 && c <= 0xDFFF)
336 dynstr_append(&d, c);
337 else if(c < 0x0800) {
338 dynstr_append(&d, 0xC0 | (c >> 6));
339 dynstr_append(&d, 0x80 | (c & 0x3F));
340 } else if(c < 0x10000) {
341 if(c >= 0xD800 && c <= 0xDFFF)
343 dynstr_append(&d, 0xE0 | (c >> 12));
344 dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
345 dynstr_append(&d, 0x80 | (c & 0x3F));
346 } else if(c < 0x110000) {
347 dynstr_append(&d, 0xF0 | (c >> 18));
348 dynstr_append(&d, 0x80 | ((c >> 12) & 0x3F));
349 dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
350 dynstr_append(&d, 0x80 | (c & 0x3F));
354 dynstr_terminate(&d);
363 /** @brief Convert UTF-8 to UTF-16
364 * @param s Source string
365 * @param ns Length of source string in code points
366 * @param ndp Where to store length of destination string (or NULL)
367 * @return Newly allocated destination string or NULL on error
369 * The return value is always 0-terminated. The value returned via @p *ndp
370 * does not include the terminator.
372 * If the UTF-8 is not valid then NULL is returned. A UTF-8 sequence
373 * for a code point is invalid if:
374 * - it is not the shortest possible sequence for the code point
375 * - it codes for a UTF-16 surrogate
376 * - it codes for a value outside the unicode code space
378 uint16_t *utf8_to_utf16(const char *s, size_t ns, size_t *ndp) {
379 struct dynstr_utf16 d;
381 const uint8_t *ss = (const uint8_t *)s;
384 dynstr_utf16_init(&d);
386 const struct unicode_utf8_row *const r = &unicode_utf8_valid[*ss];
393 if(ss[1] < r->min2 || ss[1] > r->max2)
398 if(ss[1] < r->min2 || ss[1] > r->max2)
403 if(ss[1] < r->min2 || ss[1] > r->max2)
412 for(n = 1; n < r->count; ++n) {
413 if(ss[n] < 0x80 || ss[n] > 0xBF)
415 c32 = (c32 << 6) | (ss[n] & 0x3F);
419 dynstr_utf16_append(&d, 0xD800 + (c32 >> 10));
420 dynstr_utf16_append(&d, 0xDC00 + (c32 & 0x03FF));
422 dynstr_utf16_append(&d, c32);
426 dynstr_utf16_terminate(&d);
435 /** @brief Test whether [s,s+ns) is valid UTF-8
436 * @param s Start of string
437 * @param ns Length of string
438 * @return non-0 if @p s is valid UTF-8, 0 if it is not valid
440 * This function is intended to be much faster than calling utf8_to_utf32() and
441 * throwing away the result.
443 int utf8_valid(const char *s, size_t ns) {
444 const uint8_t *ss = (const uint8_t *)s;
446 const struct unicode_utf8_row *const r = &unicode_utf8_valid[*ss];
452 if(ss[1] < r->min2 || ss[1] > r->max2)
456 if(ss[1] < r->min2 || ss[1] > r->max2)
458 if(ss[2] < 0x80 || ss[2] > 0xBF)
462 if(ss[1] < r->min2 || ss[1] > r->max2)
464 if(ss[2] < 0x80 || ss[2] > 0xBF)
466 if(ss[3] < 0x80 || ss[3] > 0xBF)
481 /** @defgroup utf32iterator UTF-32 string iterators */
484 struct utf32_iterator_data {
485 /** @brief Start of string */
488 /** @brief Length of string */
491 /** @brief Current position */
494 /** @brief Last two non-ignorable characters or (uint32_t)-1
496 * last[1] is the non-Extend/Format character just before position @p n;
497 * last[0] is the one just before that.
499 * Exception 1: if there is no such non-Extend/Format character then an
500 * Extend/Format character is accepted instead.
502 * Exception 2: if there is no such character even taking that into account
503 * the value is (uint32_t)-1.
507 /** @brief Tailoring for Word_Break */
508 unicode_property_tailor *word_break;
511 /** @brief Initialize an internal private iterator
513 * @param s Start of string
514 * @param ns Length of string
515 * @param n Absolute position
517 static void utf32__iterator_init(utf32_iterator it,
518 const uint32_t *s, size_t ns, size_t n) {
522 it->last[0] = it->last[1] = -1;
524 utf32_iterator_set(it, n);
527 /** @brief Create a new iterator pointing at the start of a string
528 * @param s Start of string
529 * @param ns Length of string
530 * @return New iterator
532 utf32_iterator utf32_iterator_new(const uint32_t *s, size_t ns) {
533 utf32_iterator it = xmalloc(sizeof *it);
534 utf32__iterator_init(it, s, ns, 0);
538 /** @brief Tailor this iterator's interpretation of the Word_Break property.
540 * @param pt Property tailor function or NULL
542 * After calling this the iterator will call @p pt to determine the Word_Break
543 * property of each code point. If it returns -1 the default value will be
544 * used otherwise the returned value will be used.
546 * @p pt can be NULL to revert to the default value of the property.
