Scala example source code file (Foldable1Test.scala)

This example Scala source code file (Foldable1Test.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

double, foldable1test, ilist, int, nonemptylist, oneand, speclite, string

The Foldable1Test.scala Scala example source code

package scalaz

import std.AllInstances._
import syntax.foldable1._
import scalaz.scalacheck.ScalazArbitrary._
import org.scalacheck.Prop.forAll

object Foldable1Test extends SpecLite {
  "maximum1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      (xs.maximum1) must_===(xs.list.toList.max)
  }
  "maximumOf1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      val f: Int => Double = 1D + _
      (xs maximumOf1 f) must_===((xs.list.toList.iterator map f).max)
  }
  "maximumBy1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      val f: Int => String = _.toString
      (xs maximumBy1 f) must_===((xs.list zip (xs.list map f)).toList.maxBy(_._2)._1)
  }
  "minimum1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      (xs.minimum1) must_===(xs.list.toList.min)
  }
  "minimumOf1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      val f: Int => Double = 1D + _
      (xs minimumOf1 f) must_===((xs.list.toList.iterator map f).min)
  }
  "minimumBy1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      val f: Int => String = _.toString
      (xs minimumBy1 f) must_===((xs.list zip (xs.list map f)).toList.minBy(_._2)._1)
  }

  "distinct1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      xs.distinct1.toList must_== xs.toList.distinct
      xs.distinct1(Order.order((_,_) => Ordering.EQ)).length must_== 1
  }

  "distinctE1" ! forAll {
    (xs: NonEmptyList[Int]) =>
      xs.distinctE1.toList must_== xs.toList.distinct
      xs.distinctE1(Equal.equal((_,_) => true)).length must_== 1
  }

  private val L = Foldable1[NonEmptyList]

  "product foldRight1 equivalence" ! forAll {
    (l: NonEmptyList[IList[Int]], l2: NonEmptyList[IList[Int]]) =>
      (L.product(L).foldRight1((l, l2))(_ ++ _)
       must_===((l.list ++ l2.list).flatten))
  }

  "product foldLeft1 equivalence" ! forAll {
    (l: NonEmptyList[IList[Int]], l2: NonEmptyList[IList[Int]]) =>
      (L.product(L).foldLeft1((l, l2))((xs, x) => x ++ xs)
       must_===((l.list ++ l2.list).reverse.flatten))
  }

  "intercalate1" ! forAll {
    (l: NonEmptyList[IList[Int]], x: IList[Int]) =>
      l.intercalate1(x) must_=== Foldable[IList].intercalate(l.list, x)
  }

  "toNel" ! forAll {
    intAnd: OneAnd[IList, Int] =>
    intAnd.toNel must_=== NonEmptyList.nel(intAnd.head, intAnd.tail)
  }
}