module Std::Option {
    import Std::Io::{PrintLine};

    extern func bux_exit(code: int);

    enum Option<T> {
        Some(T),
        None,
    }

    func Option_NewSome<T>(value: T) -> Option<T> {
        let o: Option<T> = Option { tag: Option_Some };
        o.data.Some_0 = value;
        return o;
    }

    func Option_NewNone<T>() -> Option<T> {
        return Option { tag: Option_None };
    }

    func Option_IsSome<T>(o: Option<T>) -> bool {
        return o.tag == Option_Some;
    }

    func Option_IsNone<T>(o: Option<T>) -> bool {
        return o.tag == Option_None;
    }

    func Option_Unwrap<T>(o: Option<T>) -> T {
        if o.tag != Option_Some {
            PrintLine("panic: unwrap on None");
            bux_exit(1);
        }
        return o.data.Some_0;
    }

    func Option_UnwrapOr<T>(o: Option<T>, fallback: T) -> T {
        if o.tag == Option_Some {
            return o.data.Some_0;
        }
        return fallback;
    }

    func Option_Expect<T>(o: Option<T>, msg: String) -> T {
        if o.tag != Option_Some {
            PrintLine(msg);
            bux_exit(1);
        }
        return o.data.Some_0;
    }

    func Option_Or<T>(o: Option<T>, other: Option<T>) -> Option<T> {
        if o.tag == Option_Some {
            return o;
        }
        return other;
    }

}