548 * It is safe to call this function at any time; the iterator's internal state
549 * will be reset to suit the new tailoring.
551 void utf32_iterator_tailor_word_break(utf32_iterator it,
552 unicode_property_tailor *pt) {
554 utf32_iterator_set(it, it->n);
557 static inline enum unicode_Word_Break utf32__iterator_word_break(utf32_iterator it,
560 return utf32__word_break(c);
562 const int t = it->word_break(c);
565 return utf32__word_break(c);
571 /** @brief Destroy an iterator
574 void utf32_iterator_destroy(utf32_iterator it) {
578 /** @brief Find the current position of an interator
581 size_t utf32_iterator_where(utf32_iterator it) {
585 /** @brief Set an iterator's absolute position
587 * @param n Absolute position
588 * @return 0 on success, non-0 on error
590 * It is an error to position the iterator outside the string (but acceptable
591 * to point it at the hypothetical post-final character). If an invalid value
592 * of @p n is specified then the iterator is not changed.
594 * This function works by backing up and then advancing to reconstruct the
595 * iterator's internal state for position @p n. The worst case will be O(n)
596 * time complexity (with a worse constant factor that utf32_iterator_advance())
597 * but the typical case is essentially constant-time.
599 int utf32_iterator_set(utf32_iterator it, size_t n) {
600 /* We can't just jump to position @p n; the @p last[] values will be wrong.
601 * What we need is to jump a bit behind @p n and then advance forward,
602 * updating @p last[] along the way. How far back? We need to cross two
603 * non-ignorable code points as we advance forwards, so we'd better pass two
604 * such characters on the way back (if such are available).
608 if(n > it->ns) /* range check */
610 /* Walk backwards skipping ignorable code points */
613 && (utf32__boundary_ignorable(utf32__iterator_word_break(it,
616 /* Either m=0 or s[m-1] is not ignorable */
619 /* s[m] is our first non-ignorable code; look for a second in the same
622 && (utf32__boundary_ignorable(utf32__iterator_word_break(it,
625 /* Either m=0 or s[m-1] is not ignorable */
629 it->last[0] = it->last[1] = -1;
631 return utf32_iterator_advance(it, n - m);
634 /** @brief Advance an iterator
636 * @param count Number of code points to advance by
637 * @return 0 on success, non-0 on error
639 * It is an error to advance an iterator beyond the hypothetical post-final
640 * character of the string. If an invalid value of @p n is specified then the
641 * iterator is not changed.
643 * This function has O(n) time complexity: it works by advancing naively
644 * forwards through the string.
646 int utf32_iterator_advance(utf32_iterator it, size_t count) {
647 if(count <= it->ns - it->n) {
649 const uint32_t c = it->s[it->n];
650 const enum unicode_Word_Break wb = utf32__iterator_word_break(it, c);
651 if(it->last[1] == (uint32_t)-1
652 || !utf32__boundary_ignorable(wb)) {
653 it->last[0] = it->last[1];
664 /** @brief Find the current code point
666 * @return Current code point or 0
668 * If the iterator points at the hypothetical post-final character of the
669 * string then 0 is returned. NB that this doesn't mean that there aren't any
670 * 0 code points inside the string!
672 uint32_t utf32_iterator_code(utf32_iterator it) {
679 /** @brief Test for a grapheme boundary
681 * @return Non-0 if pointing just after a grapheme boundary, otherwise 0
683 * This function identifies default grapheme cluster boundaries as described in
684 * UAX #29 s3. It returns non-0 if @p it points at the code point just after a
685 * grapheme cluster boundary (including the hypothetical code point just after
686 * the end of the string).
688 int utf32_iterator_grapheme_boundary(utf32_iterator it) {
689 uint32_t before, after;
690 enum unicode_Grapheme_Break gbbefore, gbafter;
692 if(it->n == 0 || it->n == it->ns)
694 /* Now we know that s[n-1] and s[n] are safe to inspect */
696 before = it->s[it->n-1];
697 after = it->s[it->n];
698 if(before == 0x000D && after == 0x000A)
700 gbbefore = utf32__grapheme_break(before);
701 gbafter = utf32__grapheme_break(after);
703 if(gbbefore == unicode_Grapheme_Break_Control
708 if(gbafter == unicode_Grapheme_Break_Control
713 if(gbbefore == unicode_Grapheme_Break_L
714 && (gbafter == unicode_Grapheme_Break_L
715 || gbafter == unicode_Grapheme_Break_V
716 || gbafter == unicode_Grapheme_Break_LV
717 || gbafter == unicode_Grapheme_Break_LVT))
720 if((gbbefore == unicode_Grapheme_Break_LV
721 || gbbefore == unicode_Grapheme_Break_V)
722 && (gbafter == unicode_Grapheme_Break_V
723 || gbafter == unicode_Grapheme_Break_T))
726 if((gbbefore == unicode_Grapheme_Break_LVT
727 || gbbefore == unicode_Grapheme_Break_T)
728 && gbafter == unicode_Grapheme_Break_T)
731 if(gbafter == unicode_Grapheme_Break_Extend)
734 if(gbafter == unicode_Grapheme_Break_SpacingMark)
737 if(gbbefore == unicode_Grapheme_Break_Prepend)
744 /** @brief Test for a word boundary
746 * @return Non-0 if pointing just after a word boundary, otherwise 0
748 * This function identifies default word boundaries as described in UAX #29 s4.
