protected function walk($in_parent_id, $in_term_index)
{
/* check search depth to prevent infinite recursion */
$this->search_depth++;
if ($this->search_depth > JxBotEngine::MAX_SEARCH_DEPTH) {
throw new Exception('Too much recursion (in pattern search)');
}
/* look in this branch for all possible matching sub-branches;
ie. an exact match with the input term, or, a wildcard or complex pattern term
such as a bot property or AIML 2 'set' */
$stmt = JxBotDB::$db->prepare("SELECT id,expression,is_terminal FROM pattern_node \n\t\t\tWHERE parent=? AND ( (expression = ? AND sort_key IN (0,5)) OR (sort_key NOT IN (0,5)) ) \n\t\t\tORDER BY sort_key");
$current_term = $this->get_term($in_term_index);
$stmt->execute(array($in_parent_id, $current_term));
$possible_branches = $stmt->fetchAll(PDO::FETCH_NUM);
//print "Walk parent=$in_parent_id, term_index=$in_term_index, term=$current_term<br>";
//print '<pre>';
//var_dump($possible_branches);
//print '</pre>';
foreach ($possible_branches as $possibility) {
/* decode the possibility and prepare to match */
list($br_parent, $br_expr, $br_terminal) = $possibility;
// in future, for speed, this information could be assessed at pattern registration
// and stored & accessed, possibly using the sort key integer ?
$is_wildcard = JxBotEngine::is_wildcard($br_expr);
$set_ref = JxBotEngine::is_set_ref($br_expr);
$bot_ref = JxBotEngine::is_bot_ref($br_expr);
//print $br_expr;
//print "Considering possible branch=$br_parent, expr=$br_expr, term=$br_terminal, wild=$is_wildcard :<br>";
// pattern side sets & bot tags will have to be handled similarly, since they may have multi-word values
// basically, like wildcards, except all words must match
/* branch to appropriate match handler depending on type of branch */
if ($bot_ref !== false || $set_ref !== false) {
/* match: bot predicate or set reference: */
if ($bot_ref !== false) {
$values = array(JxBotNL::normalise(JxBotConfig::bot($bot_ref)));
$match = $this->try_match_values($br_parent, $values, false, $in_term_index, $br_terminal);
} else {
$values = JxBotNLData::set_values($set_ref);
$match = $this->try_match_values($br_parent, $values, true, $in_term_index, $br_terminal);
}
} else {
if (!$is_wildcard) {
/* match: normal word or pattern clause separator: */
$match = $this->try_match_word($br_parent, $br_expr, $in_term_index, $br_terminal);
} else {
/* match: wildcard */
$match = $this->try_match_wildcard($br_parent, $br_expr, $in_term_index, $br_terminal);
}
}
/* if matching was successful, return the matching pattern,
otherwise, continue looking at sub-branches at this level */
if ($match !== false) {
return $match;
}
}
/* no possible subbranches; no match this branch */
$this->search_depth--;
return false;
}
