Swift Language Typealias typealias for closures with parameters
Example
typealias SuccessHandler = (NSURLSessionDataTask, AnyObject?) -> Void
This code block creates a type alias named SuccessHandler, just in the same way var string = "" creates a variable with the name string.
Now whenever you use SuccessHandler, for example:
func example(_ handler: SuccessHandler) {}
You are essentilly writing:
func example(_ handler: (NSURLSessionDataTask, AnyObject?) -> Void) {}
