1. // let add: (x: number, y: number) => number
    3. // interface Add {
    4. //   (x: number, y: number): number
    5. // }
    7. // type Add = (x: number, y: number) => number
    9. // let add: Add = (a, b) => a + b
    11. interface Lib {
    12.   (): void;
    13.   version: string;
    14.   doSomething(): void;
    15. }
    17. function getLib() {
    18.   let lib: Lib = (() => { }) as Lib;
    19.   lib.version = "1.0";
    20.   lib.doSomething = () => { };
    21.   return lib;
    22. }
    24. let lib1 = getLib();
    25. lib1();
    26. lib1.doSomething();
    27. let lib2 = getLib();