1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
<?php
/**
* Cross-Language Language name search
*
* Copyright (C) 2012 Alolita Sharma, Amir Aharoni, Arun Ganesh, Brandon Harris,
* Niklas Laxström, Pau Giner, Santhosh Thottingal, Siebrand Mazeland and other
* contributors. See CREDITS for a list.
*
* UniversalLanguageSelector is dual licensed GPLv2 or later and MIT. You don't
* have to do anything special to choose one license or the other and you don't
* have to notify anyone which license you are using. You are free to use
* UniversalLanguageSelector in commercial projects as long as the copyright
* header is left intact. See files GPL-LICENSE and MIT-LICENSE for details.
*
* @file
* @ingroup Extensions
* @license GPL-2.0-or-later
* @license MIT
*/
class LanguageNameSearch {
/**
* Find languages with fuzzy matching.
* The order of results is following:
* 1: exact language code match
* 2: exact language name match in any language
* 3: prefix language name match in any language
* 4: infix language name match in any language
*
* The returned language name for autocompletion is the first one that
* matches in this list:
* 1: exact match in [user, autonym, any other language]
* 2: prefix match in [user, autonym, any other language]
* 3: inline match in [user, autonym, any other language]
*
* @param string $searchKey
* @param int $typos
* @param string|null $userLanguage Language tag.
* @return array
*/
public static function search( $searchKey, $typos = 0, $userLanguage = null ) {
$results = [];
$searchKey = mb_strtolower( $searchKey );
if ( mb_strlen( $searchKey ) > 100 ) {
// Searching with long search keys for language names is not useful. So, return early.
return [];
}
// Always prefer exact language code match
if ( Language::isKnownLanguageTag( $searchKey ) ) {
$name = mb_strtolower( Language::fetchLanguageName( $searchKey, $userLanguage ) );
// Check if language code is a prefix of the name
if ( strpos( $name, $searchKey ) === 0 ) {
$results[$searchKey] = $name;
} else {
$results[$searchKey] = "$searchKey – $name";
}
}
$index = self::getIndex( $searchKey );
$bucketsForIndex = [];
if ( isset( LanguageNameSearchData::$buckets[$index] ) ) {
$bucketsForIndex = LanguageNameSearchData::$buckets[$index];
}
// types are 'prefix', 'infix' (in this order!)
foreach ( $bucketsForIndex as $bucketType => $bucket ) {
foreach ( $bucket as $name => $code ) {
// We can skip checking languages we already have in the list
if ( isset( $results[ $code ] ) ) {
continue;
}
// Apply fuzzy search
if ( !self::matchNames( $name, $searchKey, $typos ) ) {
continue;
}
// Once we find a match, figure out the best name to display to the user
// If $userLanguage is not provided (null), it is the same as autonym
$candidates = [
mb_strtolower( Language::fetchLanguageName( $code, $userLanguage ) ),
mb_strtolower( Language::fetchLanguageName( $code, null ) ),
$name
];
foreach ( $candidates as $candidate ) {
if ( $searchKey === $candidate ) {
$results[$code] = $candidate;
continue 2;
}
}
foreach ( $candidates as $candidate ) {
if ( self::matchNames( $candidate, $searchKey, $typos ) ) {
$results[$code] = $candidate;
continue 2;
}
}
}
}
return $results;
}
public static function matchNames( $name, $searchKey, $typos ) {
return strrpos( $name, $searchKey, -strlen( $name ) ) !== false
|| ( $typos > 0 && self::levenshteinDistance( $name, $searchKey ) <= $typos );
}
public static function getIndex( $name ) {
$codepoint = self::getCodepoint( $name );
if ( $codepoint < 4000 ) {
// For latin etc. we need smaller buckets for speed
return $codepoint;
} else {
// Try to group names of same script together
return $codepoint - ( $codepoint % 1000 );
}
}
/**
* Get the code point of first letter of string
*
* @param string $str
* @return int Code point of first letter of string
*/
public static function getCodepoint( $str ) {
$values = [];
$lookingFor = 1;
$strLen = strlen( $str );
$number = 0;
for ( $i = 0; $i < $strLen; $i++ ) {
$thisValue = ord( $str[$i] );
if ( $thisValue < 128 ) {
$number = $thisValue;
break;
} else {
// Codepoints larger than 127 are represented by multi-byte sequences
if ( $values === [] ) {
// 224 is the lowest non-overlong-encoded codepoint.
$lookingFor = ( $thisValue < 224 ) ? 2 : 3;
}
$values[] = $thisValue;
if ( count( $values ) === $lookingFor ) {
// Refer http://en.wikipedia.org/wiki/UTF-8#Description
if ( $lookingFor === 3 ) {
$number = ( $values[0] % 16 ) * 4096;
$number += ( $values[1] % 64 ) * 64;
$number += $values[2] % 64;
} else {
$number = ( $values[0] % 32 ) * 64;
$number += $values[1] % 64;
}
break;
}
}
}
return $number;
}
/**
* Calculate the Levenshtein distance between two strings
* @param string $str1
* @param string $str2
* @return int
*/
public static function levenshteinDistance( $str1, $str2 ) {
if ( $str1 === $str2 ) {
return 0;
}
$length1 = mb_strlen( $str1, 'UTF-8' );
$length2 = mb_strlen( $str2, 'UTF-8' );
if ( $length1 === 0 ) {
return $length2;
}
if ( $length1 < $length2 ) {
return self::levenshteinDistance( $str2, $str1 );
}
$prevRow = range( 0, $length2 );
for ( $i = 0; $i < $length1; $i++ ) {
$currentRow = [];
$currentRow[0] = $i + 1;
$c1 = mb_substr( $str1, $i, 1, 'UTF-8' );
for ( $j = 0; $j < $length2; $j++ ) {
$c2 = mb_substr( $str2, $j, 1, 'UTF-8' );
$insertions = $prevRow[$j + 1] + 1;
$deletions = $currentRow[$j] + 1;
$substitutions = $prevRow[$j] + ( ( $c1 !== $c2 ) ? 1 : 0 );
$currentRow[] = min( $insertions, $deletions, $substitutions );
}
$prevRow = $currentRow;
}
return $prevRow[$length2];
}
}
|