xref: /dokuwiki/inc/fulltext.php (revision 9d706dd2a380574a0f89b771c7b3fd9a77de9dc7) 
1<?php
2/**
3 * DokuWiki fulltextsearch functions using the index
4 *
5 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6 * @author     Andreas Gohr <andi@splitbrain.org>
7 */
8
9if(!defined('DOKU_INC')) die('meh.');
10
11/**
12 * create snippets for the first few results only
13 */
14if(!defined('FT_SNIPPET_NUMBER')) define('FT_SNIPPET_NUMBER',15);
15
16/**
17 * The fulltext search
18 *
19 * Returns a list of matching documents for the given query
20 *
21 * refactored into ft_pageSearch(), _ft_pageSearch() and trigger_event()
22 *
23 */
24function ft_pageSearch($query,&$highlight){
25
26    $data['query'] = $query;
27    $data['highlight'] =& $highlight;
28
29    return trigger_event('SEARCH_QUERY_FULLPAGE', $data, '_ft_pageSearch');
30}
31
32/**
33 * Returns a list of matching documents for the given query
34 *
35 * @author Andreas Gohr <andi@splitbrain.org>
36 * @author Kazutaka Miyasaka <kazmiya@gmail.com>
37 */
38function _ft_pageSearch(&$data) {
39    // parse the given query
40    $q = ft_queryParser($data['query']);
41    $data['highlight'] = $q['highlight'];
42
43    if (empty($q['parsed_ary'])) return array();
44
45    // lookup all words found in the query
46    $lookup = idx_lookup($q['words']);
47
48    // get all pages in this dokuwiki site (!: includes nonexistent pages)
49    $pages_all = array();
50    foreach (idx_getIndex('page', '') as $id) {
51        $pages_all[trim($id)] = 0; // base: 0 hit
52    }
53
54    // process the query
55    $stack = array();
56    foreach ($q['parsed_ary'] as $token) {
57        switch (substr($token, 0, 3)) {
58            case 'W+:':
59            case 'W-:':
60            case 'W_:': // word
61                $word    = substr($token, 3);
62                $stack[] = (array) $lookup[$word];
63                break;
64            case 'P+:':
65            case 'P-:': // phrase
66                $phrase = substr($token, 3);
67                // since phrases are always parsed as ((W1)(W2)...(P)),
68                // the end($stack) always points the pages that contain
69                // all words in this phrase
70                $pages  = end($stack);
71                $pages_matched = array();
72                foreach(array_keys($pages) as $id){
73                    $text = utf8_strtolower(rawWiki($id));
74                    if (strpos($text, $phrase) !== false) {
75                        $pages_matched[$id] = 0; // phrase: always 0 hit
76                    }
77                }
78                $stack[] = $pages_matched;
79                break;
80            case 'N+:':
81            case 'N-:': // namespace
82                $ns = substr($token, 3);
83                $pages_matched = array();
84                foreach (array_keys($pages_all) as $id) {
85                    if (strpos($id, $ns) === 0) {
86                        $pages_matched[$id] = 0; // namespace: always 0 hit
87                    }
88                }
89                $stack[] = $pages_matched;
90                break;
91            case 'AND': // and operation
92                list($pages1, $pages2) = array_splice($stack, -2);
93                $stack[] = ft_resultCombine(array($pages1, $pages2));
94                break;
95            case 'OR':  // or operation
96                list($pages1, $pages2) = array_splice($stack, -2);
97                $stack[] = ft_resultUnite(array($pages1, $pages2));
98                break;
99            case 'NOT': // not operation (unary)
100                $pages   = array_pop($stack);
101                $stack[] = ft_resultComplement(array($pages_all, $pages));
102                break;
103        }
104    }
105    $docs = array_pop($stack);
106
107    if (empty($docs)) return array();
108
109    // check: settings, acls, existence
110    foreach (array_keys($docs) as $id) {
111        if (isHiddenPage($id) || auth_quickaclcheck($id) < AUTH_READ || !page_exists($id, '', false)) {
112            unset($docs[$id]);
113        }
114    }
115
116    // sort docs by count
117    arsort($docs);
118
119    return $docs;
120}
121
122/**
123 * Returns the backlinks for a given page
124 *
125 * Does a quick lookup with the fulltext index, then
126 * evaluates the instructions of the found pages
127 */
128function ft_backlinks($id){
129    global $conf;
130    $swfile   = DOKU_INC.'inc/lang/'.$conf['lang'].'/stopwords.txt';
131    $stopwords = @file_exists($swfile) ? file($swfile) : array();
132
133    $result = array();
134
135    // quick lookup of the pagename
136    $page    = noNS($id);
137    $matches = idx_lookup(idx_tokenizer($page,$stopwords));  // pagename may contain specials (_ or .)
