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Scala example source code file (StoreT.scala)

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

Learn more about this Scala project at its project page.

Java - Scala tags/keywords

comonad, functor, indexedstoret

The StoreT.scala Scala example source code

package scalaz

import Id._

 * @see [[scalaz.Lens]]
final case class IndexedStoreT[F[_], +I, A, B](run: (F[A => B], I)) {
  import StoreT._
  import BijectionT._

  def xmap[X1, X2](f: I => X1)(g: X2 => A)(implicit F: Functor[F]): IndexedStoreT[F, X1, X2, B] =
    indexedStoreT(( compose g), f(pos)))

  def bmap[X, Z >: I <: A](b: Bijection[Z, X])(implicit F: Functor[F]): StoreT[F, X, B] =
    xmap(b to _)(b from _)

  def imap[X](f: I => X): IndexedStoreT[F, X, A, B] =
    indexedStoreT((set, f(pos)))

  def contramap[X](g: X => A)(implicit F: Functor[F]) =
    indexedStoreT(( compose g), pos))

  def bimap[X, Y](f: I => X)(g: B => Y)(implicit F: Functor[F]): IndexedStoreT[F, X, A, Y] =
    indexedStoreT(( compose _), f(pos)))

  def leftMap[X](f: I => X): IndexedStoreT[F, X, A, B] =

  def put(a: A)(implicit F: Functor[F]): F[B] =

  def puts(f: I => A)(implicit F: Functor[F]): F[B] =

  def set: F[A => B] =

  def pos: I =

  def peek(a: A)(implicit F: Comonad[F]): B =

  def peeks(f: I => A)(implicit F: Comonad[F]): B =

  def seek[J](j: J): IndexedStoreT[F, J, A, B] =
    indexedStoreT((set, j))

  def seeks[J](f: I => J): IndexedStoreT[F, J, A, B] =
    indexedStoreT((set, f(pos)))

  def experiment[G[_]](f: I => G[A])(implicit F: Comonad[F], G: Functor[G]): G[B] =

  def copoint(implicit F: Comonad[F], ev: I <:< A): B =

  def map[C](f: B => C)(implicit ftr: Functor[F]): IndexedStoreT[F, I, A, C] =
    indexedStoreT(mapRunT(k => f compose k))

  def duplicate[J](implicit F: Comonad[F]): IndexedStoreT[F, I, J, IndexedStoreT[F, J, A, B]] =
    indexedStoreT((F.cobind(run._1)(ff => (a: J) => indexedStoreT((ff, a))), pos))

  def cobind[K, C](f: IndexedStoreT[F, K, A, B] => C)(implicit F: Cobind[F]): IndexedStoreT[F, I, K, C] =
    indexedStoreT((F.cobind(run._1)(ff => (a: K) => f(indexedStoreT((ff, a)))), pos))

  /** Two disjoint lenses can be paired */
  def product[J, C, D](that: IndexedStoreT[F, J, C, D])(implicit M: Bind[F]): IndexedStoreT[F, (I, J), (A, C), (B, D)] =
    IndexedStoreT(M.bind(set) { s => => { (ac: (A, C)) => (s(ac._1), t(ac._2))})}, (pos, that.pos))

  /** alias for `product` */
  def ***[J, C, D](that: IndexedStoreT[F, J, C, D])(implicit M: Bind[F]): IndexedStoreT[F, (I, J), (A, C), (B, D)] = product(that)

  private def mapRunT[C](f: (A => B) => C)(implicit F: Functor[F]): (F[C], I) =
    (, run._2)

object IndexedStoreT extends StoreTInstances with StoreTFunctions

trait IndexedStoreTFunctions {

  def indexedStoreT[F[_], I, A, B](r: (F[A => B], I)): IndexedStoreT[F, I, A, B] = IndexedStoreT(r)

  def indexedStore[I, A, B](i: I)(f: A => B): IndexedStore[I, A, B] =
    indexedStoreT[Id, I, A, B](f -> i)

trait StoreTFunctions extends IndexedStoreTFunctions {

  def storeT[F[_], A, B](r: (F[A => B], A)): StoreT[F, A, B] =
    indexedStoreT[F, A, A, B](r)

