My Swift Snipets ref: http://qiita.com/asus4/items/15f843c39929aedd3013

date_sample.swift

let date = NSDate()
let dateFormatter = NSDateFormatter()
dateFormatter.setDateFormat("yyyy-MM-dd-HH-mm-ss")
let dateStr = dateFormatter.stringFromDate(date)

delegate_sample.h

typedef void (^JsonDelegate)(NSDictionary json);

delegate_sample.swift

class TheDelegteSample {
    // 定義
    typealias JsonDelegate = (json:NSDictionary) -> ()

    // 変数
    var jsonDelegate:JsonDelegate?

    // 叩く
    func foo() {
        if jsonDelegate {
            jsonDelegate(json:theJson)
        }
    }
}

file_sample.swift

// デスクトップから取得。構造体になってるので注意
let directory = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DesktopDirectory, NSSearchPathDomainMask.UserDomainMask, true)
let directoryStr = directory[0] as NSString
let path = NSString(format: "%@/%@.txt", directoryStr, "thefile")        
let url = NSURL(fileURLWithPath:path)

gcd_sample.swift

// dispatch_get_main_queueは廃止
// 5秒後に
let offset = 5.0
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(offset * Double(NSEC_PER_SEC))),dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),{
    // TODO dispatch
})

// Background Task
let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, {
  // Background
})

SoundManager.swift

import Cocoa

class SoundManager {

    struct Cache {
        static let sound = Dictionary<String, NSSound>()
    }


    init() {
    }

    class func getSound(name:String) -> NSSound {
        var sound = Cache.sound[name]

        if sound == nil  {
            let soundpath = NSBundle.mainBundle().pathForResource(name, ofType:"aif")
            sound = NSSound(contentsOfFile: soundpath, byReference: false)
        }

        return sound!
    }

    class func play(name:String) {
        let sound = SoundManager.getSound(name)
        sound.play()
    }
}