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Add grapheme_levenshtein function.
Measure levenshtein for grapheme cluster unit
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‎ext/intl/grapheme/grapheme_string.c

Lines changed: 181 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -918,4 +918,185 @@ PHP_FUNCTION(grapheme_str_split)
918918
ubrk_close(bi);
919919
}
920920

921+
PHP_FUNCTION(grapheme_levenshtein)
922+
{
923+
zend_string *string1, *string2;
924+
zend_long cost_ins = 1;
925+
zend_long cost_rep = 1;
926+
zend_long cost_del = 1;
927+
928+
ZEND_PARSE_PARAMETERS_START(2, 5)
929+
Z_PARAM_STR(string1)
930+
Z_PARAM_STR(string2)
931+
Z_PARAM_OPTIONAL
932+
Z_PARAM_LONG(cost_ins)
933+
Z_PARAM_LONG(cost_rep)
934+
Z_PARAM_LONG(cost_del)
935+
ZEND_PARSE_PARAMETERS_END();
936+
937+
if (cost_ins <= 0 || cost_ins > UINT_MAX / 4) {
938+
zend_argument_value_error(3, "must be greater than 0 and less than or equal to %d", UINT_MAX / 4);
939+
RETURN_THROWS();
940+
}
941+
942+
if (cost_rep <= 0 || cost_rep > UINT_MAX / 4) {
943+
zend_argument_value_error(4, "must be greater than 0 and less than or equal to %d", UINT_MAX / 4);
944+
RETURN_THROWS();
945+
}
946+
947+
if (cost_del <= 0 || cost_del > UINT_MAX / 4) {
948+
zend_argument_value_error(5, "must be greater than 0 and less than or equal to %d", UINT_MAX / 4);
949+
RETURN_THROWS();
950+
}
951+
952+
zend_long *p1, *p2, *tmp;
953+
zend_long c0, c1, c2;
954+
zend_long retval;
955+
size_t i2;
956+
char *pstr1, *pstr2;
957+
958+
UChar *ustring1 = NULL;
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UChar *ustring2 = NULL;
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961+
int32_t ustring1_len = 0;
962+
int32_t ustring2_len = 0;
963+
964+
UErrorCode ustatus1 = U_ZERO_ERROR;
965+
UErrorCode ustatus2 = U_ZERO_ERROR;
966+
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/* When all costs are equal, levenshtein fulfills the requirements of a metric, which means
968+
* that the distance is symmetric. If string1 is shorter than string 2 we can save memory (and CPU time)
969+
* by having shorter rows (p1 & p2). */
970+
if (ZSTR_LEN(string1) < ZSTR_LEN(string2) && cost_ins == cost_rep && cost_rep == cost_del) {
971+
zend_string *tmp = string1;
972+
string1 = string2;
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string2 = tmp;
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}
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pstr1 = ZSTR_VAL(string1);
977+
pstr2 = ZSTR_VAL(string2);
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intl_convert_utf8_to_utf16(&ustring1, &ustring1_len, pstr1, ZSTR_LEN(string1), &ustatus1);
980+
981+
if ( U_FAILURE( ustatus1 ) ) {
982+
/* Set global error code. */
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intl_error_set_code( NULL, ustatus1 );
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/* Set error messages. */
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intl_error_set_custom_msg( NULL, "Error converting input string to UTF-16", 0 );
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if (ustring1) {
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efree( ustring1 );
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}
990+
RETURN_FALSE;
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}
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intl_convert_utf8_to_utf16(&ustring2, &ustring2_len, pstr2, ZSTR_LEN(string2), &ustatus2);
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if ( U_FAILURE( ustatus2 ) ) {
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/* Set global error code. */