749 * It returns non-0 if @p it points at the code point just after a word
750 * boundary (including the hypothetical code point just after the end of the
751 * string) and 0 otherwise.
753 int utf32_iterator_word_boundary(utf32_iterator it) {
754 uint32_t before, after;
755 enum unicode_Word_Break wbtwobefore, wbbefore, wbafter, wbtwoafter;
759 if(it->n == 0 || it->n == it->ns)
761 before = it->s[it->n-1];
762 after = it->s[it->n];
764 if(before == 0x000D && after == 0x000A)
767 if(utf32__iterator_word_break(it, before) == unicode_Word_Break_Newline
772 if(utf32__iterator_word_break(it, after) == unicode_Word_Break_Newline
777 /* (!Sep) x (Extend|Format) as in UAX #29 s6.2 */
778 if(utf32__sentence_break(before) != unicode_Sentence_Break_Sep
779 && utf32__boundary_ignorable(utf32__iterator_word_break(it, after)))
781 /* Gather the property values we'll need for the rest of the test taking the
782 * s6.2 changes into account */
783 /* First we look at the code points after the proposed boundary */
784 nn = it->n; /* <it->ns */
785 wbafter = utf32__iterator_word_break(it, it->s[nn++]);
786 if(!utf32__boundary_ignorable(wbafter)) {
787 /* X (Extend|Format)* -> X */
789 && utf32__boundary_ignorable(utf32__iterator_word_break(it,
793 /* It's possible now that nn=ns */
795 wbtwoafter = utf32__iterator_word_break(it, it->s[nn]);
797 wbtwoafter = unicode_Word_Break_Other;
799 /* We've already recorded the non-ignorable code points before the proposed
801 wbbefore = utf32__iterator_word_break(it, it->last[1]);
802 wbtwobefore = utf32__iterator_word_break(it, it->last[0]);
805 if(wbbefore == unicode_Word_Break_ALetter
806 && wbafter == unicode_Word_Break_ALetter)
809 if(wbbefore == unicode_Word_Break_ALetter
810 && (wbafter == unicode_Word_Break_MidLetter
811 || wbafter == unicode_Word_Break_MidNumLet)
812 && wbtwoafter == unicode_Word_Break_ALetter)
815 if(wbtwobefore == unicode_Word_Break_ALetter
816 && (wbbefore == unicode_Word_Break_MidLetter
817 || wbbefore == unicode_Word_Break_MidNumLet)
818 && wbafter == unicode_Word_Break_ALetter)
821 if(wbbefore == unicode_Word_Break_Numeric
822 && wbafter == unicode_Word_Break_Numeric)
825 if(wbbefore == unicode_Word_Break_ALetter
826 && wbafter == unicode_Word_Break_Numeric)
829 if(wbbefore == unicode_Word_Break_Numeric
830 && wbafter == unicode_Word_Break_ALetter)
833 if(wbtwobefore == unicode_Word_Break_Numeric
834 && (wbbefore == unicode_Word_Break_MidNum
835 || wbbefore == unicode_Word_Break_MidNumLet)
836 && wbafter == unicode_Word_Break_Numeric)
839 if(wbbefore == unicode_Word_Break_Numeric
840 && (wbafter == unicode_Word_Break_MidNum
841 || wbafter == unicode_Word_Break_MidNumLet)
842 && wbtwoafter == unicode_Word_Break_Numeric)
845 if(wbbefore == unicode_Word_Break_Katakana
846 && wbafter == unicode_Word_Break_Katakana)
849 if((wbbefore == unicode_Word_Break_ALetter
850 || wbbefore == unicode_Word_Break_Numeric
851 || wbbefore == unicode_Word_Break_Katakana
852 || wbbefore == unicode_Word_Break_ExtendNumLet)
853 && wbafter == unicode_Word_Break_ExtendNumLet)
856 if(wbbefore == unicode_Word_Break_ExtendNumLet
857 && (wbafter == unicode_Word_Break_ALetter
858 || wbafter == unicode_Word_Break_Numeric
859 || wbafter == unicode_Word_Break_Katakana))
866 /** @defgroup utf32 Functions that operate on UTF-32 strings */
869 /** @brief Return the length of a 0-terminated UTF-32 string
870 * @param s Pointer to 0-terminated string
871 * @return Length of string in code points (excluding terminator)
873 * Unlike the conversion functions no validity checking is done on the string.
