where-where.swift

import Cocoa

// for-in
func checkForIn(array: [Int], dict: [Int: String]) {
    for num in array where dict[num] != nil {
        num
    }
}

checkForIn([1,2,3,4], dict: [1:"one", 2:"two"])

// do-catch

enum MyError: ErrorType {
    case Oooggh(String)
}

func errorProne() throws {
    throw MyError.Oooggh("nope")
}

do {
    try errorProne()
} catch MyError.Oooggh(let argument) where argument == "agree" {
    print("oooggh")
} catch MyError.Oooggh(let argument) where argument == "nope" {
    print("oooggh")
}


// while

func checkWhile(inout array: [Int]?) {
    while let arr = array where arr.count < 5 {
        array?.append(0)
    }
}

var mutableArray:[Int]? = []
checkWhile(&mutableArray)

// if

func checkIf(string: String?) {
    if let str = string where str == "checkmate" {
        print("game over")
        return
    }
    print("let's play")
}

checkIf("checkmate")

// guard

func checkGuard(string: String?) {
    guard let str = string where str != "checkmate" else {
        print("game over")
        return
    }
    print("let's play")
}

checkGuard("checkmate")

// switch-case

var value = (1,2)
switch value {
    case let (x, y) where x == 1:
        // match 1
    break
    case let (x, y) where x / 5 == 1:
        // not-match
    break

    default:
    break
}

// generics

func genericFunction<S where S: StringLiteralConvertible>(string: S) {
    print(string)
}

genericFunction("lambada")