138    $docs    = array_keys(ft_resultCombine(array_values($matches)));
139    $docs    = array_filter($docs,'isVisiblePage'); // discard hidden pages
140    if(!count($docs)) return $result;
141
142    // check metadata for matching links
143    foreach($docs as $match){
144        // metadata relation reference links are already resolved
145        $links = p_get_metadata($match,'relation references');
146        if (isset($links[$id])) $result[] = $match;
147    }
148
149    if(!count($result)) return $result;
150
151    // check ACL permissions
152    foreach(array_keys($result) as $idx){
153        if(auth_quickaclcheck($result[$idx]) < AUTH_READ){
154            unset($result[$idx]);
155        }
156    }
157
158    sort($result);
159    return $result;
160}
161
162/**
163 * Returns the pages that use a given media file
164 *
165 * Does a quick lookup with the fulltext index, then
166 * evaluates the instructions of the found pages
167 *
168 * Aborts after $max found results
169 */
170function ft_mediause($id,$max){
171    global $conf;
172    $swfile   = DOKU_INC.'inc/lang/'.$conf['lang'].'/stopwords.txt';
173    $stopwords = @file_exists($swfile) ? file($swfile) : array();
174
175    if(!$max) $max = 1; // need to find at least one
176
177    $result = array();
178
179    // quick lookup of the mediafile
180    $media   = noNS($id);
181    $matches = idx_lookup(idx_tokenizer($media,$stopwords));
182    $docs    = array_keys(ft_resultCombine(array_values($matches)));
183    if(!count($docs)) return $result;
184
185    // go through all found pages
186    $found = 0;
187    $pcre  = preg_quote($media,'/');
188    foreach($docs as $doc){
189        $ns = getNS($doc);
190        preg_match_all('/\{\{([^|}]*'.$pcre.'[^|}]*)(|[^}]+)?\}\}/i',rawWiki($doc),$matches);
191        foreach($matches[1] as $img){
192            $img = trim($img);
193            if(preg_match('/^https?:\/\//i',$img)) continue; // skip external images
194                list($img) = explode('?',$img);                  // remove any parameters
195            resolve_mediaid($ns,$img,$exists);               // resolve the possibly relative img
196
197            if($img == $id){                                 // we have a match
198                $result[] = $doc;
199                $found++;
200                break;
201            }
202        }
203        if($found >= $max) break;
204    }
205
206    sort($result);
207    return $result;
208}
209
210
211
212/**
213 * Quicksearch for pagenames
214 *
215 * By default it only matches the pagename and ignores the
216 * namespace. This can be changed with the second parameter
217 *
218 * refactored into ft_pageLookup(), _ft_pageLookup() and trigger_event()
219 *
220 * @author Andreas Gohr <andi@splitbrain.org>
221 */
222function ft_pageLookup($id,$pageonly=true){
223    $data = array('id' => $id, 'pageonly' => $pageonly);
224    return trigger_event('SEARCH_QUERY_PAGELOOKUP',$data,'_ft_pageLookup');
225}
226
227function _ft_pageLookup(&$data){
228    // split out original parameterrs
229    $id = $data['id'];
230    $pageonly = $data['pageonly'];
231
232    global $conf;
233    $id    = preg_quote($id,'/');
234    $pages = file($conf['indexdir'].'/page.idx');
235    if($id) $pages = array_values(preg_grep('/'.$id.'/',$pages));
236
237    $cnt = count($pages);
238    for($i=0; $i<$cnt; $i++){
239        if($pageonly){
240            if(!preg_match('/'.$id.'/',noNS($pages[$i]))){
241                unset($pages[$i]);
242                continue;
243            }
244        }
245        if(!page_exists($pages[$i])){
246            unset($pages[$i]);
247            continue;
248        }
249    }
250
251    $pages = array_filter($pages,'isVisiblePage'); // discard hidden pages
252    if(!count($pages)) return array();
253
254    // check ACL permissions
255    foreach(array_keys($pages) as $idx){
256        if(auth_quickaclcheck(trim($pages[$idx])) < AUTH_READ){
257            unset($pages[$idx]);
258        }
259    }
260
261    $pages = array_map('trim',$pages);
262    usort($pages,'ft_pagesorter');
263    return $pages;
264}
265
266/**
267 * Sort pages based on their namespace level first, then on their string
268 * values. This makes higher hierarchy pages rank higher than lower hierarchy
269 * pages.
