如何定义不同模式的typescript接口？

interface Person {
  firstName: string;
  lastName: string;
}

const person: Person = {
  firstName: "John",
  lastName: "Doe"
};

interface Greeter {
  greet(name: string): string;
}

const greeter: Greeter = {
  greet(name) {
    return `Hello, ${name}!`;
  }
};

interface Person {
  firstName: string;
  lastName: string;
  middleName?: string; // 可选属性
}

const person: Person = {
  firstName: "John",
  lastName: "Doe"
};

interface Point {
  readonly x: number;
  readonly y: number;
}

const point: Point = { x: 10, y: 20 };
// point.x = 5; // 错误，只读属性不能被修改

interface StringDictionary {
  [key: string]: string;
}

const dict: StringDictionary = {
  key1: "value1",
  key2: "value2"
};

interface StringValidator {
  (str: string): boolean;
}

const isEmail: StringValidator = (str) => {
  return str.includes('@');
};

type UserId = string | number;

interface User {
  id: UserId;
  name: string;
}

const user: User = {
  id: "123",
  name: "John Doe"
};

interface Named {
  name: string;
}

interface Person extends Named {
  age: number;
}

const person: Person = {
  name: "John",
  age: 30
};