SwiftでPPAPやってみた

PPAPTalker.swift

//: Playground - PPAP: http://qiita.com/KIchiro/items/74d117ff894ac10b72e0 のSwift版

import UIKit
import Foundation
import AVFoundation
import XCPlayground

XCPlaygroundPage.currentPage.needsIndefiniteExecution = true

// enumの一覧を使いたい
// http://qiita.com/su_k/items/c1c6a91324cf12151256
public protocol EnumEnumerable {
    associatedtype Case = Self
}

public extension EnumEnumerable where Case: Hashable {
    private static var iterator: AnyIterator<Case> {
        var n = 0
        return AnyIterator {
            defer { n += 1 }
            let next = withUnsafePointer(to: &n) {
                UnsafeRawPointer($0).assumingMemoryBound(to: Case.self).pointee
            }
            return next.hashValue == n ? next : nil
        }
    }
    
    public static func enumerate() -> EnumeratedSequence<AnySequence<Case>> {
        return AnySequence(self.iterator).enumerated()
    }
    
    public static var cases: [Case] {
        return Array(self.iterator)
    }

    public static var count: Int {
        return self.cases.count
    }
}

// 列挙体
// http://qiita.com/hachinobu/items/392c96820588d1c03b0c

fileprivate enum Word: String, EnumEnumerable {
    case pen
    case pineapple
    case apple
}

fileprivate enum PpapState {
    case initial, p, pp, ppa, ppap
    
    func transition(_ next: Word) -> PpapState {
        switch (next, self) {
        case (.pen, .initial): return .p
        case (.pineapple, .p): return .pp
        case (.apple, .pp): return .ppa
        case (.pen, .ppa): return .ppap
        default: return .initial
        }
    }
}

// 喋らせる
// http://qiita.com/takecian/items/096b07e2d0437454f670

let talker = AVSpeechSynthesizer()

func ppapMachine() {
    var state: PpapState = .initial
    while state != .ppap {
        let word = Word.cases[Int(arc4random_uniform(UInt32(Word.count)))]
        state = state.transition(word)
        speakWord(generateSentence(word))
        RunLoop.main.run(until: Date(timeIntervalSinceNow: 1))
        talker.stopSpeaking(at: .word)
    }
    speakWord("Apple pen")
    RunLoop.main.run(until: Date(timeIntervalSinceNow: 2))
    talker.stopSpeaking(at: .word)
    speakWord("Pineapple pen")
    RunLoop.main.run(until: Date(timeIntervalSinceNow: 3.5))
    talker.stopSpeaking(at: .word)
    speakWord("Uh!")
    RunLoop.main.run(until: Date(timeIntervalSinceNow: 1))
    talker.stopSpeaking(at: .word)
    speakWord("Pen pineapple apple pen!")
}

fileprivate func generateSentence(_ word: Word) -> String {
    switch word {
    case .apple:
        return "I have an \(word.rawValue)"
    default:
        return "I have a \(word.rawValue)"
    }
}

func speakWord(_ string: String) {
    let utterance = AVSpeechUtterance(string: string)
    utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
    talker.speak(utterance)
}

ppapMachine()