add .success / .failure methods that cause sideeffects only

SwiftTask/SwiftTask.swift

@@ -198,6 +198,20 @@ public class Task<Progress, Value, Error>: Cancellable, CustomStringConvertible
         })
     }
 
+    ///
+    /// creates rejected task with ErrorInfo
+    ///
+    /// - e.g. Task<P, V, E>(errorInfo: someErrorInfo)
+    ///
+    internal convenience init(errorInfo: ErrorInfo)
+    {
+        self.init(_initClosure: { machine, progress, fulfill, _reject, configure in
+            _reject(errorInfo)
+        })
+
+        self.name = "RejectedTask"
+    }
+
     /// internal-init for accessing `machine` inside `_initClosure`
     /// (NOTE: _initClosure has _RejectInfoHandler as argument)
     internal init(weakified: Bool = false, paused: Bool = false, _initClosure: _InitClosure)
@@ -447,6 +461,26 @@ public class Task<Progress, Value, Error>: Cancellable, CustomStringConvertible
         }
     }
 
+    ///
+    /// success (fulfilled) + closure returning nothing
+    /// used as transparent (i.e. it doesn't affect passed Task) handler.
+    ///
+    /// - e.g. task.success { value -> Void in ... }
+    ///
+    public func success(successClosure: Value -> Void) -> Task
+    {
+        var dummyCanceller: Canceller? = nil
+        return self.success(&dummyCanceller, successClosure)
+    }
+
+    public func success<C: Canceller>(inout canceller: C?, _ successClosure: Value -> Void) -> Task
+    {
+        return self.success(&canceller) { (value: Value) -> Task in
+            successClosure(value)
+            return Task(value: value)
+        }
+    }
+
     ///
     /// success (fulfilled) + closure returning **value**
     ///
@@ -496,6 +530,28 @@ public class Task<Progress, Value, Error>: Cancellable, CustomStringConvertible
         }.name("\(self.name)-success")
     }
 
+    ///
+    /// failure (rejected or cancelled) + closure returning nothing
+    /// used as transparent (i.e. it doesn't affect passed Task) handler.
+    ///
+    /// - e.g. task.failure { errorInfo -> Void in ... }
+    /// - e.g. task.failure { error, isCancelled -> Void in ... }
+    ///
+
+    public func failure(failureClosure: ErrorInfo -> Void) -> Task
+    {
+        var dummyCanceller: Canceller? = nil
+        return self.failure(&dummyCanceller, failureClosure)
+    }
+
+    public func failure<C: Canceller>(inout canceller: C?, _ failureClosure: ErrorInfo -> Void) -> Task
+    {
+        return self.failure(&canceller) { (errorInfo: ErrorInfo) -> Task in
+            failureClosure(errorInfo)
+            return Task(errorInfo: errorInfo)
+        }
+    }
+
     ///
     /// failure (rejected or cancelled) + closure returning **value**
     ///