--- /dev/null
+<?php // $Id$
+
+///////////////////////////////////////////////////////////////////////////
+// //
+// NOTICE OF COPYRIGHT //
+// //
+// Original code: //
+// //
+// Drupal - The copyright of both the Drupal software and the //
+// "Druplicon" logo belongs to all the original authors, //
+// though both are licensed under the GPL. //
+// http://drupal.org //
+// //
+// Modifications: //
+// //
+// Moodle - Modular Object-Oriented Dynamic Learning Environment //
+// http://moodle.com //
+// //
+// Copyright (C) 2001-3001 Martin Dougiamas http://dougiamas.com //
+// (C) 2001-3001 Eloy Lafuente (stronk7) http://contiento.com //
+// (C) 2001-3001 Antonio Vicent http://ludens.es //
+// //
+// This program 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 of the License, or //
+// (at your option) any later version. //
+// //
+// This program 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: //
+// //
+// http://www.gnu.org/copyleft/gpl.html //
+// //
+///////////////////////////////////////////////////////////////////////////
+
+/// Based on Drupal's search.module version 1.224
+/// http://cvs.drupal.org/viewcvs/drupal/drupal/modules/search/search.module?view=markup
+
+/// Usage: $tokens = tokenise_text($text)
+/// Returns an array of tokens (key) with their score (value)
+/// (see function definition for more info)
+
+/// Some constants
+
+define ('MINIMUM_WORD_SIZE', 3); /// Minimum word size to index and search
+define ('MAXIMUM_WORD_SIZE', 50); /// Maximum word size to index and search
+
+define ('START_DELIM', "\xce\xa9\xc3\x91\xc3\x91"); // Use these (omega) and (ntilde) utf-8 combinations
+define ('CENTER_DELIM', "\xc3\x91\xce\xa9\xc3\x91"); // as safe delimiters (not puncuation nor usual) while
+define ('END_DELIM', "\xc3\x91\xc3\x91\xce\xa9"); // processing numbers ($join_numbers = false)
+
+/**
+ * Matches Unicode character classes to exclude from the search index.
+ *
+ * See: http://www.unicode.org/Public/UNIDATA/UCD.html#General_Category_Values
+ *
+ * The index only contains the following character classes:
+ * Lu Letter, Uppercase
+ * Ll Letter, Lowercase
+ * Lt Letter, Titlecase
+ * Lo Letter, Other
+ * Nd Number, Decimal Digit
+ * No Number, Other
+ */
+define('PREG_CLASS_SEARCH_EXCLUDE',
+'\x{0}-\x{2f}\x{3a}-\x{40}\x{5b}-\x{60}\x{7b}-\x{bf}\x{d7}\x{f7}\x{2b0}-'.
+'\x{385}\x{387}\x{3f6}\x{482}-\x{489}\x{559}-\x{55f}\x{589}-\x{5c7}\x{5f3}-'.
+'\x{61f}\x{640}\x{64b}-\x{65e}\x{66a}-\x{66d}\x{670}\x{6d4}\x{6d6}-\x{6ed}'.
+'\x{6fd}\x{6fe}\x{700}-\x{70f}\x{711}\x{730}-\x{74a}\x{7a6}-\x{7b0}\x{901}-'.
+'\x{903}\x{93c}\x{93e}-\x{94d}\x{951}-\x{954}\x{962}-\x{965}\x{970}\x{981}-'.
+'\x{983}\x{9bc}\x{9be}-\x{9cd}\x{9d7}\x{9e2}\x{9e3}\x{9f2}-\x{a03}\x{a3c}-'.
+'\x{a4d}\x{a70}\x{a71}\x{a81}-\x{a83}\x{abc}\x{abe}-\x{acd}\x{ae2}\x{ae3}'.
+'\x{af1}-\x{b03}\x{b3c}\x{b3e}-\x{b57}\x{b70}\x{b82}\x{bbe}-\x{bd7}\x{bf0}-'.
+'\x{c03}\x{c3e}-\x{c56}\x{c82}\x{c83}\x{cbc}\x{cbe}-\x{cd6}\x{d02}\x{d03}'.
+'\x{d3e}-\x{d57}\x{d82}\x{d83}\x{dca}-\x{df4}\x{e31}\x{e34}-\x{e3f}\x{e46}-'.
+'\x{e4f}\x{e5a}\x{e5b}\x{eb1}\x{eb4}-\x{ebc}\x{ec6}-\x{ecd}\x{f01}-\x{f1f}'.
