Scala - Core Scala - First-Class Functions(library function, util.Rnadom.nextInt)

Learning Scala:
Practical Functional Programming for the JVM
(O'Reilly Media)
Jason Swartz (著)

開発環境

• OS X Yosemite - Apple (OS)
• Emacs (Text Editor)
• Scala (プログラミング言語)

Learning Scala: Practical Functional Programming for the JVM (Jason Swartz (著)、O'Reilly Media)のPart Ⅰ. (Core Scala)、Chapter 5.(First-Class Functions)、Exercises 2.(No. 1874)を解いてみる。

その他参考書籍

• Programming Scala: Scalability = Functional Programming + Objects

Exercises 2.(No. 1874)

コード(Emacs)

import util.Random.nextInt

val max = (a:Int, b:Int) => {
  if (a > b) a
  else b
}
val min = (a:Int, b:Int) => {
  if (a > b) b else a
}

val apply = (f:(Int, Int) => Int, a:Int, b:Int) => f(a, b)

val (x, y) = (nextInt, nextInt)

println(s"$x, $y")
println(s"max: ${max(x, y)}")
println(apply(max, x, y))
println(s"min: ${min(x, y)}")
println(apply(min, x, y))
println(s"second: ${apply((a:Int, b:Int) => b, x, y)}")

入出力結果(Terminal, REPL(Read, Eval, Print, Loop))

$ scala-2.11 sample2.scala
-945818191, -2060746920
max: -945818191
-945818191
min: -2060746920
-2060746920
second: -2060746920
$