The Alt
type class identifies an associative operation on a type constructor. It is similar to Semigroup
, except
that it applies to types of kind * -> *
, like Array
or Option
, rather than concrete types like string
or
number
.
Alt
instances are required to satisfy the following laws:
A.alt(A.alt(fa, ga), ha) <-> A.alt(fa, A.alt(ga, ha))
A.map(A.alt(fa, ga), ab) <-> A.alt(A.map(fa, ab), A.map(ga, ab))
Added in v2.0.0
Signature
export interface Alt<F> extends Functor<F> {
readonly alt: <A>(fa: HKT<F, A>, that: Lazy<HKT<F, A>>) => HKT<F, A>
}
Added in v2.0.0
Signature
export interface Alt1<F extends URIS> extends Functor1<F> {
readonly alt: <A>(fa: Kind<F, A>, that: Lazy<Kind<F, A>>) => Kind<F, A>
}
Added in v2.0.0
Signature
export interface Alt2<F extends URIS2> extends Functor2<F> {
readonly alt: <E, A>(fa: Kind2<F, E, A>, that: Lazy<Kind2<F, E, A>>) => Kind2<F, E, A>
}
Added in v2.0.0
Signature
export interface Alt2C<F extends URIS2, E> extends Functor2C<F, E> {
readonly alt: <A>(fa: Kind2<F, E, A>, that: Lazy<Kind2<F, E, A>>) => Kind2<F, E, A>
}
Added in v2.0.0
Signature
export interface Alt3<F extends URIS3> extends Functor3<F> {
readonly alt: <R, E, A>(fa: Kind3<F, R, E, A>, that: Lazy<Kind3<F, R, E, A>>) => Kind3<F, R, E, A>
}
Added in v2.0.0
Signature
export interface Alt3C<F extends URIS3, E> extends Functor3C<F, E> {
readonly alt: <R, A>(fa: Kind3<F, R, E, A>, that: Lazy<Kind3<F, R, E, A>>) => Kind3<F, R, E, A>
}
Added in v2.2.0
Signature
export interface Alt4<F extends URIS4> extends Functor4<F> {
readonly alt: <S, R, E, A>(fa: Kind4<F, S, R, E, A>, that: Lazy<Kind4<F, S, R, E, A>>) => Kind4<F, S, R, E, A>
}
Added in v2.0.0