Konstantin Läufer klaeufer

Advanced Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

	object KLSigPipeFun {
	def main(args: Array[String]) = {
	val lines = scala.io.Source.stdin.getLines()
	val lineNumbers = Iterator.from(1)
	val numberedLines = lineNumbers.zip(lines)
	val okLines = numberedLines takeWhile { _ => !scala.sys.process.stdout.checkError() }
	val outLines = okLines map { case (number, line) => println(number + ":" + line) }
	println(outLines.length + " lines counted")
	}
	}