Learning Elixir: Part 3

Hi All, Wow, we're already at part 3 and we're barely scratching the surface. I see a long road ahead with so much more learning to do. On the more positive side; I'm getting it and I'm finding it quite enjoyable so far... so let's crack on, shall we?

In the last few days I did two more experiments to do some basic sending and receiving between erlang processes (which I've come to find is a term which is interchangeable with BEAM processes, which is what I really mean).

My first task was to build a function (based on the video I linked to in part 1) that did some distributed work. So for this, I declared a function that took a list and a function and then the function would be applied to each item in the list. This was somewhat similar to a map() function in functional programming. Here's the Elixir part, each function would be run inside it's own Erlang process. Neato.

https://gist.github.com/samjarman/de7dd2337b425d1499cce16d0f1a5831

So, walking through the code, first we make a reference to the process by calling it me. Then on the list, we then map over the list, creating a function that spawns a process, which inside that sends back to the parent process a PID (self) and the result of applying the function to the element. Then on that list of PIDs we receive the result, and presto-we have a list of results. Pretty neat. With the task above, what wouldn't work is if the process was more complex (say, not multiplying a number by itself) and the process was to error out, nothing would rescue that... so that leads me to my next task.

My second task was to start playing with the concept of supervision, a reasonably crucial one in Elixir. I wanted to implement from scratch a really simple supervisor that would look at a randomly failing process and make sure it stayed alive.

https://gist.github.com/samjarman/7043ac55e9518969c8c1839d670d9622

So what I've done here is declared a worker function which fails just a little bit of the time, and if it does, it'll tell it's master about it before exiting. If the master hears about this, it'll respawn it and start listening all over again. Take a read through the code.

My next task is to start implementing some proper Elixir projects. There are also a few good ones to contribute to out there. If you have any suggestions for projects... I'm all ears!

Have you also been learning Elixir or Erlang too? Do you have any tips or comments? I’d love to hear them and share them in an upcoming post. Ping me on twitter.

Learning Elixir: Part 2

Hey All, Thanks for reading my last post - since then I've been doing a little more hacking and watching.

I believe the important thing with learning a new programming language is to focus on its strengths and weaknesses rather than just the syntax difference. Syntax is something you can learn quickly, but knowing the strengths and weaknesses of any language of tool can take an indeterminate amount of time.

Resources

I prefer to learn by really getting into the head of the people who came up with the language. One of those is Robert Virding, one of the original team members who worked on Erlang at Ericsson.

Here's a talk by him describing the Rationale of Erlang.

https://www.youtube.com/watch?v=rt8h_xeESLg

001

Another great resource is The Zen of Erlang. This (long) read covers some of the core principles and the mindset of Erlang (all of which are applicable to Elixir) Some other things I plan to watch and read are Learn You Some Erlang and this other talk by Virding. I was also suggested a book called The Little Elixir and OTP Guide Book. Do you have any more to add to this list? Let me know.

I had some more progress to talk about in this post, but I'll leave it for next time in the interest of keeping these posts short and to the point.

Have you also been learning Elixir or Erlang too? Do you have any tips or comments? I'd love to hear them and share them in an upcoming post. Ping me on twitter.