  def store[A, B](a: A)(f: A => B): Store[A, B] =
    storeT[Id, A, B](f -> a)
sealed abstract class IndexedStoreTInstances2 {
  implicit def indexedStoreTContravariant[F[_], I, B](implicit F0: Functor[F]): Contravariant[IndexedStoreT[F, I, ?, B]] =
    new IndexedStoreTContravariant[F, I, B] {
      implicit def F: Functor[F] = F0
sealed abstract class IndexedStoreTInstances1 extends IndexedStoreTInstances2 {
  implicit def indexedStoreTFunctorLeft[F[_], A, B]: Functor[IndexedStoreT[F, ?, A, B]] =
    new IndexedStoreTFunctorLeft[F, A, B] {}
sealed abstract class IndexedStoreTInstances0 extends IndexedStoreTInstances1 {
  implicit def indexedStoreTBifunctor[F[_], A](implicit F0: Functor[F]): Bifunctor[IndexedStoreT[F, ?, A, ?]] =
    new IndexedStoreTBifunctor[F, A] {
      implicit def F: Functor[F] = F0
sealed abstract class IndexedStoreTInstances extends IndexedStoreTInstances0 {
  implicit def indexedStoreTFunctorRight[F[_], I, A](implicit F0: Functor[F]): Functor[IndexedStoreT[F, I, A, ?]] =
    new IndexedStoreTFunctorRight[F, I, A] {
      implicit def F: Functor[F] = F0
sealed abstract class StoreTInstances2 extends IndexedStoreTInstances {
  implicit def storeTCobind[F[_], A](implicit F0: Cobind[F]): Cobind[StoreT[F, A, ?]] =
    new StoreTCobind[F, A] {
      implicit def F: Cobind[F] = F0
sealed abstract class StoreTInstances1 extends StoreTInstances2 {
  implicit def storeTComonad[F[_], A](implicit F0: Comonad[F]): Comonad[StoreT[F, A, ?]] =
    new StoreTComonad[F, A] {
      implicit def F: Comonad[F] = F0
sealed abstract class StoreTInstances0 extends StoreTInstances1 {
  implicit def storeTComonadStore[F[_], A](implicit F0: Comonad[F]): ComonadStore[StoreT[F, A, ?], A] =
    new StoreTComonadStore[F, A] {
      implicit def F: Comonad[F] = F0
abstract class StoreTInstances extends StoreTInstances0 {
  implicit def storeTCohoist[S]: Cohoist[λ[(ƒ[_], α) => StoreT[ƒ, S, α]]] =
    new StoreTCohoist[S] {}

private trait IndexedStoreTFunctorLeft[F[_], A0, B0] extends Functor[IndexedStoreT[F, ?, A0, B0]]{
  override def map[A, B](fa: IndexedStoreT[F, A, A0, B0])(f: A => B): IndexedStoreT[F, B, A0, B0] = fa imap f

private trait IndexedStoreTFunctorRight[F[_], I0, A0] extends Functor[IndexedStoreT[F, I0, A0, ?]]{
  implicit def F: Functor[F]
  override def map[A, B](fa: IndexedStoreT[F, I0, A0, A])(f: A => B): IndexedStoreT[F, I0, A0, B] = fa map f

private trait IndexedStoreTContravariant[F[_], I0, B0] extends Contravariant[IndexedStoreT[F, I0, ?, B0]] {
  implicit def F: Functor[F]
  override def contramap[A, B](fa: IndexedStoreT[F, I0, A, B0])(f: B => A): IndexedStoreT[F, I0, B, B0] = fa contramap f

private trait IndexedStoreTBifunctor[F[_], A0] extends Bifunctor[IndexedStoreT[F, ?, A0, ?]] {
  implicit def F: Functor[F]
  override def bimap[A, B, C, D](fab: IndexedStoreT[F, A, A0, B])(f: A => C, g: B => D): IndexedStoreT[F, C, A0, D] = (fab bimap f)(g)

private trait StoreTCobind[F[_], A0] extends Cobind[StoreT[F, A0, ?]] with IndexedStoreTFunctorRight[F, A0, A0] {
  implicit def F: Cobind[F]
  def cobind[A, B](fa: StoreT[F, A0, A])(f: (StoreT[F, A0, A]) => B) = fa cobind f

private trait StoreTComonad[F[_], A0] extends Comonad[StoreT[F, A0, ?]] with StoreTCobind[F, A0] {
  implicit def F: Comonad[F]
  override def cojoin[A](a: StoreT[F, A0, A]) = a.duplicate
  def copoint[A](p: StoreT[F, A0, A]) = p.copoint

private trait StoreTComonadStore[F[_], S] extends ComonadStore[StoreT[F, S, ?], S] with StoreTComonad[F, S] {
  def pos[A](w: StoreT[F, S, A]): S = w.pos
  def peek[A](s: S, w: StoreT[F, S, A]): A = w peek s
  override def peeks[A](s: S => S, w: StoreT[F, S, A]): A = w peeks s
  override def seek[A](s: S, w: StoreT[F, S, A]): StoreT[F, S, A] = w seek s
  override def seeks[A](s: S => S, w: StoreT[F, S, A]): StoreT[F, S, A] = w seeks s
  override def experiment[G[_], A](s: S => G[S], w: StoreT[F, S, A])(implicit FG: Functor[G]): G[A] = w experiment s

private trait StoreTCohoist[S] extends Cohoist[λ[(ƒ[_], α) => StoreT[ƒ, S, α]]] {
  def lower[G[_] : Cobind, A](a: StoreT[G, S, A]) =
    Cobind[G].map( S => A) => z(

  def cohoist[M[_], N[_]: Comonad](f: M ~> N) =
    new (StoreT[M, S, ?] ~> StoreT[N, S, ?]) {
      def apply[A](c: StoreT[M, S, A]) = {
        val (m, a) =
        StoreT((f(m), a))

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