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The Semialign type class represents functors supporting a zip operation that takes the union of non-uniform shapes.

Semialign instances are required to satisfy the following laws:

  1. F.align(fa, fa) = F.map(fa, (a) => both(a, a))
  2. F.align(F.map(fa, f), F.map(fb, g)) = F.map(F.align(fa, fb), (t) => These.bimap(t, f, g))
  3. F.alignWith(fa, fb, f) = F.map(F.align(fa, fb), f)
  4. F.align(fa, F.align(fb, fc)) = F.map(F.align(F.align(fa, fb), fc), These.assoc)

Where These.assoc implements the associativity law of These and has the following type signature: function assoc<A, B, C>(fa: These<A, These<B, C>>): These<These<A, B>, C>

Adapted from http://hackage.haskell.org/package/these-0.8/docs/Data-Align.html

Added in v0.1.0

Table of contents

utils

Semialign (interface)

Signature

export interface Semialign<F> extends Functor<F> {
  readonly align: <A, B>(fa: HKT<F, A>, fb: HKT<F, B>) => HKT<F, These<A, B>>
  readonly alignWith: <A, B, C>(fa: HKT<F, A>, fb: HKT<F, B>, f: (x: These<A, B>) => C) => HKT<F, C>
}

Added in v0.1.0

Semialign1 (interface)

Signature

export interface Semialign1<F extends URIS> extends Functor1<F> {
  readonly align: <A, B>(fa: Kind<F, A>, fb: Kind<F, B>) => Kind<F, These<A, B>>
  readonly alignWith: <A, B, C>(fa: Kind<F, A>, fb: Kind<F, B>, f: (x: These<A, B>) => C) => Kind<F, C>
}

Added in v0.1.0

Semialign2 (interface)

Signature

export interface Semialign2<F extends URIS2> extends Functor2<F> {
  readonly align: <L, A, B>(fa: Kind2<F, L, A>, fb: Kind2<F, L, B>) => Kind2<F, L, These<A, B>>
  readonly alignWith: <L, A, B, C>(fa: Kind2<F, L, A>, fb: Kind2<F, L, B>, f: (x: These<A, B>) => C) => Kind2<F, L, C>
}

Added in v0.1.0

Semialign2C (interface)

Signature

export interface Semialign2C<F extends URIS2, L> extends Functor2C<F, L> {
  readonly align: <A, B>(fa: Kind2<F, L, A>, fb: Kind2<F, L, B>) => Kind2<F, L, These<A, B>>
  readonly alignWith: <A, B, C>(fa: Kind2<F, L, A>, fb: Kind2<F, L, B>, f: (x: These<A, B>) => C) => Kind2<F, L, C>
}

Added in v0.1.0

Semialign3 (interface)

Signature

export interface Semialign3<F extends URIS3> extends Functor3<F> {
  readonly align: <U, L, A, B>(fa: Kind3<F, U, L, A>, fb: Kind3<F, U, L, B>) => Kind3<F, U, L, These<A, B>>
  readonly alignWith: <U, L, A, B, C>(
    fa: Kind3<F, U, L, A>,
    fb: Kind3<F, U, L, B>,
    f: (x: These<A, B>) => C
  ) => Kind3<F, U, L, C>
}

Added in v0.1.0