function save_term_to_index($term, $hits, $docs_to_add, $index)
{
global $conn;
$docs_old = get_docs_from_index($term, $index);
$hits += count($docs_old);
foreach ($docs_to_add as $doc) {
//check if the docs that we found appear already in the posting
if (!in_array($doc, $docs_old)) {
//if not, edit
$docs_old[] = $doc;
}
}
$index[$term]["docs"] = $docs_old;
$index[$term]["hits"] = $hits;
return $index;
}
function search_words($q, $index)
{
global $total_docs;
global $stopwords;
global $operators_dictionary;
global $has_quotes;
$total_docs = get_docs_id();
$query_vars = explode(" ", $q);
//for every search word the user types change to lowercase
//check if surrounded with quotes
//if true remove them and update flag
//if false check they are in the stop words array
foreach ($query_vars as $key => $value) {
$token = strtolower($value);
if (mb_substr($token, 0, 1) != '"' && mb_substr($token, -1) != '"') {
$has_quotes = false;
if (in_array($token, $stopwords)) {
//in case of an operator command with a stop word
$query_vars = array_diff($query_vars, array('and', 'or', 'not', 'And', 'Or', 'Not', 'OR', 'AND', 'NOT'));
unset($query_vars[$key]);
continue;
}
} else {
$token = substr($token, 1, -1);
$has_quotes = true;
}
$query_vars[$key] = $token;
}
//transform in the correct order for a regular expression and validity of parentheses
$query_vars = convert_to_npr($query_vars);
if (empty($query_vars)) {
return array();
}
$added_docs = array();
//this is the docs of the synonyms
//foreach word in the search look up for the word and its synonyms
foreach ($query_vars as $token) {
if (!in_array($token, $operators_dictionary) || $has_quotes) {
$synonyms = get_synonyms($token);
//get all the synonyms word from a given term
if ($synonyms != NULL) {
//adds the synonyms words doc id from the current word
foreach ($synonyms as $synonym) {
$added_docs[] = get_docs_from_index($synonym, $index);
}
}
//adds to temp index the id of the docs which the word given appear in
$temp_index[] = array("term" => $token, "docs" => get_docs_from_index($token, $index));
} else {
$temp_index[] = array("term" => $token, "docs" => null);
}
}
//create the expression tree in which every intersection represent a boolean operator
//and every leaf represents a word
$root = create_tree(new ArrayIterator($temp_index));
$result = $root->evaluate();
//adds the synonyms docs for final search
foreach ($added_docs as $doc) {
foreach ($doc as $d) {
$result[] = $d;
}
}
$docs = array();
foreach ($result as $id) {
$docs[$id] = get_doc_details($id);
}
return $docs;
}
