Scala example source code file (ConstTest.scala)

This example Scala source code file (ConstTest.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, const, consttest, equal, function0, functor, list, monoid, order, semigroup, speclite, string, traverse

The ConstTest.scala Scala example source code

package scalaz

import std.AllInstances._
import scalaz.scalacheck.ScalazProperties._
import scalaz.scalacheck.ScalazArbitrary._
import Const._
import org.scalacheck.Prop.forAll

object ConstTest extends SpecLite {
  checkAll("Const", order.laws[Const[Int, String]])

  checkAll("Const List"  , applicative.laws[λ[α => Const[List[Int], α]]])
  checkAll("Const Option", applicative.laws[λ[α => Const[Option[Int], α]]])

  checkAll(traverse.laws[Const[Int, ?]])
  checkAll(contravariant.laws[Const[Int, ?]])

  "const functions" in {
    "const" ! forAll { (x: Int, y: Function0[String]) =>
      const(x)(y) == x
    }
  }

  object instances {
    def functor[C] = Functor[Const[C, ?]]
    def traverse[C] = Traverse[Const[C, ?]]
    def functorMax[C: Monoid] = Functor[Const[C, ?]]
    def apply[C: Semigroup] = Apply[Const[C, ?]]
    def applicative[C: Monoid] = Applicative[Const[C, ?]]
    def equal[C: Equal, A] = Equal[Const[C, A]]
    def equalMax[C: Order, A] = Equal[Const[C, A]]
    def order[C: Order, A] = Order[Const[C, A]]
  }
}