875 size_t utf32_len(const uint32_t *s) {
876 const uint32_t *t = s;
880 return (size_t)(t - s);
883 /** @brief Stably sort [s,s+ns) into descending order of combining class
884 * @param s Start of array
885 * @param ns Number of elements, must be at least 1
886 * @param buffer Buffer of at least @p ns elements
888 static void utf32__sort_ccc(uint32_t *s, size_t ns, uint32_t *buffer) {
889 uint32_t *a, *b, *bp;
893 case 1: /* 1-element array is always sorted */
895 case 2: /* 2-element arrays are trivial to sort */
896 if(utf32__combining_class(s[0]) > utf32__combining_class(s[1])) {
903 /* Partition the array */
908 /* Sort the two halves of the array */
909 utf32__sort_ccc(a, na, buffer);
910 utf32__sort_ccc(b, nb, buffer);
911 /* Merge them back into one, via the buffer */
913 while(na > 0 && nb > 0) {
914 /* We want ascending order of combining class (hence <)
915 * and we want stability within combining classes (hence <=)
917 if(utf32__combining_class(*a) <= utf32__combining_class(*b)) {
933 memcpy(s, buffer, ns * sizeof(uint32_t));
938 /** @brief Put combining characters into canonical order
939 * @param s Pointer to UTF-32 string
940 * @param ns Length of @p s
941 * @return 0 on success, non-0 on error
943 * @p s is modified in-place. See Unicode 5.0 s3.11 for details of the
946 * Currently we only support a maximum of 1024 combining characters after each
947 * base character. If this limit is exceeded then a non-0 value is returned.
949 static int utf32__canonical_ordering(uint32_t *s, size_t ns) {
951 uint32_t buffer[1024];
953 /* The ordering amounts to a stable sort of each contiguous group of
954 * characters with non-0 combining class. */
956 /* Skip non-combining characters */
957 if(utf32__combining_class(*s) == 0) {
962 /* We must now have at least one combining character; see how many
964 for(nc = 1; nc < ns && utf32__combining_class(s[nc]) != 0; ++nc)
969 utf32__sort_ccc(s, nc, buffer);
976 /* Magic numbers from UAX #15 s16 */
984 #define NCount (VCount * TCount)
985 #define SCount (LCount * NCount)
987 /** @brief Guts of the decomposition lookup functions */
988 #define utf32__decompose_one_generic(WHICH) do { \
989 const uint32_t *dc = utf32__decomposition_##WHICH(c); \
991 /* Found a canonical decomposition in the table */ \
993 utf32__decompose_one_##WHICH(d, *dc++); \
994 } else if(c >= SBase && c < SBase + SCount) { \
995 /* Mechanically decomposable Hangul syllable (UAX #15 s16) */ \
996 const uint32_t SIndex = c - SBase; \
997 const uint32_t L = LBase + SIndex / NCount; \
998 const uint32_t V = VBase + (SIndex % NCount) / TCount; \
999 const uint32_t T = TBase + SIndex % TCount; \
1000 dynstr_ucs4_append(d, L); \
1001 dynstr_ucs4_append(d, V); \
1003 dynstr_ucs4_append(d, T); \
1005 /* Equal to own canonical decomposition */ \
1006 dynstr_ucs4_append(d, c); \
1009 /** @brief Recursively compute the canonical decomposition of @p c
1010 * @param d Dynamic string to store decomposition in
1011 * @param c Code point to decompose (must be a valid!)
1012 * @return 0 on success, non-0 on error
1014 static void utf32__decompose_one_canon(struct dynstr_ucs4 *d, uint32_t c) {
1015 utf32__decompose_one_generic(canon);
1018 /** @brief Recursively compute the compatibility decomposition of @p c
1019 * @param d Dynamic string to store decomposition in
1020 * @param c Code point to decompose (must be a valid!)
1021 * @return 0 on success, non-0 on error
1023 static void utf32__decompose_one_compat(struct dynstr_ucs4 *d, uint32_t c) {
1024 utf32__decompose_one_generic(compat);
1027 /** @brief Magic utf32__compositions() return value for Hangul Choseong */
1028 static const uint32_t utf32__hangul_L[1];
1030 /** @brief Return the list of compositions that @p c starts
1031 * @param c Starter code point
1032 * @return Composition list or NULL
1034 * For Hangul leading (Choseong) jamo we return the special value
1035 * utf32__hangul_L. These code points are not listed as the targets of
1036 * canonical decompositions (make-unidata checks) so there is no confusion with
1037 * real decompositions here.
