3 key differences between Elixir and Ruby?

1. Programming paradigm. Elixir runs on the Erlang VM (BEAM) that has a totally different way of running things. Code is run in small processes that are pre-emptively scheduled. This means you can easily take advantage of parallelism without being able to hog a core/scheduler, and you can write blocking code without having to worry about it blocking some other code from running.
2. Functional programming with immutable values. Changes the way you think, for the better IMO.
3. Pattern matching. I use it in conditionals, I use it in function heads, I use it in assignments. It makes my code more readable and helps guard against (runtime) type errors, failing fast instead of running with a possibly wrong value and crashing far away from the problem site. Now to be honest I haven’t played with Ruby much so I don’t know how they mitigate that.

1. No return - it is a challenge at first,
   but very rewarding once you learn to live without it.

2. No member variables or inheritance - all the parameters to your function are explicitly passed in, much clearer!

3. Library ecosystem built for concurrency - ever been bitten by a Gem that wasn’t threadsafe? Works in dev/test then fails when running in Puma. Not in Elixir

• Pattern Matching & Multiple arity functions
  I now wish every language had this, it’s de-structuring, plus sort of a powerful “value/format-enforcement” mechanism (pattern) that can be used anywhere, function declarations, case’s, assignment, etc. The clarity might not be obvious at first but really becomes obvious once you need to keep adding functionality.

• Direct access (sometimes cleaned up in terms of boilerplate) to Erlang’s OTP Abstractions and Tools, like gen_server and ETS. These two alone allow a sh**load of stuff to be done in relatively simpler ways.

These 2 are things I constantly use - one in terms of writing in the language the other in terms of architecting with the language.

Then the traditional, runs on the beam, etc etc etc, but there’s plenty of other stuff…

You can btw work without implementation inheritance / subtype polymorphism in oo languages. Recommended.
Paper Do We Need Inheritance? from Wolfgang Weck and Clemens Szyperski:
https://pdfs.semanticscholar.org/3d49/436db0516018018aca6e17e9a0ca68db25ca.pdf

Completely agree with point number 2. It’s crazy how much just one week of trying to learn Elixir has changed they way I think about programming. Things that used to seem normal just seem plain wrong now, in particular passing/mutating collections by passing their reference to a separate method just feels gross to me now. After using Elixir it seems so obvious how much cleaner it is to just match a new variable to the output of the function, but I didn’t even give it a second thought for my first three years as a programmer.

Haven’t even gotten in to the stuff from #2 yet but I can’t wait to see everything Elixir is capable of, but I whole heartedly agree with pattern matching / multiple arity being a game changer. I genuinely got excited when I was watching a tutorial and saw someone type this line:

“def calculate(arr) when length(arr) <= 1 do”

Never seen anything quite like it before.

While being present in Ruby with Lambdas, I find really nice to play with functions. I guess it’s one good side of functional programming. By extension, I also enjoy the pipe operator, so common in unix shell, and the with construct…