Deferredの実装をswiftで書いてみた Playgroundに貼付けて動く

gistfile1.swift

import Cocoa


// http://qiita.com/saiten/items/c2ac4df40ad001179afa
// https://github.com/saiten/STDeferred/blob/master/STDeferred/STDeferred.m
// を参考にした。

class PAMDeferred{
    class func deferred()->PAMDeferred{
        return PAMDeferred()
    }

    enum DeferredState:Int{ case Unresolved,Resolved,Rejected}
    var _state:DeferredState = .Unresolved
    
    func isResolved()->Bool{
        return _state == .Resolved
    }
    
    func isRejected()->Bool{
        return _state == .Rejected
    }
    
    func resolve(resultObject:AnyObject){
        if( _state == .Unresolved ){
            _state = .Resolved
            _fire(resultObject)
        }
    }
    func reject(resultObject:AnyObject){
        if( _state == .Unresolved ){
            _state = .Rejected
            _fire(resultObject)
        }
    }
    
    var _doneList:Array<(AnyObject)->Void> = []
    var _failList:Array<(AnyObject)->Void> = []
    var _alwaysList:Array<(AnyObject)->Void> = []

    var _resultObject:AnyObject?=nil
    
    func _fire(resultObject:AnyObject){
        _resultObject = resultObject
        let list:Array = isResolved() ? _doneList : _failList
        for block:(AnyObject)->Void in list + _alwaysList{
            block(resultObject)
        }
    }
    
    func then(block:(AnyObject)->Void)->PAMDeferred{
        _doneList.append(block)
        if( _state == .Resolved ){
            block(_resultObject!)
        }
        return self
    }
    func fail(block:(AnyObject)->Void)->PAMDeferred{
        _failList.append(block)
        if( _state == .Rejected ){
            block(_resultObject!)
        }
        return self
    }
}

 // 処理終わった後に、thenやfailを登録しても動く
let def1 = PAMDeferred()
def1.resolve("resolve")
def1.then({ obj in println("success \(obj)") })
    .then({ obj in println("success2 \(obj)") })
    .fail({ obj in println("failed \(obj)")  })
    .fail({ obj in println("failed2 \(obj)")  })


// thenやfailを登録した後に処理が終わっても動く
PAMDeferred.deferred()
    .then({ obj in println("success \(obj)") })
    .then({ obj in println("success2 \(obj)") })
    .fail({ obj in println("failed \(obj)")  })
    .fail({ obj in println("failed2 \(obj)")  })
    .resolve("resolve")
PAMDeferred.deferred()
    .then({ obj in println("success \(obj)") })
    .then({ obj in println("success2 \(obj)") })
    .fail({ obj in println("failed \(obj)")  })
    .fail({ obj in println("failed2 \(obj)")  })
    .reject("reject")