1039 static const uint32_t *utf32__compositions(uint32_t c) {
1040 const uint32_t *compositions = utf32__unidata(c)->composed;
1043 return compositions;
1044 /* Special-casing for Hangul */
1045 switch(utf32__grapheme_break(c)) {
1048 case unicode_Grapheme_Break_L:
1049 return utf32__hangul_L;
1053 /** @brief Composition step
1054 * @param s Start of string
1055 * @param ns Length of string
1056 * @return New length of string
1058 * This is called from utf32__decompose_generic() to compose the result string
1061 static size_t utf32__compose(uint32_t *s, size_t ns) {
1062 const uint32_t *compositions;
1063 uint32_t *start = s, *t = s, *tt, cc;
1066 uint32_t starter = *s++;
1067 int block_starters = 0;
1069 /* We don't attempt to compose the following things:
1070 * - final characters whatever kind they are
1071 * - non-starter characters
1072 * - starters that don't take part in a canonical decomposition mapping
1075 || utf32__combining_class(starter)
1076 || !(compositions = utf32__compositions(starter))) {
1080 if(compositions != utf32__hangul_L) {
1081 /* Where we'll put the eventual starter */
1084 /* See if we can find composition of starter+*s */
1085 const uint32_t cchar = *s, *cp = compositions;
1086 while((cc = *cp++)) {
1087 const uint32_t *decomp = utf32__decomposition_canon(cc);
1088 /* We know decomp[0] == starter */
1089 if(decomp[1] == cchar)
1093 /* Found a composition: cc decomposes to starter,*s */
1095 compositions = utf32__compositions(starter);
1099 /* No composition found. */
1100 const int class = utf32__combining_class(*s);
1102 /* Transfer the uncomposable combining character to the output */
1105 /* All the combining characters of the same class of the
1106 * uncomposable character are blocked by it, but there may be
1107 * others of higher class later. We eat the uncomposable and
1108 * blocked characters and go back round the loop for that higher
1110 while(ns > 0 && utf32__combining_class(*s) == class) {
1114 /* Block any subsequent starters */
1117 /* The uncombinable character is itself a starter, so we don't
1118 * transfer it to the output but instead go back round the main
1123 /* Keep going while there are still characters and the starter takes
1124 * part in some composition */
1125 } while(ns > 0 && compositions
1126 && (!block_starters || utf32__combining_class(*s)));
1127 /* Store any remaining combining characters */
1128 while(ns > 0 && utf32__combining_class(*s)) {
1132 /* Store the resulting starter */
1135 /* Special-casing for Hangul
1137 * If there are combining characters between the L and the V then they
1138 * will block the V and so no composition happens. Similarly combining
1139 * characters between V and T will block the T and so we only get as far
1142 if(utf32__grapheme_break(*s) == unicode_Grapheme_Break_V) {
1143 const uint32_t V = *s++;
1144 const uint32_t LIndex = starter - LBase;
1145 const uint32_t VIndex = V - VBase;
1149 && utf32__grapheme_break(*s) == unicode_Grapheme_Break_T) {
1150 /* We have an L V T sequence */
1151 const uint32_t T = *s++;
1157 /* Compose to LVT or LV as appropriate */
1158 starter = (LIndex * VCount + VIndex) * TCount + TIndex + SBase;
1159 } /* else we only have L or LV and no V or T */
1161 /* There could be some combining characters that belong to the V or T.
1162 * These will be treated as non-starter characters at the top of the loop
1163 * and thuss transferred to the output. */
1169 /** @brief Guts of the composition and decomposition functions
1170 * @param WHICH @c canon or @c compat to choose decomposition
1171 * @param COMPOSE @c 0 or @c 1 to compose
1173 #define utf32__decompose_generic(WHICH, COMPOSE) do { \
1174 struct dynstr_ucs4 d; \
1177 dynstr_ucs4_init(&d); \
1180 if((c >= 0xD800 && c <= 0xDFFF) || c > 0x10FFFF) \
1182 utf32__decompose_one_##WHICH(&d, c); \
1185 if(utf32__canonical_ordering(d.vec, d.nvec)) \
1188 d.nvec = utf32__compose(d.vec, d.nvec); \
1189 dynstr_ucs4_terminate(&d); \
1198 /** @brief Canonically decompose @p [s,s+ns)
1199 * @param s Pointer to string
1200 * @param ns Length of string
1201 * @param ndp Where to store length of result
1202 * @return Pointer to result string, or NULL on error
1204 * Computes NFD (Normalization Form D) of the string at @p s. This implies
1205 * performing all canonical decompositions and then normalizing the order of
1206 * combining characters.
1208 * Returns NULL if the string is not valid for either of the following reasons:
1209 * - it codes for a UTF-16 surrogate
1210 * - it codes for a value outside the unicode code space
1213 * - utf32_decompose_compat()
1214 * - utf32_compose_canon()
1216 uint32_t *utf32_decompose_canon(const uint32_t *s, size_t ns, size_t *ndp) {
1217 utf32__decompose_generic(canon, 0);
1220 /** @brief Compatibility decompose @p [s,s+ns)
1221 * @param s Pointer to string
1222 * @param ns Length of string
1223 * @param ndp Where to store length of result
1224 * @return Pointer to result string, or NULL on error
1226 * Computes NFKD (Normalization Form KD) of the string at @p s. This implies
1227 * performing all canonical and compatibility decompositions and then
1228 * normalizing the order of combining characters.
1230 * Returns NULL if the string is not valid for either of the following reasons:
1231 * - it codes for a UTF-16 surrogate
1232 * - it codes for a value outside the unicode code space
1235 * - utf32_decompose_canon()
1236 * - utf32_compose_compat()
1238 uint32_t *utf32_decompose_compat(const uint32_t *s, size_t ns, size_t *ndp) {
1239 utf32__decompose_generic(compat, 0);
1242 /** @brief Canonically compose @p [s,s+ns)
1243 * @param s Pointer to string
1244 * @param ns Length of string
1245 * @param ndp Where to store length of result
1246 * @return Pointer to result string, or NULL on error
1248 * Computes NFC (Normalization Form C) of the string at @p s. This implies
1249 * performing all canonical decompositions, normalizing the order of combining
1250 * characters and then composing all unblocked primary compositables.
