Map, filter and foldLeft using an Emoji example in Scala

README.md

Original idea can be found here.

EmojiMeal.scala

object EmojiMeal extends App {
    type Ingredient = String
    type Meal = String
    type Person = String
    type Poop = String

    def cook(item: Ingredient): Meal = item match {
      case "🐮" => "🍔"
      case "🍠" => "🍟"
      case "🐔" => "🍗"
      case "🌽" => "🍿"
      case _ => "🍲"
    }

    def isVegetarian(meal: Meal): Boolean = meal match {
      case "🍟" => true
      case "🍿" => true
      case _ => false
    }

    def eat(person: Person, meal: Meal): Poop = "💩"

    val ingredients = List("🐮", "🍠", "🐔", "🌽")
    println(s"Ingredients: ${ingredients.mkString(",")}")

    val meals = ingredients.map(cook)
    println(s"Meals: ${meals.mkString(",")}")

    val vegetarianMeals = meals.filter(isVegetarian)
    println(s"Vegetarian meals: ${vegetarianMeals.mkString(",")}")

    val eaten = vegetarianMeals.foldLeft("😎")(eat)
    println(s"Eaten: ${eaten}")
}