270 */
271function ft_pagesorter($a, $b){
272    $ac = count(explode(':',$a));
273    $bc = count(explode(':',$b));
274    if($ac < $bc){
275        return -1;
276    }elseif($ac > $bc){
277        return 1;
278    }
279    return strcmp ($a,$b);
280}
281
282/**
283 * Creates a snippet extract
284 *
285 * @author Andreas Gohr <andi@splitbrain.org>
286 * @triggers FULLTEXT_SNIPPET_CREATE
287 */
288function ft_snippet($id,$highlight){
289    $text = rawWiki($id);
290    $evdata = array(
291            'id'        => $id,
292            'text'      => &$text,
293            'highlight' => &$highlight,
294            'snippet'   => '',
295            );
296
297    $evt = new Doku_Event('FULLTEXT_SNIPPET_CREATE',$evdata);
298    if ($evt->advise_before()) {
299        $match = array();
300        $snippets = array();
301        $utf8_offset = $offset = $end = 0;
302        $len = utf8_strlen($text);
303
304        // build a regexp from the phrases to highlight
305        $re1 = '('.join('|',array_map('preg_quote_cb',array_filter((array) $highlight))).')';
306        $re2 = "$re1.{0,75}(?!\\1)$re1";
307        $re3 = "$re1.{0,45}(?!\\1)$re1.{0,45}(?!\\1)(?!\\2)$re1";
308
309        for ($cnt=4; $cnt--;) {
310            if (0) {
311            } else if (preg_match('/'.$re3.'/iu',$text,$match,PREG_OFFSET_CAPTURE,$offset)) {
312            } else if (preg_match('/'.$re2.'/iu',$text,$match,PREG_OFFSET_CAPTURE,$offset)) {
313            } else if (preg_match('/'.$re1.'/iu',$text,$match,PREG_OFFSET_CAPTURE,$offset)) {
314            } else {
315                break;
316            }
317
318            list($str,$idx) = $match[0];
319
320            // convert $idx (a byte offset) into a utf8 character offset
321            $utf8_idx = utf8_strlen(substr($text,0,$idx));
322            $utf8_len = utf8_strlen($str);
323
324            // establish context, 100 bytes surrounding the match string
325            // first look to see if we can go 100 either side,
326            // then drop to 50 adding any excess if the other side can't go to 50,
327            $pre = min($utf8_idx-$utf8_offset,100);
328            $post = min($len-$utf8_idx-$utf8_len,100);
329
330            if ($pre>50 && $post>50) {
331                $pre = $post = 50;
332            } else if ($pre>50) {
333                $pre = min($pre,100-$post);
334            } else if ($post>50) {
335                $post = min($post, 100-$pre);
336            } else {
337                // both are less than 50, means the context is the whole string
338                // make it so and break out of this loop - there is no need for the
339                // complex snippet calculations
340                $snippets = array($text);
341                break;
342            }
343
344            // establish context start and end points, try to append to previous
345            // context if possible
346            $start = $utf8_idx - $pre;
347            $append = ($start < $end) ? $end : false;  // still the end of the previous context snippet
348            $end = $utf8_idx + $utf8_len + $post;      // now set it to the end of this context
349
350            if ($append) {
351                $snippets[count($snippets)-1] .= utf8_substr($text,$append,$end-$append);
352            } else {
353                $snippets[] = utf8_substr($text,$start,$end-$start);
354            }
355
356            // set $offset for next match attempt
357            //   substract strlen to avoid splitting a potential search success,
358            //   this is an approximation as the search pattern may match strings
359            //   of varying length and it will fail if the context snippet
360            //   boundary breaks a matching string longer than the current match
361            $utf8_offset = $utf8_idx + $post;
362            $offset = $idx + strlen(utf8_substr($text,$utf8_idx,$post));
363            $offset = utf8_correctIdx($text,$offset);
364        }
365
366        $m = "\1";
367        $snippets = preg_replace('/'.$re1.'/iu',$m.'$1'.$m,$snippets);
368        $snippet = preg_replace('/'.$m.'([^'.$m.']*?)'.$m.'/iu','<strong class="search_hit">$1</strong>',hsc(join('... ',$snippets)));
369
370        $evdata['snippet'] = $snippet;
371    }
372    $evt->advise_after();
373    unset($evt);
374
375    return $evdata['snippet'];
376}
377
378/**
379 * Combine found documents and sum up their scores
380 *
381 * This function is used to combine searched words with a logical
382 * AND. Only documents available in all arrays are returned.