+'\x{f2a}-\x{f3f}\x{f71}-\x{f87}\x{f90}-\x{fd1}\x{102c}-\x{1039}\x{104a}-'.
+'\x{104f}\x{1056}-\x{1059}\x{10fb}\x{10fc}\x{135f}-\x{137c}\x{1390}-\x{1399}'.
+'\x{166d}\x{166e}\x{1680}\x{169b}\x{169c}\x{16eb}-\x{16f0}\x{1712}-\x{1714}'.
+'\x{1732}-\x{1736}\x{1752}\x{1753}\x{1772}\x{1773}\x{17b4}-\x{17db}\x{17dd}'.
+'\x{17f0}-\x{180e}\x{1843}\x{18a9}\x{1920}-\x{1945}\x{19b0}-\x{19c0}\x{19c8}'.
+'\x{19c9}\x{19de}-\x{19ff}\x{1a17}-\x{1a1f}\x{1d2c}-\x{1d61}\x{1d78}\x{1d9b}-'.
+'\x{1dc3}\x{1fbd}\x{1fbf}-\x{1fc1}\x{1fcd}-\x{1fcf}\x{1fdd}-\x{1fdf}\x{1fed}-'.
+'\x{1fef}\x{1ffd}-\x{2070}\x{2074}-\x{207e}\x{2080}-\x{2101}\x{2103}-\x{2106}'.
+'\x{2108}\x{2109}\x{2114}\x{2116}-\x{2118}\x{211e}-\x{2123}\x{2125}\x{2127}'.
+'\x{2129}\x{212e}\x{2132}\x{213a}\x{213b}\x{2140}-\x{2144}\x{214a}-\x{2b13}'.
+'\x{2ce5}-\x{2cff}\x{2d6f}\x{2e00}-\x{3005}\x{3007}-\x{303b}\x{303d}-\x{303f}'.
+'\x{3099}-\x{309e}\x{30a0}\x{30fb}-\x{30fe}\x{3190}-\x{319f}\x{31c0}-\x{31cf}'.
+'\x{3200}-\x{33ff}\x{4dc0}-\x{4dff}\x{a015}\x{a490}-\x{a716}\x{a802}\x{a806}'.
+'\x{a80b}\x{a823}-\x{a82b}\x{d800}-\x{f8ff}\x{fb1e}\x{fb29}\x{fd3e}\x{fd3f}'.
+'\x{fdfc}-\x{fe6b}\x{feff}-\x{ff0f}\x{ff1a}-\x{ff20}\x{ff3b}-\x{ff40}\x{ff5b}-'.
+'\x{ff65}\x{ff70}\x{ff9e}\x{ff9f}\x{ffe0}-\x{fffd}');
+
+/**
+ * Matches all 'N' Unicode character classes (numbers)
+ */
+define('PREG_CLASS_NUMBERS',
+'\x{30}-\x{39}\x{b2}\x{b3}\x{b9}\x{bc}-\x{be}\x{660}-\x{669}\x{6f0}-\x{6f9}'.
+'\x{966}-\x{96f}\x{9e6}-\x{9ef}\x{9f4}-\x{9f9}\x{a66}-\x{a6f}\x{ae6}-\x{aef}'.
+'\x{b66}-\x{b6f}\x{be7}-\x{bf2}\x{c66}-\x{c6f}\x{ce6}-\x{cef}\x{d66}-\x{d6f}'.
+'\x{e50}-\x{e59}\x{ed0}-\x{ed9}\x{f20}-\x{f33}\x{1040}-\x{1049}\x{1369}-'.
+'\x{137c}\x{16ee}-\x{16f0}\x{17e0}-\x{17e9}\x{17f0}-\x{17f9}\x{1810}-\x{1819}'.
+'\x{1946}-\x{194f}\x{2070}\x{2074}-\x{2079}\x{2080}-\x{2089}\x{2153}-\x{2183}'.
+'\x{2460}-\x{249b}\x{24ea}-\x{24ff}\x{2776}-\x{2793}\x{3007}\x{3021}-\x{3029}'.
+'\x{3038}-\x{303a}\x{3192}-\x{3195}\x{3220}-\x{3229}\x{3251}-\x{325f}\x{3280}-'.
