Scala example source code file (TreeTest.scala)

This example Scala source code file (TreeTest.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

ascii, node, seq, speclite, stream, traverse, tree, treetest

The TreeTest.scala Scala example source code

package scalaz

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

object TreeTest extends SpecLite {

  checkAll("Tree", order.laws[Tree[Int]])
  checkAll("Tree", traverse1.laws[Tree])
  checkAll("Tree", applicative.laws[Tree])
  checkAll("Tree", comonad.laws[Tree])
  checkAll("Tree", align.laws[Tree])
  checkAll("Tree", zip.laws[Tree])

  checkAll(FoldableTests.anyAndAllLazy[Tree])

  "indexed" ! forAll { xs: Tree[Byte] =>
    val F = Traverse[Tree]
    val a = F.indexed(xs)
    Equal[Tree[Byte]].equal(a.map(_._2), xs) must_=== true
    F.toList(a) must_=== F.toList(xs).zipWithIndex.map{case (a, b) => (b, a)}
  }

  "infinite Tree flatten" ! {
    Node(0, Stream.from(1).map(Leaf(_))).flatten
    true
  }

  "A tree must can be rendered as an ASCII string" ! {
      Node(1, Stream(Node(2, Stream(Leaf(3))), Leaf(4))).drawTree must_== Seq(
      "1",
      "|",
      "+- 2",
      "|  |",
      "|  `- 3",
      "|",
      "`- 4").mkString("", "\n", "\n")
  }
}