public static function parse_sorter($text)
{
if (!self::$_sort_keywords) {
self::$_sort_keywords = array("by" => "by", "up" => "up", "down" => "down", "reverse" => "down", "reversed" => "down", "count" => "C", "counts" => "C", "av" => "A", "ave" => "A", "average" => "A", "med" => "E", "median" => "E", "var" => "V", "variance" => "V", "max-min" => "D", "my" => "Y", "score" => "");
}
$text = simplify_whitespace($text);
$sort = ListSorter::make_empty($text === "");
if (($ch1 = substr($text, 0, 1)) === "-" || $ch1 === "+") {
$sort->reverse = $ch1 === "-";
$text = ltrim(substr($text, 1));
}
// separate text into words
$words = array();
$bypos = false;
while ($text !== "") {
preg_match(',\\A([^\\s\\(]*)(.*)\\z,s', $text, $m);
if (substr($m[2], 0, 1) === "(") {
$pos = self::find_end_balanced_parens($m[2]);
$m[1] .= substr($m[2], 0, $pos);
$m[2] = substr($m[2], $pos);
}
$words[] = $m[1];
$text = ltrim($m[2]);
if ($m[1] === "by" && $bypos === false) {
$bypos = count($words) - 1;
}
}
// go over words
$next_words = array();
for ($i = 0; $i != count($words); ++$i) {
$w = $words[$i];
if (($bypos === false || $i > $bypos) && isset(self::$_sort_keywords[$w])) {
$x = self::$_sort_keywords[$w];
if ($x === "up") {
$sort->reverse = false;
} else {
if ($x === "down") {
$sort->reverse = true;
} else {
if (ctype_upper($x)) {
$sort->score = $x;
}
}
}
} else {
if ($bypos === false || $i < $bypos) {
$next_words[] = $w;
}
}
}
if (count($next_words)) {
$sort->type = join(" ", $next_words);
}
return $sort;
}
