factN+1; for rules //the function takes a string with newline separated facts and rules and adds them to a knowledgebase function parse($input, $kb){ $lines = str_replace(" ", "", $line); $lines = str_replace("\n", "", $line); $lines = explode(";", $input); foreach($lines as $line){ //determine if the line is a fact or a rule if(!preg_match("/=>/", $line) && $line != ""){ //we have a candidate for a fact $fact = parseFact($line); $kb->add_fact($fact); } elseif($line != ""){ //we have a candidate for a rule $parts = preg_split("/=>/", $line); $horns = preg_split("/\\^/", $parts[0]); for($i = 0; $i < count($horns); $i++){ //echo($horns[i]); //echo("
"); $horns[$i] = parseFact($horns[$i]); } $head = parseFact($parts[1]); $rule = new rule($head, $horns); $kb->add_rule($rule); } } return $kb; } function parseFact($line){ $parts = preg_split("/\\(/", $line); $name = preg_replace('/\s+/', '', $parts[0]); $arguments = preg_split("/,\\s*/", $parts[1]); $objArgs = array(); for($i = 0; $i < count($arguments); $i++){ $arguments[$i] = str_replace(")", "", $arguments[$i]); $arguments[$i] = str_replace(" ", "", $arguments[$i]); if(contains("*", $arguments[$i])){ $objArgs[] = new variable($arguments[$i]); } else{ $objArgs[] = new atom($arguments[$i]); } } return new fact($name, $objArgs); } ?>