曾小乱

// Generic Monad structure
class Monad {
  constructor(value) {
    this.value = value;
  }

  // Bind: chains computations that return a Monad
  bind(fn) {
    return fn(this.value);
  }

  // Unit: wraps a value in the Monad
  static of(value) {
    return new Monad(value);
  }

  // For debugging
  get() {
    return this.value;
  }
}

// Example: Maybe Monad
class Maybe extends Monad {
  bind(fn) {
    if (this.value == null) {
      return new Maybe(null);
    }
    return fn(this.value);
  }

  static of(value) {
    return new Maybe(value);
  }

  getOrElse(defaultValue) {
    return this.value == null ? defaultValue : this.value;
  }
}

// Demo: chaining computations with Monad
const double = x => Monad.of(x * 2);
const increment = x => Monad.of(x + 1);

const result = Monad.of(5)
  .bind(double)      // 10
  .bind(increment);  // 11

console.log(result.get()); // Output: 11

// Demo: chaining with Maybe Monad
const safeDivide = x => x === 0 ? Maybe.of(null) : Maybe.of(10 / x);

const maybeResult = Maybe.of(2)
  .bind(safeDivide)       // 10 / 2 = 5
  .bind(x => Maybe.of(x + 3)); // 8

console.log(maybeResult.getOrElse("fail")); // Output: 8

const maybeFail = Maybe.of(0)
  .bind(safeDivide)       // null
  .bind(x => Maybe.of(x + 3));

console.log(maybeFail.getOrElse("fail")); // Output: "fail"

class Maybe {
  constructor(value) {
    this.value = value;
  }

  // Functor map: applies a function if value is not null/undefined
  map(fn) {
    if (this.value === null) {
      return new Maybe(null);
    }
    return new Maybe(fn(this.value));
  }

  // getOrElse: safely extract value with a fallback
  getOrElse(defaultValue) {
    return this.value === null ? defaultValue : this.value;
  }

  // static helpers for convenience
  static of(value) {
    return new Maybe(value);
  }

  static nothing() {
    return new Maybe(null);
  }
}

// Example usage:
const maybeNumber = Maybe.of(5)
  .map(n => n * 2)
  .map(n => n + 1);

console.log(maybeNumber.getOrElse(0)); // Output: 11

const maybeNull = Maybe.of(null)
  .map(n => n * 2);

console.log(maybeNull.getOrElse(0)); // Output: 0

这几个月开始面试，里面就涉及到了怎么面试的问题，有人说你面试能力不行，那我的面试方法真的有问题吗？