+'\x{3289}\x{32b1}-\x{32bf}\x{ff10}-\x{ff19}');
+
+/**
+ * Matches all 'P' Unicode character classes (punctuation)
+ */
+define('PREG_CLASS_PUNCTUATION',
+'\x{21}-\x{23}\x{25}-\x{2a}\x{2c}-\x{2f}\x{3a}\x{3b}\x{3f}\x{40}\x{5b}-\x{5d}'.
+'\x{5f}\x{7b}\x{7d}\x{a1}\x{ab}\x{b7}\x{bb}\x{bf}\x{37e}\x{387}\x{55a}-\x{55f}'.
+'\x{589}\x{58a}\x{5be}\x{5c0}\x{5c3}\x{5f3}\x{5f4}\x{60c}\x{60d}\x{61b}\x{61f}'.
+'\x{66a}-\x{66d}\x{6d4}\x{700}-\x{70d}\x{964}\x{965}\x{970}\x{df4}\x{e4f}'.
+'\x{e5a}\x{e5b}\x{f04}-\x{f12}\x{f3a}-\x{f3d}\x{f85}\x{104a}-\x{104f}\x{10fb}'.
+'\x{1361}-\x{1368}\x{166d}\x{166e}\x{169b}\x{169c}\x{16eb}-\x{16ed}\x{1735}'.
+'\x{1736}\x{17d4}-\x{17d6}\x{17d8}-\x{17da}\x{1800}-\x{180a}\x{1944}\x{1945}'.
+'\x{2010}-\x{2027}\x{2030}-\x{2043}\x{2045}-\x{2051}\x{2053}\x{2054}\x{2057}'.
+'\x{207d}\x{207e}\x{208d}\x{208e}\x{2329}\x{232a}\x{23b4}-\x{23b6}\x{2768}-'.
+'\x{2775}\x{27e6}-\x{27eb}\x{2983}-\x{2998}\x{29d8}-\x{29db}\x{29fc}\x{29fd}'.
+'\x{3001}-\x{3003}\x{3008}-\x{3011}\x{3014}-\x{301f}\x{3030}\x{303d}\x{30a0}'.
+'\x{30fb}\x{fd3e}\x{fd3f}\x{fe30}-\x{fe52}\x{fe54}-\x{fe61}\x{fe63}\x{fe68}'.
+'\x{fe6a}\x{fe6b}\x{ff01}-\x{ff03}\x{ff05}-\x{ff0a}\x{ff0c}-\x{ff0f}\x{ff1a}'.
+'\x{ff1b}\x{ff1f}\x{ff20}\x{ff3b}-\x{ff3d}\x{ff3f}\x{ff5b}\x{ff5d}\x{ff5f}-'.
+'\x{ff65}');
+
+/**
+ * Matches all CJK characters that are candidates for auto-splitting
+ * (Chinese, Japanese, Korean).
+ * Contains kana and BMP ideographs.
+ */
+define('PREG_CLASS_CJK', '\x{3041}-\x{30ff}\x{31f0}-\x{31ff}\x{3400}-\x{4db5}'.
+'\x{4e00}-\x{9fbb}\x{f900}-\x{fad9}');
+
+
+/**
+ * This function process the text passed at input, extracting all the tokens
+ * and scoring each one based in their number of ocurrences and relation with
+ * some well-known html tags
+ *
+ * @param string $text the text to be tokenised.
+ * @param array $stop_words array of utf-8 words than can be ignored in
+ * the text being processed. There are some cool lists of
+ * stop words at http://snowball.tartarus.org/
+ * @param boolean $overlap_cjk option to split CJK text into some overlapping
+ * tokens is order to allow them to be searched. Useful to build
+ * indexes and search systems.
+ * @param boolean $join_numbers option to join in one unique token sequences of numbers
+ * separated by puntuaction chars. Useful to build indexes and
+ * search systems.
+ * @return array one sorted array of tokens, with tokens being the keys and scores in the values.
+ */
+function tokenise_text($text, $stop_words = array(), $overlap_cjk = false, $join_numbers = false) {
+
+ $textlib = textlib_get_instance();
+
+ // Multipliers for scores of words inside certain HTML tags.
+ // Note: 'a' must be included for link ranking to work.
+ $tags = array('h1' => 25,
+ 'h2' => 18,
+ 'h3' => 15,
+ 'h4' => 12,
+ 'h5' => 9,
+ 'h6' => 6,
+ 'u' => 3,
+ 'b' => 3,
+ 'i' => 3,
+ 'strong' => 3,
+ 'em' => 3,
+ 'a' => 10);
+
+ // Strip off all ignored tags to speed up processing, but insert space before/after
+ // them to keep word boundaries.
