Closures

[kengorab]

Functions are first-class citizens, and should be assignable to bindings inline. These functions, which can be thought of as lambdas, can have bodies which "close over" variables.

Syntax

func getCounter() {
  var count = 0
  val inc = () => count = count + 1
  val printCount = () => println("Count: " + count)

  { 
    inc: inc, 
    printCount: printCount
  }
}

val counter = getCounter()
counter.printCount()  // Prints "Count: 0"
counter.inc()
counter.printCount() // Prints "Count: 1"

[kengorab]

While the syntax for lambdas has not yet been implemented, the functionality for closures to close over locals has been successfully implemented over the course of #83, #85, #86, #87, #88, and #95.