Advanced Functional Programming with Elixir (PragProg)

Alright, another one to add to the library!

P.S. Need to add “www” in the link to the author’s personal site.

Perfect timing! Just finished Ulisses Almeida “Learn Functional Programming with Elixir” and this new book by Joseph Koski feels like the natural next step.

Thanks for pointing out the fix needed to the URL. We’ve updated it.

Amazing! Thank you so much! Looking forward to this!

Looks like a great entry to the PP Elixir lineup. I look forward to lighting up a pipe or cigar and taking it in.

I really hope our community embraces functional programming idioms. Whenever I see a globally named process being used as a singleton in OOP gives me goosebumps.

I really like the cover, im sold on the book

Yeah, we often treat functional programming as all or nothing, but really it is just a set of patterns and abstractions. You can start with a couple of simple ones and stop there. And there is no need to rewrite the codebase. It is easy to cut into a functional abstraction when it helps, then cut back to idiomatic Elixir.

Also, I would not claim that every codebase should use functional programming. However, I would suggest that knowing patterns makes for better developers.

On a scale of 1-10 , would you recommend this book for someone who considers themself a “working man programmer” and not really reading for the theory or intellectual stimulation.

Ive tried reading functional programming books b4 and I have gotten some gems out of them, my fav is building functions that follow 3 steps.

1. the fn should only return a single thing
2. a fn calculates its return based on its arguments values
3. the function cannot mutate existing values

Those rules has helped me to build things cleanly like lego, but I will admit I rarely think of fp and elixir isnt as strict as something like haskell when it comes to fp, you can pretty much hack your way around thanks to the actor model and also otp laying alot of ground work so you cant really mess up. Sure with fp writing declarative code is a dream, things being immutable by default is also great. but what is the bigger picture of getting more in tune with fp for elixir? I rarely hear the elixir comm focusing on FP culture

I am a bit turned off by the fact we are using an external library to learn said concepts, does that mean using elixir primitive’s to build up such machinery in a normal setting, is ehh ceremonial and not done often? I am most likely going to buy it cause I like the cover & its 30 bucks, but can you give me like a cool example that would wow me away and also tie it with the actor model

I appreciate how much you put into your comment. You raise solid points that deserve a proper reply.

Once upon a time, I taught music at a university. We had evidence, which was eventually published in Peak, that mastery requires three basic parts. One, we need to work just beyond our current skill level. Two, we need continuous and consistent feedback. Finally, we need someone to light the path, someone to show us the quickest way forward.

I would make the argument that while FP patterns are not appropriate for every codebase, knowing them is helpful. Sort of like having a student work hard to master patterns in all keys. It is really hard to perform in odd keys when those patterns are not under your fingers. The same is true in Elixir. You may not reach for these abstractions every day, but when you encounter logic that involves optional values, layered validations, or context-aware computations, it helps if the patterns are already familiar.

In the world of Google, Wikipedia, and now LLMs, a book needs to earn its keep and its price tag. Mine included. It is easier than ever to find information on functional programming, but it is still hard to sort out the learning path. My book’s value proposition is that it saves time. It shows what to practice, in what order, and why it matters. It helps focus attention, avoid common missteps, and move forward with purpose.

I like that you asked for a wiz bang finish. I will give it my best shot. My goal has been to remove barriers to learning functional programming, which takes more than just writing a book. I have been building a larger ecosystem that I have been slowly releasing to friends. If you have access to a more powerful LLM, such as Claude Code, you can ask me your questions directly through this project: AI Tutor for Functional Programming - Funx . I would love to hear what you think if you give it a try.