第18章：Scalaのパターンマッチ ref: http://qiita.com/f81@github/items/aa46c248a38a171ed955

file1.txt

$ scalac PatternMatchConst.scala

$ scala PatternMatchConst
random:true
number:1

file11.txt

$ scalac PatternMatchSeq.scala

$ scala PatternMatchSeq
number:2

file13.txt

$ scalac PatternMatchTuple.scala

$ scala PatternMatchTuple
result:OK

file15.txt

$ scalac PatternMatchConstructor.scala

$ scala PatternMatchConstructor
所属:一号生

file3.txt

$ scalac PatternMatchType.scala

$ scala PatternMatchType
num=1
bool=true
name=J

file5.txt

$ scalac PatternMatchWild.scala

$ scala PatternMatchWild
number:4

file7.txt

$ scalac PatternMatchNoWild.scala

$ scala PatternMatchNoWild
num=1
bool=true
scala.MatchError: J (of class java.lang.String)
    at PatternMatch3_2$$anonfun$main$1.apply(PatternMatch3_2.scala:7)
    at PatternMatch3_2$$anonfun$main$1.apply(PatternMatch3_2.scala:6)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at PatternMatch3_2$.main(PatternMatch3_2.scala:6)
    at PatternMatch3_2.main(PatternMatch3_2.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at scala.tools.nsc.util.ScalaClassLoader$$anonfun$run$1.apply(ScalaClassLoader.scala:71)
    at scala.tools.nsc.util.ScalaClassLoader$class.asContext(ScalaClassLoader.scala:31)
    at scala.tools.nsc.util.ScalaClassLoader$URLClassLoader.asContext(ScalaClassLoader.scala:139)
    at scala.tools.nsc.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:71)
    at scala.tools.nsc.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:139)
    at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:28)
    at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:45)
    at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:35)
    at scala.tools.nsc.ObjectRunner$.runAndCatch(ObjectRunner.scala:45)
    at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:74)
    at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:96)
    at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:105)
    at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

file9.txt

$ scalac PatternMatchVar.scala

$ scala PatternMatchVar
random:4
number:8

PatternMatchConst.scala

import scala.util.Random

object PatternMatchConst {

  def main(args: Array[String]): Unit = {
    val random = Random.nextBoolean

    val num = random match {
      case true => 1
      case false => 0
    }

    println("random:" + random)
    println("number:" + num)
  }

}

PatternMatchConstructor.scala

object PatternMatchConstructor {

  case class Person(name: String, age: Int, education: String)

  def main(args: Array[String]): Unit = {
    val person = Person("椿山 清美", 15, "男塾")

    val belongTo = person match {
      case Person("独眼鉄", _, "男塾") => "鎮守直廊三人衆 "
      case Person("椿山 清美", _, "男塾") => "一号生"
      case _ => "一般市民"
    }

    println("所属:" + belongTo)
  }

}

PatternMatchNoWild.scala

object PatternMatchNoWild {

  def main(args: Array[String]): Unit = {
    val list = List(1, true, "J")

    for (value <- list) {
      value match {
        case num: Integer => println("num=" + num)
        case bool: Boolean => println("bool=" + bool)
      }
    }

  }

}

PatternMatchSeq.scala

object PatternMatchSeq {

  def main(args: Array[String]): Unit = {
    val seq = Seq(1, 2, 3, 4)

    val result = seq match {
      case Seq(1, a, _*) => a
      case _ => 0
    }

    println("number:" + result)
  }

}

PatternMatchTuple.scala

object PatternMatchTuple {

  def main(args: Array[String]): Unit = {
    val tuple = (1, 2, "OK")

    val result = tuple match {
      case (1, 2, x) => x
      case _ => "NG"
    }

    println("result:" + result)
  }

}

PatternMatchType.scala

object PatternMatchType {

  def main(args: Array[String]): Unit = {
    val list = List(1, true, "J")

    for (value <- list) {
      value match {
        case num: Integer => println("num=" + num)
        case bool: Boolean => println("bool=" + bool)
        case name: String => println("name=" + name)
        case _ => println("value=" + value)
      }
    }

  }

}

PatternMatchVar.scala

object PatternMatchVar {

  def main(args: Array[String]): Unit = {
    val random = 4

    val result = random match {
      case num => num * 2
    }

    println("random:" + random)
    println("number:" + result)
  }

}

PatternMatchWild.scala

object PatternMatchWild {

  def main(args: Array[String]): Unit = {
    val num = 4

    num match {
      case _ => println("number:" + num)

    }
  }

}