Scala example source code file (Product.scala)

This example Scala source code file (Product.scala) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Scala by Example" ^TM.

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Java - Scala tags/keywords

foldable1, productfunctor, traverse1

The Product.scala Scala example source code

package scalaz

import std.option.cata

private trait ProductFunctor[F[_], G[_]] extends Functor[λ[α => (F[α], G[α])]] {
  implicit def F: Functor[F]

  implicit def G: Functor[G]

  override def map[A, B](fa: (F[A], G[A]))(f: A => B): (F[B], G[B]) = (F.map(fa._1)(f), G.map(fa._2)(f))
}

private trait ProductApply[F[_], G[_]] extends Apply[λ[α => (F[α], G[α])]] with ProductFunctor[F, G] {
  implicit def F: Apply[F]

  implicit def G: Apply[G]

  override def ap[A, B](fa: => (F[A], G[A]))(f: => (F[A => B], G[A => B])): (F[B], G[B]) =
    (F.ap(fa._1)(f._1), G.ap(fa._2)(f._2))
}

private trait ProductApplicative[F[_], G[_]] extends Applicative[λ[α => (F[α], G[α])]] with ProductApply[F, G] {
  implicit def F: Applicative[F]

  implicit def G: Applicative[G]

  def point[A](a: => A): (F[A], G[A]) = (F.point(a), G.point(a))
}

private trait ProductBind[F[_], G[_]] extends Bind[λ[α => (F[α], G[α])]] with ProductApply[F, G] {
  implicit def F: Bind[F]

  implicit def G: Bind[G]

  override def bind[A, B](fa: (F[A], G[A]))(f: A => (F[B], G[B])) =
    (F.bind(fa._1)(f.andThen(_._1)), G.bind(fa._2)(f.andThen(_._2)))
}

private trait ProductBindRec[F[_], G[_]] extends BindRec[λ[α => (F[α], G[α])]] with ProductBind[F, G] {
  implicit def F: BindRec[F]

  implicit def G: BindRec[G]

  override def tailrecM[A, B](f: A => (F[A \/ B], G[A \/ B]))(a: A) =
    (F.tailrecM(f.andThen(_._1))(a), G.tailrecM(f.andThen(_._2))(a))
}

private trait ProductMonad[F[_], G[_]] extends Monad[λ[α => (F[α], G[α])]] with ProductBind[F, G] with ProductApplicative[F, G] {
  implicit def F: Monad[F]

  implicit def G: Monad[G]
}

private trait ProductPlus[F[_], G[_]] extends Plus[λ[α => (F[α], G[α])]] {
  implicit def F: Plus[F]

  implicit def G: Plus[G]

  def plus[A](a: (F[A], G[A]), b: => (F[A], G[A])): (F[A], G[A]) =
    (F.plus(a._1, b._1), G.plus(a._2, b._2))
}

private trait ProductPlusEmpty[F[_], G[_]] extends PlusEmpty[λ[α => (F[α], G[α])]] with ProductPlus[F, G] {
  implicit def F: PlusEmpty[F]

  implicit def G: PlusEmpty[G]

  def empty[A]: (F[A], G[A]) = (F.empty[A], G.empty[A])
}

private trait ProductApplicativePlus[F[_], G[_]] extends ApplicativePlus[λ[α => (F[α], G[α])]] with ProductApplicative[F, G] with ProductPlusEmpty[F, G] {
  implicit def F: ApplicativePlus[F]

  implicit def G: ApplicativePlus[G]
}

private trait ProductMonadPlus[F[_], G[_]] extends MonadPlus[λ[α => (F[α], G[α])]] with ProductApplicativePlus[F, G] with ProductMonad[F, G] {
  implicit def F: MonadPlus[F]

  implicit def G: MonadPlus[G]
}

private trait ProductFoldable[F[_], G[_]] extends Foldable[λ[α => (F[α], G[α])]] {
  implicit def F: Foldable[F]

  implicit def G: Foldable[G]

  override def foldRight[A, B](fa: (F[A], G[A]), z: => B)(f: (A, => B) => B): B =
    F.foldRight(fa._1, G.foldRight(fa._2, z)(f))(f)

  override def foldMap[A,B](fa: (F[A], G[A]))(f: A => B)(implicit M: Monoid[B]): B =
    M.append(F.foldMap(fa._1)(f), G.foldMap(fa._2)(f))

  override def foldLeft[A, B](fa: (F[A], G[A]), z: B)(f: (B, A) => B): B =
    G.foldLeft(fa._2, F.foldLeft(fa._1, z)(f))(f)
}

private trait ProductFoldable1L[F[_], G[_]] extends Foldable1[λ[α => (F[α], G[α])]] with ProductFoldable[F, G] {
  implicit def F: Foldable1[F]

