Scala 3

Links

• new features of Scala 3

Scala 2

For comprehension

In Scala, for comprehension is a syntax sugar of a sequence of following methods

• foreach
  • e.g.

    for { item <- items } println(item)
    

• map
  • e.g.

    for { item <- items } yield item * 2
    

• flatMap
  • e.g.

    for {
    item1 <- items
    item2 <- otherItems
    } println(item)
    

• withFilter
  • e.g.

    for {
    item <- items
    if item == 0
    } println(item)
    

• For comprehensions

Specify interface implemented by lambda explicitly

// differentiate it from Supplier[Boolean]
{ () => true }: java.util.function.BooleanSupplier