1、filter
2、??
3、try!
4、first
5、DispathQueue.main.async { [weak self] in
6、is
7、as
8、case is xxx
9、case let a as xxx
10、Any
11、#selector
12、DispatchQueue.global(qos: .userInitiated).async {
13、_
14、DispatchQueue.main.sync {
15、#available
16、
func start(_ message: String, completion: @escaping () -> Void) {
17、
func start(_ message: String, completion: @escaping () throws -> MessageHandle?) {
18、
func done(completion: (() -> Void)? = nil) {
标签：completion,String,语法,start,func,整理,DispatchQueue,swift From： https://www.cnblogs.com/cchHers/p/17110325.html