Nesting vs Chaining

tip

Chaining is better than nesting in terms of readability

kotlin-nesting.kt

stream1
    .flatMap {
        stream2.flatMap {
            stream3.flatMap {
                stream4
            }
        }
    }
    .collect()

kotlin-chaining.kt

stream1
    .flatMap { stream2 }
    .flatMap { stream3 }
    .flatMap { stream4 }
    .collect()

node-nesting.js

const makeBurger = nextStep => {
    getBeef(function(beef) {
        cookBeef(beef, function(cookedBeef) {
            getBuns(function(buns) {
                putBeefBetweenBuns(buns, beef, function(burger) {
                    nextStep(burger);
                });
            });
        });
    });
};

node-chaining.js

const makeBurger = () => {
    return getBeef()
        .then(cookBeef)
        .then(getBuns)
        .then(putBeefBetweenBuns);
};

makeBurger().then(serve);