function chooseFile($fname = null)
{
if (!self::$operatorString) {
self::$operatorString = '(' . implode('|', array_map(array($this, 'preg_quote'), array_keys(self::$precedence))) . ')';
}
if ($fname) {
if (!is_file($fname)) {
throw new Exception('load error: failed to find ' . $fname);
}
$pi = pathinfo($fname);
$this->fileName = $fname;
$this->importDir = $pi['dirname'] . '/';
$this->buffer = file_get_contents($fname);
}
}
