One could argue that they compete in the same space; they target the programmer who is learning Elixir but they do have a different emphasis once you get past the introductory material.
To me Programming Elixir feels more like a tour of “Elixir, the Language” with some basic “functional programming is quite different” lessons. Elixir in Action drives briskly forward with FP, then gets BEAM-y by discussing the concurrency primitives to then quickly switch over to GenServers and Supervisors and how to build applications with them (Chapter 11.3 Building a Web Server). Of course there are tradeoffs - for example Programming Elixir discusses how to program some basic macros while Elixir in Action merely acknowledges their existence (Don’t Write Macros But Do Learn How They Work). Elixir in Action pursues “thinking and programming BEAM-style” much harder which I personally like but that isn’t necessarily to everybody’s liking or benefit.
I have a friend that has the first edition, is the second edition worth getting or I’ll be fine with the first?
Some of the “drawbacks” are highlighted in
What should I keep in mind if I'm using Elixir in Action today? (i.e. pre-2e)
There’ll likely be multiple opportunities this month to score a 50% discount on the manning site - if you are going to spend your time working with it, it’s likely worth to get hold of the updated version given that Elixir has evolved quite a bit since 2015. Depending on how far you have progressed with Programming Elixir you may be able to drop in at Chapter 5 Concurrency Primitives to then quickly get to the meat of things.
