Update readme

README.md

@@ -64,10 +64,8 @@ state and then could be resolved with a value or rejected with an error.
 ```swift
 // Creates a new promise that could be resolved with a String value
 let promise = Promise<String>()
-
 // Resolves the promise
 promise.resolve("String")
-
 // Or rejects the promise
 promise.reject(Error.notFound)
 ```
@@ -80,7 +78,7 @@ let promise = Promise({
 ```
 
 ```swift
-// Creates a new promise that is rejected with an ErrorType
+// Creates a new promise that is rejected with an Error
 let promise = Promise({
   //...
   throw Error.notFound
@@ -96,48 +94,62 @@ let promise = Promise<String>(queue: dispatch_get_main_queue())
 ```
 
 ### Done
-Add a handler to be called when the ***promise*** object is resolved with a value:
+Adds a handler to be called when the ***promise*** object is resolved with a value:
 
 ```swift
 // Create a new promise in a pending state
 let promise = Promise<String>()
-
 // Add done callback
 promise.done({ value in
   print(value)
 })
-
 // Resolve the promise
 promise.resolve("String")
 ```
 
 ### Fail
-Add a handler to be called when the ***promise*** object is rejected with
-an `ErrorType`:
+Adds a handler to be called when the ***promise*** object is rejected with
+an `Error`:
 
 ```swift
 // Create a new promise in a pending state
 let promise = Promise<String>()
-
-// Add done callback
+// Add fail callback
 promise.fail({ error in
   print(error)
 })
-
 // Reject the promise
 promise.reject(Error.notFound)
 ```
 
+It's also possible to cancel a promise, which means it will be rejected with
+`PromiseError.cancelled` error. `FailurePolicy` can be used if you want to
+ignore this error in your `fail` handler:
+
+```swift
+// Create a new promise in a pending state
+let promise = Promise<String>()
+// This callback will not be called when a promise is cancelled
+promise.fail({ error in
+  print(error)
+})
+// This callback will be called when a promise is cancelled
+promise.fail(policy: .allErrors, { error in
+  print(error)
+})
+// Cancel the promise
+promise.cancel()
+```
+
 ### Always
-Add a handler to be called when the ***promise*** object is either resolved or
+Adds a handler to be called when the ***promise*** object is either resolved or
 rejected. This callback will be called after [done](#done) or [fail](#fail)
 handlers.
 
 ```swift
 // Create a new promise in a pending state
 let promise = Promise<String>()
-
-// Add done callback
+// Add always callback
 promise.always({ result in
   switch result {
   case let .success(value):
@@ -146,7 +158,6 @@ promise.always({ result in
     print(error)
   }
 })
-
 // Resolve or reject the promise
 promise.resolve("String") // promise.reject(Error.notFound)
 ```