请问ngrx的auth.actions文件的这句export是什么意思？

Question

export enum AuthActionTypes {
  Login = '[Auth] Login',
  Logout = '[Auth] Logout',
  LoginSuccess = '[Auth] Login Success',
  LoginFailure = '[Auth] Login Failure',
  LoginRedirect = '[Auth] Login Redirect'
}

export type AuthActions =
  | Login
  | LoginSuccess
  | LoginFailure
  | LoginRedirect
  | Logout;

第二个export是什么意思？ “|” 是什么语法？

Answer 1

AuthActionTypes是一个枚举，包括5个可选值
export是导出类型
竖线语法叫做 String Literal Types

String Literal Types
String literal types allow you to specify the exact value a string must have. In practice string literal types combine nicely with union types, type guards, and type aliases. You can use these features together to get enum-like behavior with strings.

也就是AuthActions虽然是字符串，但是只能取以上枚举的那几个值之一

具体看
http://www.typescriptlang.org/docs/handbook/advanced-types.html