SCALA-5: scala generics sample code

scala-core-oop/src/main/scala/com/baeldung/scala/generics/GenericsIntro.scala

@@ -0,0 +1,74 @@
+package com.baeldung.scala.generics
+
+object GenericsIntro {
+
+  case class Apple(name: String)
+
+  def main(args: Array[String]): Unit = {
+    NonGenericWay.run()
+  }
+
+  object LongHandWay {
+
+    case class AppleMagicHat(magic: Apple)
+
+    case class RabbitMagicHat(magic: Rabbit)
+
+    def run(): Unit = {
+      val someHat = AppleMagicHat(Apple("gala"))
+      val apple: Apple = someHat.magic
+      println(apple.name)
+    }
+  }
+
+  object NonGenericWay {
+
+    case class MagicHat(magic: AnyRef)
+
+    def run(): Unit = {
+      val someHat = MagicHat(Rabbit(2))
+      val apple: Apple = someHat.magic.asInstanceOf[Apple]
+      println(apple.name)
+    }
+  }
+
+  object GenericWay {
+
+    case class MagicHat[A](magic: A)
+
+    def run(): Unit = {
+      val rabbitHat = MagicHat[Rabbit](Rabbit(2))
+      val rabbit: Rabbit = rabbitHat.magic
+      println(rabbit.cuteness)
+    }
+  }
+
+  case class Rabbit(cuteness: Int)
+
+  object GenericMethods {
+    def middle[A](input: Seq[A]): A = input(input.size / 2)
+
+    def itemsAt[A, B](index: Int, seq1: Seq[A], seq2: Seq[B]): (A, B) = (seq1(index), seq2(index))
+
+    def run() = {
+
+      val rabbits = List[Rabbit](Rabbit(2), Rabbit(3), Rabbit(7))
+      val middleRabbit: Rabbit = middle[Rabbit](rabbits)
+
+      val apples = List[Apple](Apple("gala"), Apple("pink lady"))
+      val items: (Rabbit, Apple) = itemsAt[Rabbit, Apple](1, rabbits, apples)
+    }
+
+  }
+
+  object NonGenericMethods {
+    def totalSize(list1: List[_], list2: List[_]): Int = list1.length + list2.length
+    def run() = {
+      val rabbits = List[Rabbit](Rabbit(2), Rabbit(3), Rabbit(7))
+      val strings = List("a", "b")
+      val size: Int = totalSize(rabbits, strings)
+    }
+
+  }
+
+}