promises-spec VS algo.monads

Today, I tried implementing Promises/A+ from scratch to test my coding skill. In the process, I’ve crafted this guide to share my insights and experiences with those who share a similar interest. Without further ado, let’s dive in.

That made me chuckle.

For those not familiar with the promise design controversy:

http://brianmckenna.org/blog/category_theory_promisesaplus

https://github.com/promises-aplus/constructor-spec/issues/24

https://github.com/promises-aplus/promises-spec/issues/94

If you really want to go down the rabbit hole on this one, start here

Advantage 1, nesting, is the most important here, and it's often the most-overlooked advantage. Overlooking nesting is how Promises in Javascript got to be fundamentally broken.

Have you read the infamous GitHub thread where people tried to fix this before it got finalized? It's quite a trip

1.) JS implementation of Promise is not a monad. See this StackOverflow answer or this GitHub discussion for more details

In this article, we will go over how to implement a basic version of a promise during a FAANG interview. The standard for promise implementation is called A+, but it includes a huge amount of details, making it almost impossible to implement all of them during a one-hour coding interview. Therefore, we will focus on implementing a basic variation that should be enough to show the interviewer your solving skills.

Hey, at least you weren't these guys: https://github.com/promises-aplus/promises-spec/issues/94

Total carnage

Clojure is a partially lazy, functional lisp, that has some very neat abstractions underlying its core library. It doesn't have explicit monads builtin, but here's a great implementation that also has some educational material: https://github.com/clojure/algo.monads