383 *
384 * based upon PEAR's PHP_Compat function for array_intersect_key()
385 *
386 * @param array $args An array of page arrays
387 */
388function ft_resultCombine($args){
389    $array_count = count($args);
390    if($array_count == 1){
391        return $args[0];
392    }
393
394    $result = array();
395    if ($array_count > 1) {
396        foreach ($args[0] as $key => $value) {
397            $result[$key] = $value;
398            for ($i = 1; $i !== $array_count; $i++) {
399                if (!isset($args[$i][$key])) {
400                    unset($result[$key]);
401                    break;
402                }
403                $result[$key] += $args[$i][$key];
404            }
405        }
406    }
407    return $result;
408}
409
410/**
411 * Unites found documents and sum up their scores
412 *
413 * based upon ft_resultCombine() function
414 *
415 * @param array $args An array of page arrays
416 * @author Kazutaka Miyasaka <kazmiya@gmail.com>
417 */
418function ft_resultUnite($args) {
419    $array_count = count($args);
420    if ($array_count === 1) {
421        return $args[0];
422    }
423
424    $result = $args[0];
425    for ($i = 1; $i !== $array_count; $i++) {
426        foreach (array_keys($args[$i]) as $id) {
427            $result[$id] += $args[$i][$id];
428        }
429    }
430    return $result;
431}
432
433/**
434 * Computes the difference of documents using page id for comparison
435 *
436 * nearly identical to PHP5's array_diff_key()
437 *
438 * @param array $args An array of page arrays
439 * @author Kazutaka Miyasaka <kazmiya@gmail.com>
440 */
441function ft_resultComplement($args) {
442    $array_count = count($args);
443    if ($array_count === 1) {
444        return $args[0];
445    }
446
447    $result = $args[0];
448    foreach (array_keys($result) as $id) {
449        for ($i = 1; $i !== $array_count; $i++) {
450            if (isset($args[$i][$id])) unset($result[$id]);
451        }
452    }
453    return $result;
454}
455
456/**
457 * Parses a search query and builds an array of search formulas
458 *
459 * @author Andreas Gohr <andi@splitbrain.org>
460 * @author Kazutaka Miyasaka <kazmiya@gmail.com>
461 */
462function ft_queryParser($query){
463    global $conf;
464    $swfile    = DOKU_INC.'inc/lang/'.$conf['lang'].'/stopwords.txt';
465    $stopwords = @file_exists($swfile) ? file($swfile) : array();
466
467    /**
468     * parse a search query and transform it into intermediate representation
469     *
470     * in a search query, you can use the following expressions:
471     *
472     *   words:
473     *     include
474     *     -exclude
475     *   phrases:
476     *     "phrase to be included"
477     *     -"phrase you want to exclude"
478     *   namespaces:
479     *     @include:namespace (or ns:include:namespace)
480     *     ^exclude:namespace (or -ns:exclude:namespace)
481     *   groups:
482     *     ()
483     *     -()
484     *   operators:
485     *     and ('and' is the default operator: you can always omit this)
486     *     or  (or pipe symbol '|', lower precedence than 'and')
487     *
488     * e.g. a query [ aa "bb cc" @dd:ee ] means "search pages which contain
489     *      a word 'aa', a phrase 'bb cc' and are within a namespace 'dd:ee'".
490     *      this query is equivalent to [ -(-aa or -"bb cc" or -ns:dd:ee) ]
491     *      as long as you don't mind hit counts.
492     *
493     * intermediate representation consists of the following parts:
494     *
495     *   ( )           - group
496     *   AND           - logical and
497     *   OR            - logical or
498     *   NOT           - logical not
499     *   W+:, W-:, W_: - word      (underscore: no need to highlight)
500     *   P+:, P-:      - phrase    (minus sign: logically in NOT group)
501     *   N+:, N-:      - namespace
502     */
503    $parsed_query = '';
504    $parens_level = 0;
505    $terms = preg_split('/(-?".*?")/u', utf8_strtolower($query), -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
506
507    foreach ($terms as $term) {
508        $parsed = '';
509        if (preg_match('/^(-?)"(.+)"$/u', $term, $matches)) {
510            // phrase-include and phrase-exclude
511            $not = $matches[1] ? 'NOT' : '';
512            $parsed = $not.ft_termParser($matches[2], $stopwords, false, true);
513        } else {
514            // fix incomplete phrase
515            $term = str_replace('"', ' ', $term);
516
517            // fix parentheses
518            $term = str_replace(')'  , ' ) ', $term);
519            $term = str_replace('('  , ' ( ', $term);
520            $term = str_replace('- (', ' -(', $term);
521
522            // treat pipe symbols as 'OR' operators
523            $term = str_replace('|', ' or ', $term);
524
525            // treat ideographic spaces (U+3000) as search term separators
526            // FIXME: some more separators?
