Meet AsyncSequence

AsyncSequenceってなに？

Mobile Act ONLINE #5 で AsyncSequence の話をしました #MobileAct - usami-kの日記
https://usami-k.hatenablog.com/entry/2021/07/01/083448

Mobile Act ONLINE #5 〜 WWDC21 を振り返る 〜 - connpass
https://mobileact.connpass.com/event/216108/

1. "TZOD4FRVFODF ͬͯͳʹʁ Ӊࠤݟ
   ެี  1/16
2. Ӊࠤݟ
   ެีʢ!VTBNJLʣ w 鳍鲟鳫鳢鳣גࣜձࣾ
   J04
   鲠鳫鲰鳃鲚
   
   鲾鲻鲧鳢鱅鳁 w ٕज़ಉਓࢽ w $PNCJOF鲗鱴鱝鲆鲍鱋 w $PNCJOF鱭6*,JU鱰鲍鲐J04鲚鳏鳢։ൃ w هࣄࣥච༧ఆ w J04%$
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   $PNCJOF
   0QFSBUPS
   鲤鲜鳁 2/16
3. 4XJGU
   $PODVSSFODZ w ඇಉظॲཧ鱑࣮૷鱜鲉鱞鱔鱯鲐ʢJ04
   
   Ҏ߱ʣ w async
   
   await w 4USVDUVSFE
   $PODVSSFODZ w "DUPS w ࠓճ鱴
   async
   
   await
   鱳࿩ 3/16
4. BTZOD
   
   BXBJU
   Λ࢖Θͳ͍৔߹ func fetchThumbnail(completion: (UIImage?, Error?) -> Void) { let task = URLSession.shared.dataTask(with: request) { ... if let error = error { completion(nil, error) } else { // ... data / response ͷॲཧ ... completion(thumbnail, nil) } } task.resume() } 4/16
5. BTZOD
   
   BXBJU
   Λ࢖͏৔߹ func fetchThumbnail() async throws -> UIImage { let (data, response) = try await URLSession.shared.data(for: request) // ... data / response ͷॲཧ ... return thumbnail } w await
   鱳Օॴ鱬鲭鲱鳒鳫鳁ɺॲཧ鱑ऴ鲔鱨鱤鲎෮ؼ 5/16
6. 63-4FTTJPO
   ͷϝιου // async / await ඇରԠ൛ func dataTask(with request: URLRequest, completionHandler: (Data?, URLResponse?, Error?) -> Void) -> URLSessionDataTask // async / await ରԠ൛ func data(for request: URLRequest) async throws -> (Data, URLResponse) 6/16
7. "TZOD4FRVFODF
   ͱ͸ w Sequence
   鱳
   async
   
   await
   ରԠ൛ w 鱮鱋鱉鱋鱘鱭ʁ w 鲃鱟
   Sequence
   鱳鱏鱚鲎鱉 7/16
8. 4FRVFODF w Sequence
   鳏鳥鳀鲫鳣鱰४ڌ鱜鱤ܕ鱬鱴ɾɾɾ w for-in
   ߏจ鱑࢖鱍鲐 w ஋鱴ಉظత鱰౉鱚鲑鲐 for quake in quakes { // ... quake ͷॲཧ ... } 8/16
9. "TZOD4FRVFODF w AsyncSequence
   鳏鳥鳀鲫鳣鱰४ڌ鱜鱤ܕ鱬鱴ɾɾɾ w for-await-in
   ߏจ鱑࢖鱍鲐 w ஋鱴ඇಉظత鱰౉鱚鲑鲐 for await quake in quakes { // ... quake ͷॲཧ ... } 9/16
10. 4FRVFODF
    ΛΠςϨʔλͰݟΔ for quake in quakes { // ... quake ͷॲཧ ... } var iterator = quakes.makeIterator() while let quake = iterator.next() { // ... quake ͷॲཧ ... } 10/16
11. "TZOD4FRVFODF
    ΛΠςϨʔλͰݟΔ for await quake in quakes { // ... quake ͷॲཧ ... } var iterator = quakes.makeAsyncIterator() while let quake = await iterator.next() { // ... quake ͷॲཧ ... } 11/16
12. "TZOD4FRVFODF
    ΦϖϨʔλ let strings = quakes.map { (quake) -> String in // ... quake Λ String ʹม׵ ... } for await string in strings { // ... string ͷॲཧ ... } 12/16
13. "TZOD4FRVFODF
    ͷฒྻॲཧ let task1 = async { for await quake in quakes { // ... quake ͷॲཧ ... } } let task2 = async { for await string in strings { // ... string ͷॲཧ ... } } // task1.cancel() 13/16
14. $PNCJOF
    ͱͷൺֱ w AsyncSequence
    鱴
    $PNCJOF
    鱭ѻ鱋໰୊ྖҬ鱑ࣅ鱫鱉鲐 w AsyncSequence w J04
    
    Ҏ߱ɺݴޠ૊鲄ࠐ鲄ߏจɺ鲯鳫鳏鳣鱬෼鱐鲏鲉鱞鱉 w $PNCJOF w J04
    
    Ҏ߱ɺ鲢鳒鳤鱅鲷鱑๛෋ɺෳ਺鲱鳀鳢鱅鳘鱳鳖鱅鲰 14/16
15. ࠓޙ͸Ͳ͏ͳΔʁ w ڞଘʁ w $
    鱬鱴
    async
    
    await
    鱭
    3Y
    鱑ࠞࡏ鱜鱫࢖鲔鲑鱫鱉鲐 w ༥߹ʁ w ࢓༷ࡦఆத鱳
    AsyncStream
    鱑鱏ޓ鱉鲗༥߹鱞鲐鱐鲇ʁ w ݱ࣌఺鱬鱴鱮鱦鲎鱭鲇鱉鱍鱯鱉 15/16
16. ࢀߟ৘ใ w 88%$
    鲳鲻鲯鳟鳫
    
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    "TZOD4FRVFODF w "1*
    鳢鳍鲙鳤鳫鲱
    
    AsyncSequence
    鳏鳥鳀鲫鳣 16/16