+ $text = str_replace(array('<', '>'), array(' <', '> '), $text);
+ $text = strip_tags($text, '<'. implode('><', array_keys($tags)) .'>');
+
+ // Split HTML tags from plain text.
+ $split = preg_split('/\s*<([^>]+?)>\s*/', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
+ // Note: PHP ensures the array consists of alternating delimiters and literals
+ // and begins and ends with a literal (inserting $null as required).
+
+ $tag = FALSE; // Odd/even counter. Tag or no tag.
+ $score = 1; // Starting score per word
+ $accum = ' '; // Accumulator for cleaned up data
+ $tagstack = array(); // Stack with open tags
+ $tagwords = 0; // Counter for consecutive words
+ $focus = 1; // Focus state
+
+ $results = array(0 => array()); // Accumulator for words for index
+
+ foreach ($split as $value) {
+ if ($tag) {
+ // Increase or decrease score per word based on tag
+ list($tagname) = explode(' ', $value, 2);
+ $tagname = $textlib->strtolower($tagname);
+ // Closing or opening tag?
+ if ($tagname[0] == '/') {
+ $tagname = substr($tagname, 1);
+ // If we encounter unexpected tags, reset score to avoid incorrect boosting.
+ if (!count($tagstack) || $tagstack[0] != $tagname) {
+ $tagstack = array();
+ $score = 1;
+ }
+ else {
+ // Remove from tag stack and decrement score
+ $score = max(1, $score - $tags[array_shift($tagstack)]);
+ }
+ }
+ else {
+ if (isset($tagstack[0]) && $tagstack[0] == $tagname) {
+ // None of the tags we look for make sense when nested identically.
+ // If they are, it's probably broken HTML.
+ $tagstack = array();
+ $score = 1;
+ }
+ else {
+ // Add to open tag stack and increment score
+ array_unshift($tagstack, $tagname);
+ $score += $tags[$tagname];
+ }
+ }
+ // A tag change occurred, reset counter.
+ $tagwords = 0;
+ }
+ else {
+ // Note: use of PREG_SPLIT_DELIM_CAPTURE above will introduce empty values
+ if ($value != '') {
+ $words = tokenise_split($value, $stop_words, $overlap_cjk, $join_numbers);
+ foreach ($words as $word) {
+ // Add word to accumulator
+ $accum .= $word .' ';
+ $num = is_numeric($word);
+ // Check word length
+ if ($num || $textlib->strlen($word) >= MINIMUM_WORD_SIZE) {
+ // Normalize numbers
+ if ($num && $join_numbers) {
+ $word = (int)ltrim($word, '-0');
+ }
+
+ if (!isset($results[0][$word])) {
+ $results[0][$word] = 0;
+ }
+
+ $results[0][$word] += $score * $focus;
+ // Focus is a decaying value in terms of the amount of unique words up to this point.
+ // From 100 words and more, it decays, to e.g. 0.5 at 500 words and 0.3 at 1000 words.
+ $focus = min(1, .01 + 3.5 / (2 + count($results[0]) * .015));
+ }
+ $tagwords++;
+ // Too many words inside a single tag probably mean a tag was accidentally left open.
+ if (count($tagstack) && $tagwords >= 15) {
+ $tagstack = array();
+ $score = 1;
+ }
+ }
+ }
+ }
+ $tag = !$tag;
+ }
+
+ $res = array();
+
+ if (isset($results[0]) && count($results[0]) > 0) {
+ $res = $results[0];
+ arsort($res, SORT_NUMERIC);
+ }
+
+ return $res;
+}
+
+///
+/// Some helper functions (should be considered private)
+///
+
+/**
+ * Splits a string into tokens
+ */
+function tokenise_split($text, $stop_words, $overlap_cjk, $join_numbers) {
+ static $last = NULL;
+ static $lastsplit = NULL;
+
+ if ($last == $text) {
+ return $lastsplit;
+ }
+ // Process words
+ $text = tokenise_simplify($text, $overlap_cjk, $join_numbers);
+ $words = explode(' ', $text);
+ // Limit word length to 50
+ array_walk($words, 'tokenise_truncate_word');
+
+ // We have stop words, apply them
+ if (is_array($stop_words) && !empty($stop_words)) {
+ // Normalise them
+ $simp_stop_words = explode(' ', tokenise_simplify(implode(' ', $stop_words), $overlap_cjk, $join_numbers));
+ // Extract from the list
+ $words = array_diff($words, $simp_stop_words);
+ }
+ // Save last keyword result
+ $last = $text;
+ $lastsplit = $words;
+
+ return $words;
+}
+
+/**
+ * Simplifies a string according to indexing rules.
