monocle.function.Each.scala Maven / Gradle / Ivy

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package monocle.function

import monocle.{PTraversal, Traversal}
import scala.annotation.implicitNotFound
import scalaz.Traverse

@implicitNotFound("Could not find an instance of Each[${S},${A}], please check Monocle instance location policy to " +
  "find out which import is necessary")
trait Each[S, A] {

  /**
   * Creates a Traversal from a monomorphic container S to all of its elements of type A
   */
  def each: Traversal[S, A]

}

object Each extends EachFunctions


trait EachFunctions {

  def each[S, A](implicit ev: Each[S, A]): Traversal[S, A] = ev.each

  def traverseEach[S[_]: Traverse, A]: Each[S[A], A] = new Each[S[A], A] {
    def each = PTraversal.fromTraverse[S, A, A]
  }

}