model

export interface Unfoldable<F> {
  readonly URI: F
  readonly unfold: <A, B>(b: B, f: (b: B) => Option<[A, B]>) => HKT<F, A>
}

export interface Unfoldable1<F extends URIS> {
  readonly URI: F
  readonly unfold: <A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind<F, A>
}

export interface Unfoldable2<F extends URIS2> {
  readonly URI: F
  readonly unfold: <E, A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind2<F, E, A>
}

export interface Unfoldable2C<F extends URIS2, E> {
  readonly URI: F
  readonly _E: E
  readonly unfold: <A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind2<F, E, A>
}

export interface Unfoldable3<F extends URIS3> {
  readonly URI: F
  readonly unfold: <R, E, A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind3<F, R, E, A>
}

export interface Unfoldable3C<F extends URIS3, E> {
  readonly URI: F
  readonly _E: E
  readonly unfold: <R, A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind3<F, R, E, A>
}

export interface Unfoldable4<F extends URIS4> {
  readonly URI: F
  readonly unfold: <S, R, E, A, B>(b: B, f: (b: B) => Option<[A, B]>) => Kind4<F, S, R, E, A>
}