RunElixir.com - A free, 30min Elixir Quickstart Guide

Thanks for this @PJUllrich

I added a new chapter today: In-memory State!

I explain how to use Agents, ets, dets, or persistent_term to store state in your Elixir application. I also added Big-O complexities for ets and persistent_term where possible. Check it out!

image1200×683 27.3 KB

Thanks, that’s neat.

Currently I am going through “Lists and Tuples”. I’m not sure if it’s good to have multiple lines in one livebook block and not be possible to evaluate each line on its own… If someone looks at that on a small device, he has to scroll down, up, down, up,… and associate each result to the correct line. Have you already put some thought into this? (Edit: I see now, that you put the number als label therefore. Maybe it’s better to put a short description there? As “get 2nd element”…)

Also, I would mention the Elixir version very soon. I know Elixir doesn’t change much these days, but someone with little experience with Elixir doesn’t know that. Personally, I wouldn’t use a JavaScript, Go or Rust guide if I didn’t know what version it was written for (maybe it’s out of date), so I would mention the version right in the beginning and also that the guide will be close to correct even if the reader’s version is not too far in the future. (Plus a link where to inform you if anything isn’t working anymore → Github?).

Thanks! Yes, I thought about that A LOT unfortunately, that’s the only way I found in which the user can still run the Livebook block and get a response from all function calls. If I create one block per call, the doc becomes too long. I could remove all the IO.inspect calls which I don’t like either and show the response in a comment somehow. That might be better but it’s not great either. If you have a suggestion, please feel free to send a PR

Good work! I am almost a complete newbie at Elixir, so it’s possible my comment is inaccurate but maybe others like me will have a question about this:

Working through the material I reached the Pattern Matching section. Here for (I think) the first time I encountered the “->” operator (is it even an operator? ) . It appears in the fragment

map_empty? = fn
  %{} -> true
  _ -> false
end

I didn’t know what that meant, so perhaps a bit of explanation there would be good.
Thanks

This is a standard syntax for anonymous function (fn x -> x * 2 end) but here the function has two clauses.

Sidenote: I have no idea where this snippet has been taken from, but the name is extremely misleading, I cannot think of a way to use this function to actually check if the map is empty.

Sidenote 2: there are no operators in Elixir at all.

It’s from the pattern matching section, and it’s actually part of a note exactly about why it doesn’t work, and gives two options for actually determining if the map is empty.

I know what you mean, but it seems like even the Elixir docs use the term “operator”. Erlang also does.

Than you @forestial for the valuable feedback! I’ve updated that section with a better example and added more information for multiple clauses in anonymous functions to the Pattern Matching section

@mudasobwa aren’t things like +, =, |>, <= etc. called operators? For example, the official Elixir docs call |> “the pipe operator”.

Well, it’s all a matter of wording but technically + and company do not differ from functions syntactically or semantically. Moreover, they are indeed functions.

Very cool guide/intro. 30 min seems rather optimistic though