  override def foldMapRight1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (A, => B) => B): B =
    cata(G.foldMapRight1Opt(fa._2)(z)(f))(F.foldRight(fa._1, _)(f), F.foldMapRight1(fa._1)(z)(f))

  override def foldMap1[A,B](fa: (F[A], G[A]))(f: A => B)(implicit S: Semigroup[B]): B = {
    val resume = F.foldMap1(fa._1)(f)
    cata(G.foldMap1Opt(fa._2)(f))(S.append(resume, _), resume)
  }

  override def foldMapLeft1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (B, A) => B): B =
    G.foldLeft(fa._2, F.foldMapLeft1(fa._1)(z)(f))(f)
}

private trait ProductFoldable1R[F[_], G[_]] extends Foldable1[λ[α => (F[α], G[α])]] with ProductFoldable[F, G] {
  implicit def G: Foldable1[G]

  override def foldMapRight1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (A, => B) => B): B =
    F.foldRight(fa._1, G.foldMapRight1(fa._2)(z)(f))(f)

  override def foldMap1[A,B](fa: (F[A], G[A]))(f: A => B)(implicit S: Semigroup[B]): B = {
    def resume = G.foldMap1(fa._2)(f)
    cata(F.foldMap1Opt(fa._1)(f))(S.append(_, resume), resume)
  }

  override def foldMapLeft1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (B, A) => B): B =
    cata(F.foldMapLeft1Opt(fa._1)(z)(f))(G.foldLeft(fa._2, _)(f), G.foldMapLeft1(fa._2)(z)(f))
}

private trait ProductFoldable1[F[_], G[_]] extends Foldable1[λ[α => (F[α], G[α])]] with ProductFoldable[F, G] {
  implicit def F: Foldable1[F]

  implicit def G: Foldable1[G]

  override def foldMapRight1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (A, => B) => B): B =
    F.foldRight(fa._1, G.foldMapRight1(fa._2)(z)(f))(f)

  override def foldMap1[A,B](fa: (F[A], G[A]))(f: A => B)(implicit S: Semigroup[B]): B =
    S.append(F.foldMap1(fa._1)(f), G.foldMap1(fa._2)(f))

  override def foldMapLeft1[A, B](fa: (F[A], G[A]))(z: A => B)(f: (B, A) => B): B =
    G.foldLeft(fa._2, F.foldMapLeft1(fa._1)(z)(f))(f)
}

private trait ProductTraverse[F[_], G[_]] extends Traverse[λ[α => (F[α], G[α])]] with ProductFunctor[F, G] with ProductFoldable[F, G] {
  implicit def F: Traverse[F]

  implicit def G: Traverse[G]

  def traverseImpl[X[_]:Applicative, A, B](a: (F[A], G[A]))(f: A => X[B]): X[(F[B], G[B])] =
    Applicative[X].tuple2(F.traverse(a._1)(f), G.traverse(a._2)(f))
}

private trait ProductTraverse1L[F[_], G[_]] extends Traverse1[λ[α => (F[α], G[α])]] with ProductFoldable1L[F, G] with ProductTraverse[F, G] {
  implicit def F: Traverse1[F]

  def traverse1Impl[X[_], A, B](a: (F[A], G[A]))(f: A => X[B])(implicit X0: Apply[X]): X[(F[B], G[B])] = {
    def resume = F.traverse1(a._1)(f)
    X0.applyApplicative.traverse(a._2)(f andThen \/.left)(G)
      .fold(X0.tuple2(resume, _),
            pr => X0.map(resume)((_, pr)))
  }

  override def traverseImpl[X[_]:Applicative, A, B](a: (F[A], G[A]))(f: A => X[B]): X[(F[B], G[B])] =
    super[ProductTraverse].traverseImpl(a)(f)
}

private trait ProductTraverse1R[F[_], G[_]] extends Traverse1[λ[α => (F[α], G[α])]] with ProductFoldable1R[F, G] with ProductTraverse[F, G] {
  implicit def G: Traverse1[G]

  def traverse1Impl[X[_], A, B](a: (F[A], G[A]))(f: A => X[B])(implicit X0: Apply[X]): X[(F[B], G[B])] = {
    def resume = G.traverse1(a._2)(f)
    X0.applyApplicative.traverse(a._1)(f andThen \/.left)(F)
      .fold(X0.tuple2(_, resume),
            pr => X0.map(resume)((pr, _)))
  }

  override def traverseImpl[X[_]:Applicative, A, B](a: (F[A], G[A]))(f: A => X[B]): X[(F[B], G[B])] =
    super[ProductTraverse].traverseImpl(a)(f)
}