527            $term = preg_replace('/[ \x{3000}]+/u', ' ',  $term);
528            $term = trim($term);
529            if ($term === '') continue;
530
531            $tokens = explode(' ', $term);
532            foreach ($tokens as $token) {
533                if ($token === '(') {
534                    // parenthesis-include-open
535                    $parsed .= '(';
536                    ++$parens_level;
537                } elseif ($token === '-(') {
538                    // parenthesis-exclude-open
539                    $parsed .= 'NOT(';
540                    ++$parens_level;
541                } elseif ($token === ')') {
542                    // parenthesis-any-close
543                    if ($parens_level === 0) continue;
544                    $parsed .= ')';
545                    $parens_level--;
546                } elseif ($token === 'and') {
547                    // logical-and (do nothing)
548                } elseif ($token === 'or') {
549                    // logical-or
550                    $parsed .= 'OR';
551                } elseif (preg_match('/^(?:\^|-ns:)(.+)$/u', $token, $matches)) {
552                    // namespace-exclude
553                    $parsed .= 'NOT(N+:'.$matches[1].')';
554                } elseif (preg_match('/^(?:@|ns:)(.+)$/u', $token, $matches)) {
555                    // namespace-include
556                    $parsed .= '(N+:'.$matches[1].')';
557                } elseif (preg_match('/^-(.+)$/', $token, $matches)) {
558                    // word-exclude
559                    $parsed .= 'NOT('.ft_termParser($matches[1], $stopwords).')';
560                } else {
561                    // word-include
562                    $parsed .= ft_termParser($token, $stopwords);
563                }
564            }
565        }
566        $parsed_query .= $parsed;
567    }
568
569    // cleanup (very sensitive)
570    $parsed_query .= str_repeat(')', $parens_level);
571    do {
572        $parsed_query_old = $parsed_query;
573        $parsed_query = preg_replace('/(NOT)?\(\)/u', '', $parsed_query);
574    } while ($parsed_query !== $parsed_query_old);
575    $parsed_query = preg_replace('/(NOT|OR)+\)/u', ')'      , $parsed_query);
576    $parsed_query = preg_replace('/(OR)+/u'      , 'OR'     , $parsed_query);
577    $parsed_query = preg_replace('/\(OR/u'       , '('      , $parsed_query);
578    $parsed_query = preg_replace('/^OR|OR$/u'    , ''       , $parsed_query);
579    $parsed_query = preg_replace('/\)(NOT)?\(/u' , ')AND$1(', $parsed_query);
580
581    // adjustment: make highlightings right
582    $parens_level     = 0;
583    $notgrp_levels    = array();
584    $parsed_query_new = '';
585    $tokens = preg_split('/(NOT\(|[()])/u', $parsed_query, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
586    foreach ($tokens as $token) {
587        if ($token === 'NOT(') {
588            $notgrp_levels[] = ++$parens_level;
589        } elseif ($token === '(') {
590            ++$parens_level;
591        } elseif ($token === ')') {
592            if ($parens_level-- === end($notgrp_levels)) array_pop($notgrp_levels);
593        } elseif (count($notgrp_levels) % 2 === 1) {
594            // turn highlight-flag off if terms are logically in "NOT" group
595            $token = preg_replace('/([WPN])\+\:/u', '$1-:', $token);
596        }
597        $parsed_query_new .= $token;
598    }
599    $parsed_query = $parsed_query_new;
600
601    /**
602     * convert infix notation string into postfix (Reverse Polish notation) array
603     * by Shunting-yard algorithm
604     *
605     * see: http://en.wikipedia.org/wiki/Reverse_Polish_notation
606     * see: http://en.wikipedia.org/wiki/Shunting-yard_algorithm
607     */
608    $parsed_ary     = array();
609    $ope_stack      = array();
610    $ope_precedence = array(')' => 1, 'OR' => 2, 'AND' => 3, 'NOT' => 4, '(' => 5);
611    $ope_regex      = '/([()]|OR|AND|NOT)/u';
612
613    $tokens = preg_split($ope_regex, $parsed_query, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
614    foreach ($tokens as $token) {
615        if (preg_match($ope_regex, $token)) {
616            // operator
617            $last_ope = end($ope_stack);
618            while ($ope_precedence[$token] <= $ope_precedence[$last_ope] && $last_ope != '(') {
