Scala example source code file (map.scala)

This example Scala source code file (map.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.

Learn more about this Scala project at its project page.

Java - Scala tags/keywords

applicative, bitraverse, entry, mapinstances, simpleimmutableentry

The map.scala Scala example source code

package scalaz
package std.java.util

trait MapInstances {

  import java.util.Map.Entry
  import java.util.AbstractMap.SimpleImmutableEntry

  implicit val mapEntryBitraverse: Bitraverse[Entry] = new Bitraverse[Entry] {
    override def bimap[A, B, C, D](fab: Entry[A, B])(f: A => C, g: B => D) =
      new SimpleImmutableEntry(f(fab.getKey), g(fab.getValue))

    def bitraverseImpl[G[_]: Applicative, A, B, C, D](fab: Entry[A, B])
                                                 (f: A => G[C], g: B => G[D]) =
      Applicative[G].apply2(f(fab.getKey), g(fab.getValue))(new SimpleImmutableEntry(_, _))

  }
}

object map extends MapInstances