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intl_error_set_code( NULL, ustatus2 );
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/* Set error messages. */
1000+
intl_error_set_custom_msg( NULL, "Error converting input string to UTF-16", 0 );
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if (ustring2) {
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efree( ustring2 );
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}
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if (ustring1) {
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efree( ustring1 );
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}
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RETURN_FALSE;
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}
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UText *ut1 = NULL;
1011+
UText *ut2 = NULL;
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UBreakIterator *bi1, *bi2;
1013+
1014+
int32_t strlen_1, strlen_2;
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strlen_1 = grapheme_split_string(ustring1, ustring1_len, NULL, 0 );
1016+
strlen_2 = grapheme_split_string(ustring2, ustring2_len, NULL, 0 );
1017+
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if (strlen_1 == 0) {
1019+
efree(ustring1);
1020+
efree(ustring2);
1021+
RETURN_LONG(strlen_2 * cost_ins);
1022+
}
1023+
if (strlen_2 == 0) {
1024+
efree(ustring1);
1025+
efree(ustring2);
1026+
RETURN_LONG(strlen_1 * cost_del);
1027+
}
1028+
1029+
unsigned char u_break_iterator_buffer1[U_BRK_SAFECLONE_BUFFERSIZE];
1030+
unsigned char u_break_iterator_buffer2[U_BRK_SAFECLONE_BUFFERSIZE];
1031+
bi1 = grapheme_get_break_iterator((void*)u_break_iterator_buffer1, &ustatus1 );
1032+
bi2 = grapheme_get_break_iterator((void*)u_break_iterator_buffer2, &ustatus2 );
1033+
1034+
ut1 = utext_openUTF8(ut1, pstr1, ZSTR_LEN(string1), &ustatus1);
1035+
ubrk_setUText(bi1, ut1, &ustatus1);
1036+
ut2 = utext_openUTF8(ut2, pstr2, ZSTR_LEN(string2), &ustatus2);
1037+
ubrk_setUText(bi2, ut2, &ustatus2);
1038+
1039+
p1 = safe_emalloc(strlen_2 + 1, sizeof(zend_long), 0);
1040+
p2 = safe_emalloc(strlen_2 + 1, sizeof(zend_long), 0);
1041+
1042+
for (i2 = 0; i2 <= strlen_2; i2++) {
1043+
p1[i2] = i2 * cost_ins;
1044+
}
1045+
1046+
int32_t current1 = 0;
1047+
int32_t current2 = 0;
1048+
int32_t pos1 = 0;
1049+
int32_t pos2 = 0;
1050+
int32_t usrch_pos = 0;
1051+
for ( ; pos1 != UBRK_DONE; ) {
1052+
current1 = ubrk_current(bi1);
1053+
pos1 = ubrk_next(bi1);
1054+
if (pos1 == UBRK_DONE) {
1055+
break;
1056+
}
1057+
p2[0] = p1[0] + cost_del;
1058+
for (i2 = 0, pos2 = 0; pos2 != UBRK_DONE; i2++) {
1059+
current2 = ubrk_current(bi2);
1060+
pos2 = ubrk_next(bi2);
1061+
if (pos2 == UBRK_DONE) {
1062+
break;
1063+
}
1064+
usrch_pos = grapheme_strpos_utf16(pstr1 + current1, pos1 - current1, pstr2 + current2, pos2 - current2, 0, NULL, 0, 0);
1065+
if (usrch_pos == 0) {
1066+
c0 = p1[i2];
1067+
} else {
1068+
c0 = p1[i2] + cost_rep;
1069+
}
1070+
c1 = p1[i2 + 1] + cost_del;
1071+
if (c1 < c0) {
1072+
c0 = c1;
1073+
}
1074+
c2 = p2[i2] + cost_ins;
1075+
if (c2 < c0) {
1076+
c0 = c2;
1077+
}
1078+
p2[i2 + 1] = c0;
1079+
}
1080+
ubrk_first(bi2);
1081+
tmp = p1;
1082+
p1 = p2;
1083+
p2 = tmp;
1084+
}
1085+
1086+
utext_close(ut1);
1087+
utext_close(ut2);
1088+
1089+
ubrk_close(bi1);
1090+
ubrk_close(bi2);
1091+
1092+
efree(ustring1);
1093+
efree(ustring2);
1094+
1095+
retval = p1[strlen_2];
1096+
1097+
efree(p1);
1098+
efree(p2);
1099+
RETURN_LONG(retval);
1100+
}
1101+
9211102
/* }}} */

