Swift Promise example

gistfile1.txt

// Example of a promise that could be used to wrap bracketed capture

import Foundation
import BrightFutures

func grabBrackets (n:Int) -> Future<[AnyObject]> {
    let promise = Promise<[AnyObject]>()
    
    var data = [AnyObject]()
    
    let allDoneCheck = { () -> Void in
        if data.count == n {
            promise.success(data)
        }
    }
    
    // simulate return of N items
    Queue.global.async {
        //NSThread.sleepForTimeInterval(1.0)
        data.append(1)
        allDoneCheck()

        Queue.global.async {
            //NSThread.sleepForTimeInterval(1.0)
            data.append(2)
            allDoneCheck()
        }

    }


    return promise.future
}

// goes unfulfilled
let f3 = grabBrackets(3)
f3.value

// gets fulfilled
let f2 = grabBrackets(2)
f2.value