swift - Swift 语法 ".bar"叫什么？

Question

Swift 有这个方便的语法:

enum Foo {
    case bar
    case baz
}


func hoge(foo: Foo) {
}


hoge(foo: .bar) // This

在 enum 以外的地方进行镜像:

struct Qux {
    static let `default` = Qux()
}


func hoge(qux: Qux) {
}


hoge(qux: .default) // This

我不确定在对话/工单中如何调用它。也许是“类型推断的点语法”？我不确定。 这个语法有正式名称吗？如果有，它是什么？

Answer 1

它被称为隐式成员表达式。来自 the grammar section of the language guide :

An implicit member expression is an abbreviated way to access a member of a type, such as an enumeration case or a type method, in a context where type inference can determine the implied type. It has the following form:

.member name

For example:

var x = MyEnumeration.someValue
x = .anotherValue