1252 * Returns NULL if the string is not valid for either of the following reasons:
1253 * - it codes for a UTF-16 surrogate
1254 * - it codes for a value outside the unicode code space
1257 * - utf32_compose_compat()
1258 * - utf32_decompose_canon()
1260 uint32_t *utf32_compose_canon(const uint32_t *s, size_t ns, size_t *ndp) {
1261 utf32__decompose_generic(canon, 1);
1264 /** @brief Compatibility compose @p [s,s+ns)
1265 * @param s Pointer to string
1266 * @param ns Length of string
1267 * @param ndp Where to store length of result
1268 * @return Pointer to result string, or NULL on error
1270 * Computes NFKC (Normalization Form KC) of the string at @p s. This implies
1271 * performing all canonical and compatibility decompositions, normalizing the
1272 * order of combining characters and then composing all unblocked primary
1275 * Returns NULL if the string is not valid for either of the following reasons:
1276 * - it codes for a UTF-16 surrogate
1277 * - it codes for a value outside the unicode code space
1280 * - utf32_compose_canon()
1281 * - utf32_decompose_compat()
1283 uint32_t *utf32_compose_compat(const uint32_t *s, size_t ns, size_t *ndp) {
1284 utf32__decompose_generic(compat, 1);
1287 /** @brief Single-character case-fold and decompose operation */
1288 #define utf32__casefold_one(WHICH) do { \
1289 const uint32_t *cf = utf32__unidata(c)->casefold; \
1291 /* Found a case-fold mapping in the table */ \
1293 utf32__decompose_one_##WHICH(&d, *cf++); \
1295 utf32__decompose_one_##WHICH(&d, c); \
1298 /** @brief Case-fold @p [s,s+ns)
1299 * @param s Pointer to string
1300 * @param ns Length of string
1301 * @param ndp Where to store length of result
1302 * @return Pointer to result string, or NULL on error
1304 * Case-fold the string at @p s according to full default case-folding rules
1305 * (s3.13) for caseless matching. The result will be in NFD.
1307 * Returns NULL if the string is not valid for either of the following reasons:
1308 * - it codes for a UTF-16 surrogate
1309 * - it codes for a value outside the unicode code space
1311 uint32_t *utf32_casefold_canon(const uint32_t *s, size_t ns, size_t *ndp) {
1312 struct dynstr_ucs4 d;
1317 /* If the canonical decomposition of the string includes any combining
1318 * character that case-folds to a non-combining character then we must
1319 * normalize before we fold. In Unicode 5.0.0 this means 0345 COMBINING
1320 * GREEK YPOGEGRAMMENI in its decomposition and the various characters that
1321 * canonically decompose to it. */
1322 for(n = 0; n < ns; ++n)
1323 if(utf32__unidata(s[n])->flags & unicode_normalize_before_casefold)
1326 /* We need a preliminary decomposition */
1327 if(!(ss = utf32_decompose_canon(s, ns, &ns)))
1331 dynstr_ucs4_init(&d);
1334 if((c >= 0xD800 && c <= 0xDFFF) || c > 0x10FFFF)
1336 utf32__casefold_one(canon);
1339 if(utf32__canonical_ordering(d.vec, d.nvec))
1341 dynstr_ucs4_terminate(&d);
1351 /** @brief Compatibility case-fold @p [s,s+ns)
1352 * @param s Pointer to string
1353 * @param ns Length of string
1354 * @param ndp Where to store length of result
1355 * @return Pointer to result string, or NULL on error
1357 * Case-fold the string at @p s according to full default case-folding rules
1358 * (s3.13) for compatibility caseless matching. The result will be in NFKD.
1360 * Returns NULL if the string is not valid for either of the following reasons:
1361 * - it codes for a UTF-16 surrogate
1362 * - it codes for a value outside the unicode code space
1364 uint32_t *utf32_casefold_compat(const uint32_t *s, size_t ns, size_t *ndp) {
1365 struct dynstr_ucs4 d;
1370 for(n = 0; n < ns; ++n)
1371 if(utf32__unidata(s[n])->flags & unicode_normalize_before_casefold)
1374 /* We need a preliminary _canonical_ decomposition */
1375 if(!(ss = utf32_decompose_canon(s, ns, &ns)))
1379 /* This computes NFKD(toCaseFold(s)) */
1380 #define compat_casefold_middle() do { \
1381 dynstr_ucs4_init(&d); \
1384 if((c >= 0xD800 && c <= 0xDFFF) || c > 0x10FFFF) \
1386 utf32__casefold_one(compat); \
1389 if(utf32__canonical_ordering(d.vec, d.nvec)) \
1392 /* Do the inner (NFKD o toCaseFold) */
1393 compat_casefold_middle();
1394 /* We can do away with the NFD'd copy of the input now */
1398 /* Do the outer (NFKD o toCaseFold) */
1399 compat_casefold_middle();
1401 dynstr_ucs4_terminate(&d);
1411 /** @brief Order a pair of UTF-32 strings
1412 * @param a First 0-terminated string
1413 * @param b Second 0-terminated string
1414 * @return -1, 0 or 1 for a less than, equal to or greater than b
1416 * "Comparable to strcmp() at its best."
