Maybe and Either

funky.ooc

MaybeState: enum {
    None,
    Some
}

Maybe: class <T> {
    _value: T
    value: T {
        get {
            if(state == MaybeState None) raise("No value!")
            _value
        }
        set(=_value) {
            state = MaybeState Some
        }
    }

    state: MaybeState = MaybeState None
    init: func ~none {}

    init: func ~some (=_value) {
        state = MaybeState Some
    }

    hasSome?: func -> Bool { state == MaybeState Some }
}

Either: class <T, V> {
    _left: Maybe<T>
    _right: Maybe<V>

    init: func ~left (l: T) { _left value = l }
    init: func ~right (r: V) { _right value = r }

    left?: func -> Bool { _left hasSome?() }
    right?: func -> Bool { _right hasSome?() }

    left: func -> T { _left value }
    right: func -> V { _right value }
}