パターンマッチの例 #swift2 #CodePiece #swift #swiftlang

CodePiece.swift

enum Gender {
    case Male, Female
}

enum TimeSaleResult {
    case Normal, Morning, Evening
}

func TimeSale(hour:Int) -> TimeSaleResult {
    switch hour {
    case let h where h < 10:
        return .Morning
    case let h where 20 < h:
        return .Evening
    default:
        return .Normal
    }
}

let gender = Gender.Female
let age    = 30
let hour   = 12

switch (gender, age, hour) {
case (.Female, _      , _   ):                          print("女性割引")
case (_      , let age, _   ) where age < 20:           print("学生")
case (_      , let age, _   ) where 60 < age:           print("シニア")
case (_      , _      , hour) where          hour < 10: print("早朝割引")
case (_      , _      , hour) where          19 < hour: print("深夜割引")
default:                                                print("通常割引")
}