Sunday, May 13, 2018

Thoughts On Working With Nested Monad Within The Future Monad In Scala

This post is about nested contexts, specifically with Future, or more accurately, nested monad within the Future monad. eg: Future[Either[E, A]], Future[Option[A]] etc. And how such nested context could easily lead to hard to read and hence hard to maintain codebase.

These sort of context nesting and its impact is not limited to Future, but I would be using Future as the reference in this post, strictly because they seem to be the form that appears the most in a particular Scala codebase I work on at my day job.

Also in this post, I would use Monad and Context interchangeable to mean the same thing. I would also mention terms like Monads, Monad Stack, Monad Transformers, or For Comprehension without providing any explanation of these terms. This is because the thrust of this post is not to expound on these concepts but to share some recent thoughts I have been having regarding nested context within Future.

A reader not familiar with these concepts should still be able to follow along though.