/**
* Stuff that only needs to be done once. Builds regular expressions and sorts the reserved words.
*/
protected static function init()
{
if (self::$init) {
return;
}
// Sort reserved word list from longest word to shortest, 3x faster than usort
$reservedMap = array_combine(self::$reserved, array_map('strlen', self::$reserved));
arsort($reservedMap);
self::$reserved = array_keys($reservedMap);
// Set up regular expressions
self::$regex_boundaries = '(' . implode('|', array_map(array(__CLASS__, 'quote_regex'), self::$boundaries)) . ')';
self::$regex_reserved = '(' . implode('|', array_map(array(__CLASS__, 'quote_regex'), self::$reserved)) . ')';
self::$regex_reserved_toplevel = str_replace(' ', '\\s+', '(' . implode('|', array_map(array(__CLASS__, 'quote_regex'), self::$reserved_toplevel)) . ')');
self::$regex_reserved_newline = str_replace(' ', '\\s+', '(' . implode('|', array_map(array(__CLASS__, 'quote_regex'), self::$reserved_newline)) . ')');
self::$regex_function = '(' . implode('|', array_map(array(__CLASS__, 'quote_regex'), self::$functions)) . ')';
self::$init = true;
}