619                $parsed_ary[] = array_pop($ope_stack);
620                $last_ope = end($ope_stack);
621            }
622            if ($token == ')') {
623                array_pop($ope_stack); // this array_pop always deletes '('
624            } else {
625                $ope_stack[] = $token;
626            }
627        } else {
628            // operand
629            $token_decoded = str_replace(array('OP', 'CP'), array('(', ')'), $token);
630            $parsed_ary[] = $token_decoded;
631        }
632    }
633    $parsed_ary = array_values(array_merge($parsed_ary, array_reverse($ope_stack)));
634
635    // cleanup: each double "NOT" in RPN array actually does nothing
636    $parsed_ary_count = count($parsed_ary);
637    for ($i = 1; $i < $parsed_ary_count; ++$i) {
638        if ($parsed_ary[$i] === 'NOT' && $parsed_ary[$i - 1] === 'NOT') {
639            unset($parsed_ary[$i], $parsed_ary[$i - 1]);
640        }
641    }
642    $parsed_ary = array_values($parsed_ary);
643
644    // build return value
645    $q = array();
646    $q['query']      = $query;
647    $q['parsed_str'] = $parsed_query;
648    $q['parsed_ary'] = $parsed_ary;
649
650    foreach ($q['parsed_ary'] as $token) {
651        if ($token[2] !== ':') continue;
652        $body = substr($token, 3);
653
654        switch (substr($token, 0, 3)) {
655            case 'N+:':
656                     $q['ns'][]        = $body; // for backward compatibility
657                     break;
658            case 'N-:':
659                     $q['notns'][]     = $body; // for backward compatibility
660                     break;
661            case 'W_:':
662                     $q['words'][]     = $body;
663                     break;
664            case 'W-:':
665                     $q['words'][]     = $body;
666                     $q['not'][]       = $body; // for backward compatibility
667                     break;
668            case 'W+:':
669                     $q['words'][]     = $body;
670                     $q['highlight'][] = str_replace('*', '', $body);
671                     $q['and'][]       = $body; // for backward compatibility
672                     break;
673            case 'P-:':
674                     $q['phrases'][]   = $body;
675                     break;
676            case 'P+:':
677                     $q['phrases'][]   = $body;
678                     $q['highlight'][] = str_replace('*', '', $body);
679                     break;
680        }
681    }
682    foreach (array('words', 'phrases', 'highlight', 'ns', 'notns', 'and', 'not') as $key) {
683        $q[$key] = empty($q[$key]) ? array() : array_values(array_unique($q[$key]));
684    }
685
686    return $q;
687}
688
689/**
690 * Transforms given search term into intermediate representation
691 *
692 * This function is used in ft_queryParser() and not for general purpose use.
693 *
694 * @author Kazutaka Miyasaka <kazmiya@gmail.com>
695 */
696function ft_termParser($term, &$stopwords, $consider_asian = true, $phrase_mode = false) {
697    $parsed = '';
698    if ($consider_asian) {
699        // successive asian characters need to be searched as a phrase
700        $words = preg_split('/('.IDX_ASIAN.'+)/u', $term, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
701        foreach ($words as $word) {
702            if (preg_match('/'.IDX_ASIAN.'/u', $word)) $phrase_mode = true;
703            $parsed .= ft_termParser($word, $stopwords, false, $phrase_mode);
704        }
705    } else {
706        $term_noparen = str_replace(array('(', ')'), ' ', $term);
707        $words = idx_tokenizer($term_noparen, $stopwords, true);
708
709        // W_: no need to highlight
710        if (empty($words)) {
711            $parsed = '()'; // important: do not remove
712        } elseif ($words[0] === $term) {
713            $parsed = '(W+:'.$words[0].')';
714        } elseif ($phrase_mode) {
715            $term_encoded = str_replace(array('(', ')'), array('OP', 'CP'), $term);
716            $parsed = '((W_:'.implode(')(W_:', $words).')(P+:'.$term_encoded.'))';
717        } else {
718            $parsed = '((W+:'.implode(')(W+:', $words).'))';
719        }
720    }
721    return $parsed;
722}
723
724//Setup VIM: ex: et ts=4 enc=utf-8 :
725