1418 int utf32_cmp(const uint32_t *a, const uint32_t *b) {
1419 while(*a && *b && *a == *b) {
1423 return *a < *b ? -1 : (*a > *b ? 1 : 0);
1426 /** @brief Identify a grapheme cluster boundary
1427 * @param s Start of string (must be NFD)
1428 * @param ns Length of string
1429 * @param n Index within string (in [0,ns].)
1430 * @return 1 at a grapheme cluster boundary, 0 otherwise
1432 * This function identifies default grapheme cluster boundaries as described in
1433 * UAX #29 s3. It returns non-0 if @p n points at the code point just after a
1434 * grapheme cluster boundary (including the hypothetical code point just after
1435 * the end of the string).
1437 * This function uses utf32_iterator_set() internally; see that function for
1438 * remarks on performance.
1440 int utf32_is_grapheme_boundary(const uint32_t *s, size_t ns, size_t n) {
1441 struct utf32_iterator_data it[1];
1443 utf32__iterator_init(it, s, ns, n);
1444 return utf32_iterator_grapheme_boundary(it);
1447 /** @brief Identify a word boundary
1448 * @param s Start of string (must be NFD)
1449 * @param ns Length of string
1450 * @param n Index within string (in [0,ns].)
1451 * @return 1 at a word boundary, 0 otherwise
1453 * This function identifies default word boundaries as described in UAX #29 s4.
1454 * It returns non-0 if @p n points at the code point just after a word boundary
1455 * (including the hypothetical code point just after the end of the string).
1457 * This function uses utf32_iterator_set() internally; see that function for
1458 * remarks on performance.
1460 int utf32_is_word_boundary(const uint32_t *s, size_t ns, size_t n) {
1461 struct utf32_iterator_data it[1];
1463 utf32__iterator_init(it, s, ns, n);
1464 return utf32_iterator_word_boundary(it);
1467 /** @brief Split [s,ns) into multiple words
1468 * @param s Pointer to start of string
1469 * @param ns Length of string
1470 * @param nwp Where to store word count, or NULL
1471 * @param wbreak Word_Break property tailor, or NULL
1472 * @return Pointer to array of pointers to words
1474 * The returned array is terminated by a NULL pointer and individual
1475 * strings are 0-terminated.
1477 uint32_t **utf32_word_split(const uint32_t *s, size_t ns, size_t *nwp,
1478 unicode_property_tailor *wbreak) {
1479 struct utf32_iterator_data it[1];
1480 size_t b1 = 0, b2 = 0 ,i;
1482 struct vector32 v32[1];
1486 utf32__iterator_init(it, s, ns, 0);
1487 it->word_break = wbreak;
1488 /* Work our way through the string stopping at each word break. */
1490 if(utf32_iterator_word_boundary(it)) {
1491 /* We've found a new boundary */
1494 /*fprintf(stderr, "[%zu, %zu) is a candidate word\n", b1, b2);*/
1495 /* Inspect the characters between the boundary and form an opinion as to
1496 * whether they are a word or not */
1498 for(i = b1; i < b2; ++i) {
1499 switch(utf32__iterator_word_break(it, it->s[i])) {
1500 case unicode_Word_Break_ALetter:
1501 case unicode_Word_Break_Numeric:
1502 case unicode_Word_Break_Katakana:
1509 /* If it's a word add it to the list of results */
1511 const size_t len = b2 - b1;
1512 w = xcalloc_noptr(len + 1, sizeof(uint32_t));
1513 memcpy(w, it->s + b1, len * sizeof (uint32_t));
1515 vector32_append(v32, w);
1518 } while(!utf32_iterator_advance(it, 1));
1519 vector32_terminate(v32);
1526 /** @defgroup utf8 Functions that operate on UTF-8 strings */
1529 /** @brief Wrapper to transform a UTF-8 string using the UTF-32 function */
1530 #define utf8__transform(FN) do { \
1531 uint32_t *to32 = 0, *decomp32 = 0; \
1532 size_t nto32, ndecomp32; \
1533 char *decomp8 = 0; \
1535 if(!(to32 = utf8_to_utf32(s, ns, &nto32))) goto error; \
1536 if(!(decomp32 = FN(to32, nto32, &ndecomp32))) goto error; \
1537 decomp8 = utf32_to_utf8(decomp32, ndecomp32, ndp); \
1544 /** @brief Canonically decompose @p [s,s+ns)
1545 * @param s Pointer to string
1546 * @param ns Length of string
1547 * @param ndp Where to store length of result
1548 * @return Pointer to result string, or NULL on error
1550 * Computes NFD (Normalization Form D) of the string at @p s. This implies
1551 * performing all canonical decompositions and then normalizing the order of
1552 * combining characters.
1554 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1558 * - utf32_decompose_canon().
