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Contravariant

3 exports Added in v0.24.0 Source

Other

contramapComposition

Added in v0.24.0 Source

Composing two contravariant functors yields a Covariant functor.

Returns a default binary map composition.

Signature

declare function contramapComposition<F extends TypeLambda, G extends TypeLambda>(
  F: Contravariant<F>,
  G: Contravariant<G>,
): <FR, FO, FE, GR, GO, GE, A, B>(
  self: Kind<F, FR, FO, FE, Kind<G, GR, GO, GE, A>>,
  f: (a: A) => B,
) => Kind<F, FR, FO, FE, Kind<G, GR, GO, GE, B>>;

imap

Added in v0.24.0 Source

Returns a default imap implementation.

Signature

declare function imap<F extends TypeLambda>(
  contramap: <R, O, E, A, B>(self: Kind<F, R, O, E, A>, f: (b: B) => A) => Kind<F, R, O, E, B>,
): {
  <A, B>(
    to: (a: A) => B,
    from: (b: B) => A,
  ): <R, O, E>(self: Kind<F, R, O, E, A>) => Kind<F, R, O, E, B>;
  <R, O, E, A, B>(
    self: Kind<F, R, O, E, A>,
    to: (a: A) => B,
    from: (b: B) => A,
  ): Kind<F, R, O, E, B>;
};

Type Class

Contravariant interface

Added in v0.24.0 Source

Signature

interface Contravariant<F extends TypeLambda> extends Invariant<F> {
  readonly contramap: {
    <B, A>(f: (b: B) => A): <R, O, E>(self: Kind<F, R, O, E, A>) => Kind<F, R, O, E, B>;
    <R, O, E, A, B>(self: Kind<F, R, O, E, A>, f: (b: B) => A): Kind<F, R, O, E, B>;
  };
}