funky

type Either[E, V any] interface {
	Maybe[V]
	IsLeft() bool
	IsRight() bool
	Left() E
	Right() V
}

type Iterable[V any] interface {
	Iterator() Iterator[V]
}

type Iterator[V any] interface {
	Maybe[V]
	Next() bool
	Value() V
	Walk(func(V))
}

type Map[K comparable, V any] interface {
	Iterable[MapItem[K, V]]
	Maybe[MapItem[K, V]]
	Sizeable
	Get(K) Maybe[V]
	Set(K, V)
	Delete(K)
	Keys() Iterator[K]
	Values() Iterator[V]
}

type MapItem[K comparable, V any] struct {
	Key   K
	Value V
}

type Maybe[V any] interface {
	IsNothing() bool
	Value() V
}

type Sizeable interface {
	Size() Maybe[int]
}