‎ext/intl/php_intl.stub.php

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -447,6 +447,8 @@ function grapheme_stristr(string $haystack, string $needle, bool $beforeNeedle =
447447

448448
function grapheme_str_split(string $string, int $length = 1): array|false {}
449449

450+
function grapheme_levenshtein(string $string1, string $string2, int $insertion_cost = 1, int $replacement_cost = 1, int $deletion_cost = 1): int|false {}
451+
450452
/** @param int $next */
451453
function grapheme_extract(string $haystack, int $size, int $type = GRAPHEME_EXTR_COUNT, int $offset = 0, &$next = null): string|false {}
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‎ext/intl/php_intl_arginfo.h

Lines changed: 11 additions & 1 deletion
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‎ext/intl/tests/grapheme_levenshtein.phpt

Lines changed: 104 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,104 @@
1+
--TEST--
2+
grapheme_levenshtein() function test
3+
--EXTENSIONS--
4+
intl
5+
--FILE--
6+
<?php
7+
echo '--- Equal ---' . \PHP_EOL;
8+
var_dump(grapheme_levenshtein('12345', '12345'));
9+
10+
echo '--- First string empty ---' . \PHP_EOL;
11+
var_dump(grapheme_levenshtein('', 'xyz'));
12+
echo '--- Second string empty ---' . \PHP_EOL;
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var_dump(grapheme_levenshtein('xyz', ''));
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echo '--- Both empty ---' . \PHP_EOL;
15+
var_dump(grapheme_levenshtein('', ''));
16+
var_dump(grapheme_levenshtein('', '', 10, 10, 10));
17+
18+
echo '--- 1 character ---' . \PHP_EOL;
19+
var_dump(grapheme_levenshtein('1', '2'));
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echo '--- 2 character swapped ---' . \PHP_EOL;
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var_dump(grapheme_levenshtein('12', '21'));
22+
23+
echo '--- Inexpensive deletion ---' . \PHP_EOL;
24+
var_dump(grapheme_levenshtein('2121', '11', 2));
25+
echo '--- Expensive deletion ---' . \PHP_EOL;
26+
var_dump(grapheme_levenshtein('2121', '11', 2, 1, 5));
27+
28+
//
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echo '--- Inexpensive insertion ---' . \PHP_EOL;
30+
var_dump(grapheme_levenshtein('11', '2121'));
31+
echo '--- Expensive insertion ---' . \PHP_EOL;
32+
var_dump(grapheme_levenshtein('11', '2121', 5));
33+
34+
echo '--- Expensive replacement ---' . \PHP_EOL;
35+
var_dump(grapheme_levenshtein('111', '121', 2, 3, 2));
36+
echo '--- Very expensive replacement ---' . \PHP_EOL;
37+
var_dump(grapheme_levenshtein('111', '121', 2, 9, 2));
38+
39+
echo '--- 128 codepoints ---' . \PHP_EOL;
40+
var_dump(grapheme_levenshtein(str_repeat("a", 128), str_repeat("a", 125) . "abc"));
41+
echo '--- 128 codepoints over ---' . \PHP_EOL;
42+
var_dump(grapheme_levenshtein(str_repeat("a", 128) . "abc", str_repeat("a", 128) . "aaa"));
43+
var_dump(grapheme_levenshtein(str_repeat("a", 256) . "abc", "aaa"));
44+
echo '--- 128 codepoints over only $string1 ---' . \PHP_EOL;
45+
var_dump(grapheme_levenshtein(str_repeat("a", 128) . "abc", "aaa"));
46+
echo '--- 128 codepoints over only $string2 ---' . \PHP_EOL;
47+
var_dump(grapheme_levenshtein("abc", str_repeat("a", 128) . "aaa"));
48+
echo '--- 128 codepoints over Hiragana ---' . \PHP_EOL;
49+
var_dump(grapheme_levenshtein(str_repeat("あ", 128) . "あああ", str_repeat("あ", 128) . "あいう"));
50+
51+
echo '--- Variable selector ---' . \PHP_EOL;
52+
$ka = "カ́";
53+
var_dump(grapheme_levenshtein("カ", $ka));
54+
// variable $nabe and $nabe_E0100 is seems nothing different.
55+
// However, $nabe_E0100 is variable selector in U+908A U+E0100.
56+
// So grapheme_levenshtein result is maybe 0.
57+
$nabe = '邊';
58+
$nabe_E0100 = "邊󠄀";
59+
var_dump(grapheme_levenshtein($nabe, $nabe_E0100));
60+
61+
// combining character
62+
var_dump(grapheme_levenshtein("\u{0065}\u{0301}", "\u{00e9}"));
63+
?>
64+
--EXPECT--
65+
--- Equal ---
66+
int(0)
67+
--- First string empty ---
68+
int(3)
69+
--- Second string empty ---
70+
int(3)
71+
--- Both empty ---
72+
int(0)
73+
int(0)
74+
--- 1 character ---
75+
int(1)
76+
--- 2 character swapped ---
77+
int(2)
78+
--- Inexpensive deletion ---
79+
int(2)
80+
--- Expensive deletion ---
81+
int(10)
82+
--- Inexpensive insertion ---
83+
int(2)
84+
--- Expensive insertion ---
85+
int(10)
86+
--- Expensive replacement ---
87+
int(3)
88+
--- Very expensive replacement ---
89+
int(4)
90+
--- 128 codepoints ---
91+
int(2)
92+
--- 128 codepoints over ---
93+
int(2)
94+
int(256)
95+
--- 128 codepoints over only $string1 ---
96+
int(128)
97+
--- 128 codepoints over only $string2 ---
98+
int(130)
99+
--- 128 codepoints over Hiragana ---
100+
int(2)
101+
--- Variable selector ---
102+
int(1)
103+
int(0)
104+
int(0)

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