What are some examples of monads in JavaScript?

What are some examples of monads in JavaScript?

Monads in JavaScript can be illustrated with examples like the Maybe Monad, Promise Monad, and the Either Monad. Would you like to see a specific example?

Yes, can you explain the Maybe Monad?

Sure! The Maybe Monad is used to handle values that may be null or undefined. It encapsulates a value and provides methods to work with it safely. For example, you can use map to apply a function only if the value is present.

Can you show me a code example of the Maybe Monad?

Absolutely! Here's a simple implementation:

class Maybe {
    constructor(value) {
        this.value = value;
    }
    static of(value) {
        return new Maybe(value);
    }
    isNothing() {
        return this.value === null || this.value === undefined;
    }
    map(fn) {
        return this.isNothing() ? this : Maybe.of(fn(this.value));
    }
}

const maybeValue = Maybe.of(5);
const result = maybeValue.map(x => x * 2);
console.log(result); // Maybe { value: 10 }

That's really helpful! What about the Promise Monad?

The Promise Monad is used for handling asynchronous operations. It represents a value that may be available now, or in the future, or never. You can chain operations using then. Would you like to see a code example for that?