Updated to Scala 3

Author: Undalevein

scala/anagrams.scala

@@ -1,24 +1,20 @@
-def swap(a: Array[Char], i: Int, j: Int) {
+def swap(a: Array[Char], i: Int, j: Int): Unit =
   val saved = a(i)
   a(i) = a(j)
   a(j) = saved
-}
 
-def generatePermutations(a: Array[Char], n: Int) {
-  if (n == 0) {
+def generatePermutations(a: Array[Char], n: Int): Unit =
+  if n == 0 then
     println(String.valueOf(a))
-  } else {
-    for (i <- 0 until n) {
+  else
+    for i <- 0 until n do
       generatePermutations(a, n-1)
-      swap(a, if (n % 2 == 0) 0 else i, n)
-    }
+      swap(a, if n % 2 == 0 then 0 else i, n)
     generatePermutations(a, n-1)
-  }
-}
 
-if (args.length != 1) {
-  Console.err.println("Exactly one argument is required")
-  sys.exit(1)
-}
-var word = args(0)
-generatePermutations(word.toCharArray, word.length-1)
+@main def anagrams(args: String*) =
+  if args.length != 1 then
+    Console.err.println("Exactly one argument is required")
+    sys.exit(1)
+  var word = args(0)
+  generatePermutations(word.toCharArray, word.length-1)

scala/animals.scala

@@ -1,22 +1,19 @@
-abstract class Animal(name: String) {
+trait Animal(name: String):
   def speak = s"$name says $sound"
   def sound: String
-}
 
-class Cow(name: String) extends Animal(name) {
-  override def sound() = "moooo"
-}
+class Cow(name: String) extends Animal(name):
+  def sound = "moooo"
 
-class Horse(name: String) extends Animal(name) {
-  override def sound() = "neigh"
-}
+class Horse(name: String) extends Animal(name):
+  def sound = "neigh"
 
-class Sheep(name: String) extends Animal(name) {
-  override def sound() = "baaaa"
-}
+class Sheep(name: String) extends Animal(name):
+  def sound = "baaaa"
 
-var h = new Horse("CJ")
-assert(h.speak == "CJ says neigh")
-var c = new Cow("Bessie")
-assert(c.speak == "Bessie says moooo")
-assert(new Sheep("Little Lamb").speak == "Little Lamb says baaaa")
+@main def animals() =
+  var h = new Horse("CJ")
+  assert(h.speak == "CJ says neigh")
+  var c = new Cow("Bessie")
+  assert(c.speak == "Bessie says moooo")
+  assert(new Sheep("Little Lamb").speak == "Little Lamb says baaaa")

scala/test.ps1

@@ -0,0 +1,32 @@
+function Assert-MatchTests {
+    param (
+        [Parameter(Mandatory = $true, ValueFromPipeline)] $TestResult
+    )
+
+    if ($TestResult) {
+        Write-Error "Output does not match expected results."
+    }
+}
+
+$Error.clear()
+scala "$PSScriptRoot\anagrams.scala" -- rats |
+    Compare-Object (Get-Content "$PSScriptRoot\..\test\rats_heap_expected") |
+    Assert-MatchTests &&
+scala "$PSScriptRoot\animals.scala" &&
+scala "$PSScriptRoot\clockhands.scala" |
+    Compare-Object (Get-Content "$PSScriptRoot\..\test\clockhands_expected") |
+    Assert-MatchTests &&
+scala "$PSScriptRoot\clockhandsTime.scala" |
+    Compare-Object (Get-Content "$PSScriptRoot\..\test\clockhands_expected") |
+    Assert-MatchTests &&
+scala "$PSScriptRoot\triple.scala" |
+    Compare-Object (Get-Content "$PSScriptRoot\..\test\triple_expected") |
+    Assert-MatchTests &&
+ForEach-Object 'foo'
+
+if ($Error -or !$?) {
+    "*** SCALA TESTS FAILED ***"
+}
+else {
+    "SCALA TESTS PASSED"
+}