1559 * - utf8_decompose_compat()
1560 * - utf8_compose_canon()
1562 char *utf8_decompose_canon(const char *s, size_t ns, size_t *ndp) {
1563 utf8__transform(utf32_decompose_canon);
1566 /** @brief Compatibility decompose @p [s,s+ns)
1567 * @param s Pointer to string
1568 * @param ns Length of string
1569 * @param ndp Where to store length of result
1570 * @return Pointer to result string, or NULL on error
1572 * Computes NFKD (Normalization Form KD) of the string at @p s. This implies
1573 * performing all canonical and compatibility decompositions and then
1574 * normalizing the order of combining characters.
1576 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1580 * - utf32_decompose_compat().
1581 * - utf8_decompose_canon()
1582 * - utf8_compose_compat()
1584 char *utf8_decompose_compat(const char *s, size_t ns, size_t *ndp) {
1585 utf8__transform(utf32_decompose_compat);
1588 /** @brief Canonically compose @p [s,s+ns)
1589 * @param s Pointer to string
1590 * @param ns Length of string
1591 * @param ndp Where to store length of result
1592 * @return Pointer to result string, or NULL on error
1594 * Computes NFC (Normalization Form C) of the string at @p s. This implies
1595 * performing all canonical decompositions, normalizing the order of combining
1596 * characters and then composing all unblocked primary compositables.
1598 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1602 * - utf32_compose_canon()
1603 * - utf8_compose_compat()
1604 * - utf8_decompose_canon()
1606 char *utf8_compose_canon(const char *s, size_t ns, size_t *ndp) {
1607 utf8__transform(utf32_compose_canon);
1610 /** @brief Compatibility compose @p [s,s+ns)
1611 * @param s Pointer to string
1612 * @param ns Length of string
1613 * @param ndp Where to store length of result
1614 * @return Pointer to result string, or NULL on error
1616 * Computes NFKC (Normalization Form KC) of the string at @p s. This implies
1617 * performing all canonical and compatibility decompositions, normalizing the
1618 * order of combining characters and then composing all unblocked primary
1621 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1625 * - utf32_compose_compat()
1626 * - utf8_compose_canon()
1627 * - utf8_decompose_compat()
1629 char *utf8_compose_compat(const char *s, size_t ns, size_t *ndp) {
1630 utf8__transform(utf32_compose_compat);
1633 /** @brief Case-fold @p [s,s+ns)
1634 * @param s Pointer to string
1635 * @param ns Length of string
1636 * @param ndp Where to store length of result
1637 * @return Pointer to result string, or NULL on error
1639 * Case-fold the string at @p s according to full default case-folding rules
1640 * (s3.13). The result will be in NFD.
1642 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1645 char *utf8_casefold_canon(const char *s, size_t ns, size_t *ndp) {
1646 utf8__transform(utf32_casefold_canon);
1649 /** @brief Compatibility case-fold @p [s,s+ns)
1650 * @param s Pointer to string
1651 * @param ns Length of string
1652 * @param ndp Where to store length of result
1653 * @return Pointer to result string, or NULL on error
1655 * Case-fold the string at @p s according to full default case-folding rules
1656 * (s3.13). The result will be in NFKD.
1658 * Returns NULL if the string is not valid; see utf8_to_utf32() for reasons why
1661 char *utf8_casefold_compat(const char *s, size_t ns, size_t *ndp) {
1662 utf8__transform(utf32_casefold_compat);
1665 /** @brief Split [s,ns) into multiple words
1666 * @param s Pointer to start of string
1667 * @param ns Length of string
1668 * @param nwp Where to store word count, or NULL
1669 * @param wbreak Word_Break property tailor, or NULL
1670 * @return Pointer to array of pointers to words
1672 * The returned array is terminated by a NULL pointer and individual
1673 * strings are 0-terminated.
1675 char **utf8_word_split(const char *s, size_t ns, size_t *nwp,
1676 unicode_property_tailor *wbreak) {
1677 uint32_t *to32 = 0, **v32 = 0;
1678 size_t nto32, nv, n;
1679 char **v8 = 0, **ret = 0;
1681 if(!(to32 = utf8_to_utf32(s, ns, &nto32))) goto error;
1682 if(!(v32 = utf32_word_split(to32, nto32, &nv, wbreak))) goto error;
1683 v8 = xcalloc(sizeof (char *), nv + 1);
1684 for(n = 0; n < nv; ++n)
1685 if(!(v8[n] = utf32_to_utf8(v32[n], utf32_len(v32[n]), 0)))
1689 v8 = 0; /* don't free */
1692 for(n = 0; n < nv; ++n)
1697 for(n = 0; n < nv; ++n)
1708 /** @brief Return the length of a 0-terminated UTF-16 string
1709 * @param s Pointer to 0-terminated string
1710 * @return Length of string in code points (excluding terminator)
1712 * Unlike the conversion functions no validity checking is done on the string.
1714 size_t utf16_len(const uint16_t *s) {
1715 const uint16_t *t = s;
1719 return (size_t)(t - s);
1727 indent-tabs-mode:nil