public static bool from_str(bool self, string s)
{
if (s == "true" || s == "t" ||
s == "True" || s == "T" ||
s == "TRUE") {
return true;
}
else if (s == "false" || s == "f" ||
s == "False" || s == "F" ||
s == "FALSE") {
return false;
}
else {
throw new Exception("can't interpret bool value: " + s);
}
}