Use helper functions for Result

APIKit/APIKit.swift

@@ -94,27 +94,25 @@ public class API {
                     dispatch_async(mainQueue, { handler(.Failure(Box(error))) })
                     return
                 }
-
-                switch self.responseBodyParser().parseData(data) {
-                case .Failure(let box):
-                    dispatch_async(mainQueue, { handler(.Failure(Box(box.unbox))) })
-
-                case .Success(let box):
-                    if let response = request.responseFromObject(box.unbox) {
-                        dispatch_async(mainQueue, { handler(.Success(Box(response))) })
+
+                let mappedResponse: Result<T.Response, NSError> = self.responseBodyParser().parseData(data).flatMap { rawResponse in
+                    if let response = request.responseFromObject(rawResponse) {
+                        return success(response)
                     } else {
                         let userInfo = [NSLocalizedDescriptionKey: "failed to create model object from raw object."]
                         let error = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
-                        dispatch_async(mainQueue, { handler(.Failure(Box(error))) })
+                        return failure(error)
                     }
+
                 }
+                dispatch_async(mainQueue, { handler(mappedResponse) })
             }
 
             task.resume()            
         } else {
             let userInfo = [NSLocalizedDescriptionKey: "failed to build request."]
             let error = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
-            dispatch_async(mainQueue, { handler(.Failure(Box(error))) })
+            dispatch_async(mainQueue, { handler(failure(error)) })
         }
     }
 }

APIKit/RequestBodyBuilder.swift

@@ -32,23 +32,17 @@ public enum RequestBodyBuilder {
             if !NSJSONSerialization.isValidJSONObject(object) {
                 let userInfo = [NSLocalizedDescriptionKey: "invalid object for JSON passed."]
                 let error = NSError(domain: APIKitRequestBodyBuidlerErrorDomain, code: 0, userInfo: userInfo)
-                result = Result.Failure(Box(error))
+                result = failure(error)
                 break
             }
-
-            var error: NSError?
-            if let data = NSJSONSerialization.dataWithJSONObject(object, options: writingOptions, error: &error) {
-                result = Result.Success(Box(data))
-            } else {
-                result = Result.Failure(Box(error!))
+
+            result = try { error in
+                return NSJSONSerialization.dataWithJSONObject(object, options: writingOptions, error: error)
             }
 
         case .URL(let encoding):
-            var error: NSError?
-            if let data = URLEncodedSerialization.dataFromObject(object, encoding: encoding, error: &error) {
-                result = Result.Success(Box(data))
-            } else {
-                result = Result.Failure(Box(error!))
+            result = try { error in
+                return URLEncodedSerialization.dataFromObject(object, encoding: encoding, error: error)
             }
 
         case .Custom(let (_, buildBodyFromObject)):

APIKit/ResponseBodyParser.swift

@@ -27,19 +27,13 @@ public enum ResponseBodyParser {
 
         switch self {
         case .JSON(let readingOptions):
-            var error: NSError?
-            if let object: AnyObject = NSJSONSerialization.JSONObjectWithData(data, options: readingOptions, error: &error) {
-                result = Result.Success(Box(object))
-            } else {
-                result = Result.Failure(Box(error!))
+            result = try { error in
+                return NSJSONSerialization.JSONObjectWithData(data, options: readingOptions, error: error)
             }
 
         case .URL(let encoding):
-            var error: NSError?
-            if let object: AnyObject = URLEncodedSerialization.objectFromData(data, encoding: encoding, error: &error) {
-                result = Result.Success(Box(object))
-            } else {
-                result = Result.Failure(Box(error!))
+            result = try { error in
+                return URLEncodedSerialization.objectFromData(data, encoding: encoding, error: error)
             }
 
         case .Custom(let (accept, parseData)):

APIKit/URLEncodedSerialization.swift

@@ -9,7 +9,7 @@ private func unescape(string: String) -> String {
 }
 
 public class URLEncodedSerialization {
-    public class func objectFromData(data: NSData, encoding: NSStringEncoding, inout error: NSError?) -> AnyObject? {
+    public class func objectFromData(data: NSData, encoding: NSStringEncoding, error: NSErrorPointer) -> AnyObject? {
         var dictionary: [String: AnyObject]?
 
         if let string = NSString(data: data, encoding: encoding) as? String {
@@ -26,19 +26,19 @@ public class URLEncodedSerialization {
 
         if dictionary == nil {
             let userInfo = [NSLocalizedDescriptionKey: "failed to decode urlencoded string."]
-            error = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
+            error.memory = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
         }
 
         return dictionary
     }
 
-    public class func dataFromObject(object: AnyObject, encoding: NSStringEncoding, inout error: NSError?) -> NSData? {
+    public class func dataFromObject(object: AnyObject, encoding: NSStringEncoding, error: NSErrorPointer) -> NSData? {
         let string = stringFromObject(object, encoding: encoding)
         let data = string.dataUsingEncoding(encoding, allowLossyConversion: false)
 
         if data == nil {
             let userInfo = [NSLocalizedDescriptionKey: "failed to decode urlencoded string."]
-            error = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
+            error.memory = NSError(domain: APIKitErrorDomain, code: 0, userInfo: userInfo)
         }
 
         return data

APIKitTests/RequestBodyBuilderTests.swift

@@ -60,15 +60,15 @@ class RequestBodyBuilderTests: XCTestCase {
     }
 
     func testCustomHeader() {
-        let builder = RequestBodyBuilder.Custom(contentTypeHeader: "foo", buildBodyFromObject: { o in Result.Success(Box(o as NSData)) })
+        let builder = RequestBodyBuilder.Custom(contentTypeHeader: "foo", buildBodyFromObject: { o in success(o as NSData) })
         XCTAssertEqual(builder.contentTypeHeader, "foo")
     }
 
     func testCustomSuccess() {
         let string = "foo"
         let expectedData = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
         let builder = RequestBodyBuilder.Custom(contentTypeHeader: "", buildBodyFromObject: { object in
-            return Result.Success(Box(expectedData))
+            return success(expectedData)
         })
 
         switch builder.buildBodyFromObject(string) {

APIKitTests/ResponseBodyParserTests.swift

@@ -65,15 +65,15 @@ class ResponseBodyParserTests: XCTestCase {
     }
 
     func testCustomAcceptHeader() {
-        let parser = ResponseBodyParser.Custom(acceptHeader: "foo", parseData: { d in Result.Success(Box(d)) })
+        let parser = ResponseBodyParser.Custom(acceptHeader: "foo", parseData: { d in success(d) })
         XCTAssertEqual(parser.acceptHeader, "foo")
     }
 
     func testCustomSuccess() {
         let expectedDictionary = ["foo": 1]
         let data = NSData()
         let parser = ResponseBodyParser.Custom(acceptHeader: "", parseData: { data in
-            return Result.Success(Box(expectedDictionary))
+            return success(expectedDictionary)
         })
 
         switch parser.parseData(data) {