private trait ProductTraverse1[F[_], G[_]] extends Traverse1[λ[α => (F[α], G[α])]] with ProductFoldable1[F, G] with ProductTraverse[F, G] {
  implicit def F: Traverse1[F]

  implicit def G: Traverse1[G]

  def traverse1Impl[X[_]:Apply, A, B](a: (F[A], G[A]))(f: A => X[B]): X[(F[B], G[B])] =
    Apply[X].tuple2(F.traverse1(a._1)(f), G.traverse1(a._2)(f))

  override def traverseImpl[X[_]:Applicative, A, B](a: (F[A], G[A]))(f: A => X[B]): X[(F[B], G[B])] =
    super[ProductTraverse].traverseImpl(a)(f)
}

private trait ProductDistributive[F[_], G[_]] extends Distributive[λ[α => (F[α], G[α])]] with ProductFunctor[F, G] {
  implicit def F: Distributive[F]

  implicit def G: Distributive[G]

  def distributeImpl[X[_]:Functor, A, B](a: X[A])(f: A => (F[B], G[B])): (F[X[B]], G[X[B]]) =
    (F.distribute(a)(x => f(x)._1), G.distribute(a)(x => f(x)._2))
}

private trait ProductAlign[F[_], G[_]] extends Align[λ[α => (F[α], G[α])]] with ProductFunctor[F, G] {
  implicit def F: Align[F]

  implicit def G: Align[G]

  def alignWith[A, B, C](f: (A \&/ B) => C): ((F[A], G[A]), (F[B], G[B])) => (F[C], G[C]) = {
    case ((fa, ga), (fb, gb)) => (F.alignWith(f)(fa, fb), G.alignWith(f)(ga, gb))
  }
}

private trait ProductZip[F[_], G[_]] extends Zip[λ[α => (F[α], G[α])]] {
  implicit def F: Zip[F]

  implicit def G: Zip[G]

  def zip[A, B](a: => (F[A], G[A]), b: => (F[B], G[B])): (F[(A, B)], G[(A, B)]) =
    (F.zip(a._1, b._1), G.zip(a._2, b._2))
}

private trait ProductUnzip[F[_], G[_]] extends Unzip[λ[α => (F[α], G[α])]] {
  implicit def F: Unzip[F]

  implicit def G: Unzip[G]

  def unzip[A, B](x: (F[(A, B)], G[(A, B)])): ((F[A], G[A]), (F[B], G[B])) = {
    val (fa, fb) = F.unzip(x._1)
    val (ga, gb) = G.unzip(x._2)
    ((fa, ga), (fb, gb))
  }
}

private trait ProductBifunctor[F[_, _], G[_, _]] extends Bifunctor[λ[(α, β) => (F[α, β], G[α, β])]] {
  implicit def F: Bifunctor[F]

  implicit def G: Bifunctor[G]

  override def bimap[A, B, C, D](fab: (F[A, B], G[A, B]))(f: A => C, g: B => D): (F[C, D], G[C, D]) =
    (F.bimap(fab._1)(f, g), G.bimap(fab._2)(f, g))
}

private trait ProductBifoldable[F[_, _], G[_, _]] extends Bifoldable[λ[(α, β) => (F[α, β], G[α, β])]] {
  implicit def F: Bifoldable[F]

  implicit def G: Bifoldable[G]

  override def bifoldMap[A,B,M](fa: (F[A, B], G[A, B]))(f: A => M)(g: B => M)(implicit M: Monoid[M]): M =
    M.append(F.bifoldMap(fa._1)(f)(g), G.bifoldMap(fa._2)(f)(g))
  override def bifoldRight[A,B,C](fa: (F[A, B], G[A, B]), z: => C)(f: (A, => C) => C)(g: (B, => C) => C): C =
    F.bifoldRight(fa._1, G.bifoldRight(fa._2, z)(f)(g))(f)(g)
  override def bifoldLeft[A,B,C](fa: (F[A, B], G[A, B]), z: C)(f: (C, A) => C)(g: (C, B) => C): C =
    G.bifoldLeft( fa._2, F.bifoldLeft( fa._1, z)(f)(g))(f)(g)
}

private trait ProductBitraverse[F[_, _], G[_, _]]
  extends Bitraverse[λ[(α, β) => (F[α, β], G[α, β])]] with ProductBifunctor[F, G] with ProductBifoldable[F, G] {

  implicit def F: Bitraverse[F]

  implicit def G: Bitraverse[G]

  def bitraverseImpl[X[_] : Applicative, A, B, C, D](x: (F[A, B], G[A, B]))(f: A => X[C], g: B => X[D]): X[(F[C, D], G[C, D])] =
    Applicative[X].tuple2(F.bitraverse(x._1)(f)(g), G.bitraverse(x._2)(f)(g))
}