Scala学习笔记（七）：Rational、隐式转换、偏函数、闭包、重复参数及柯里化

class Rational(n: Int, d: Int) {

  require(d != 0)

  private val g: Int = gcd(n, d)

  val number: Int = n / g

  val denom: Int = d / g

  def this(n: Int) = this(n, 1)

  override def toString: String =

    if (denom != 1) number + "/" + denom else number.toString

  def add(that: Rational): Rational = {

    new Rational(number * that.denom + denom * that.number, denom * that.denom)

  }

  def +(x: Int): Rational = {

    add(new Rational(x))

  }

  def +(that: Rational): Rational = add(that)

  private def gcd(a: Int, b: Int): Int = {

    if (b == 0) a else gcd(b, a % b)

  }

}

object Rational extends App {

  val rational1: Rational = new Rational(1, 2)

  val rational2: Rational = new Rational(1, 2)

  val add: Rational = rational1 + rational2

  println(s"add=======>$add")

  //隐式转换

  implicit def intToRational(x: Int): Rational = new Rational(x)

  println("Int*Iational===>" + 2 + intToRational(2))

  //偏函数

  val sum = (x: Int, y: Int, z: Int) => x + y + z

  val b = sum(1, _: Int, 3)

  println(b(1))

  //闭包

  val more = 1

  val offset = (x: Int) => x + more

  //重复参数

  def echo(s: String*): Unit = s.foreach(println)

  echo("a", "b")

  //柯里化

  def curriedSum(x: Int)(y: Int) = x + y

  val add1 = (x: Int) => curriedSum(1) _

  println(add1)

}

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Scala学习笔记（七）：Rational、隐式转换、偏函数、闭包、重复参数及柯里化

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