+ */
+function tokenise_simplify($text, $overlap_cjk, $join_numbers) {
+
+ $textlib = textlib_get_instance();
+
+ // Decode entities to UTF-8
+ $text = html_entity_decode($text, ENT_QUOTES, 'UTF-8');
+
+ // Lowercase
+ $text = $textlib->strtolower($text);
+
+ // Simple CJK handling
+ if ($overlap_cjk) {
+ $text = preg_replace_callback('/['. PREG_CLASS_CJK .']+/u', 'tokenise_expand_cjk', $text);
+ }
+
+ // To improve searching for numerical data such as dates, IP addresses
+ // or version numbers, we consider a group of numerical characters
+ // separated only by punctuation characters to be one piece.
+ // This also means that searching for e.g. '20/03/1984' also returns
+ // results with '20-03-1984' in them.
+ // Readable regexp: ([number]+)[punctuation]+(?=[number])
+ if ($join_numbers) {
+ $text = preg_replace('/(['. PREG_CLASS_NUMBERS .']+)['. PREG_CLASS_PUNCTUATION .']+(?=['. PREG_CLASS_NUMBERS .'])/u', '\1', $text);
+ } else {
+ // Keep all the detected numbers+punctuation in a safe place in order to restore them later
+ preg_match_all('/['. PREG_CLASS_NUMBERS .']+['. PREG_CLASS_PUNCTUATION . PREG_CLASS_NUMBERS .']+/u', $text, $foundseqs);
+ $storedseqs = array();
+ foreach (array_unique($foundseqs[0]) as $ntkey => $value) {
+ $prefix = (string)(count($storedseqs) + 1);
+ $storedseqs[START_DELIM.$prefix.CENTER_DELIM.$ntkey.END_DELIM] = $value;
+ }
+ if (!empty($storedseqs)) {
+ $text = str_replace($storedseqs, array_keys($storedseqs), $text);
+ }
+ }
+
+ // The dot, underscore and dash are simply removed. This allows meaningful
+ // search behaviour with acronyms and URLs.
+ $text = preg_replace('/[._-]+/', '', $text);
+
+ // With the exception of the rules above, we consider all punctuation,
+ // marks, spacers, etc, to be a word boundary.
+ $text = preg_replace('/['. PREG_CLASS_SEARCH_EXCLUDE .']+/u', ' ', $text);
+
+ // Restore, if not joining numbers, recover the original strings
+ if (!$join_numbers) {
+ if (!empty($storedseqs)) {
+ $text = str_replace(array_keys($storedseqs), $storedseqs, $text);
+ }
+ }
+
+ return $text;
+}
+
+/**
+ * Basic CJK tokeniser. Simply splits a string into consecutive, overlapping
+ * sequences of characters (MINIMUM_WORD_SIZE long).
+ */
+function tokenise_expand_cjk($matches) {
+
+ $textlib = textlib_get_instance();
+
+ $str = $matches[0];
+ $l = $textlib->strlen($str);
+ // Passthrough short words
+ if ($l <= MINIMUM_WORD_SIZE) {
+ return ' '. $str .' ';
+ }
+ $tokens = ' ';
+ // FIFO queue of characters
+ $chars = array();
+ // Begin loop
+ for ($i = 0; $i < $l; ++$i) {
+ // Grab next character
+ $current = $textlib->substr($str, 0, 1);
+ $str = substr($str, strlen($current));
+ $chars[] = $current;
+ if ($i >= MINIMUM_WORD_SIZE - 1) {
+ $tokens .= implode('', $chars) .' ';
+ array_shift($chars);
+ }
+ }
+ return $tokens;
+}
+
+/**
+ * Helper function for array_walk in search_index_split.
+ * Truncates one string (token) to MAXIMUM_WORD_SIZE
+ */
+function tokenise_truncate_word(&$text) {
+
+ $textlib = textlib_get_instance();
+ $text = $textlib->substr($text, 0, MAXIMUM_WORD_SIZE);
+}
+
+?>
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