08 # 接口：函数类型接口

let addFunc: (x: number, y: number) => number;

interface AddFunc1 {
    (x: number, y: number): number;
}

type AddFunc2 = (x: number, y: number) => number;

let add1: AddFunc1 = (x, y) => x + y;
let add2: AddFunc2 = (x, y) => x + y;

interface Lib {
    (): void;
    version: string;
    doSomething(): void;
}
function getLib() {
    let lib: Lib = (() => {}) as Lib;
    lib.version = '1.0.0';
    lib.doSomething = () => {}
    return lib;
}
let lib1 = getLib();
lib1();
lib1.version;
lib1.doSomething();