An animated introduction to Elixir

https://markm208.github.io/exbook/

by ingve • 4 years ago

308 95 4 years ago

markm208.github.io

whalesalad• 4 years ago

This is very neat. For a while I’ve wanted to create a visual wysiwyg editor for creating/visualizing supervision trees in Elixir/Erlang - love to see visualizations. (The observer is epic)

ch4s36• 4 years ago

That exists in LiveBook now[1] as part of some visualization improvements.

[1] https://news.livebook.dev/whats-new-in-livebook-0.7-2wOPsY

ipnon2• 4 years ago

Phoenix with LiveView is an antidote to the pernicious Web we weave. Massive concurrency, hydration, and that ever elusive stateful single page app experience, are all handled at the framework level instead of in the application. You write the app and it Just Works. If React or the JavaScript du jour isn’t already your horse in the race, Elixir is well worth a weekend test drive.

gorgoiler• 4 years ago

Do you have a link to something that’s shipped with these technologies?

ch4s36• 4 years ago

I think https://www.cars.com/ is largely done with LiveView now.

throwawaymaths2• 4 years ago

Discord uses elixir quite a bit. I believe pagerduty as well.

whoooooo123• 4 years ago

Elixir has some case studies written up on its official site.

https://elixir-lang.org/cases.html

Also there's https://elixir-companies.com/en

ch4s36• 4 years ago

It even have a jupyter competitor in LiveBook[1].

[1] https://livebook.dev/

AlchemistCamp6• 4 years ago

Unfortunately VIM bindings are a non-goal, so I’m not going to be spending much time with it (due to a history of RSI).

timc36• 4 years ago

It doesn’t just work in my experience. Once its working it is fine, better than fine in fact. But I am going through a process of upgrading a Phoenix LiveView hobby site and its been miserable.

For some reason LiveView has changed between versions, and the documentation isn’t the greatest on explaining why or what to do to remedy it, but its broke my app. I’ve managed to fix the majority of it but then the third party libraries used have not kept up (for authentication of all things). There is so little people using Elixir/Phoenix/LiveView that libraries are often poor quality and maintained by one person or very few people. It makes me miss Django for the batteries included completeness, quality of documentation and eco system.

Phoenix also feels a little bit magical in the way Rails is, and I hated Rails for that. Give me configuration over convention and stop with the damn macros.

I am also not convinced with Elixir as a language, I miss types, I miss C# and Typescripts documentation or the fact they feel well designed, I want something to replace Python as my goto and Elixir just feels like a dead end that happens to have a web framework with some excellent ideas.

So I am currently thinking of rewriting the whole damn thing and leaving Elixir.

ipnon2• 4 years ago

I agree with your assessment. You have to know what you’re signing up for. Remaining in the JavaScript ecosystem still maintains many tangible benefits.

throwawaymaths2• 4 years ago

Yeah you got bitten by the 0.15-0.16 transition in live view. My condolences.

Documentation across the elixir ecosystem is pretty good, I find. I am way more comfortable in elixir ecosystem docs over python ecosystem docs.

conradfr6• 4 years ago

I don't think you should be downvoted, you gave it a fair shot and concluded it was not for you.

weatherlite2• 4 years ago

What's "magical" about Rails...I really dislike that criticism because it's an inaccurate cliche. Rails has great documentation and common sense (for the most part) conventions. Try doing something in Spring and tell me your experience ... it can easily be described as "magic" unless you read a massive amount of Spring documentation.

Existenceblinks2• 4 years ago

Elixir docs is top-notch, well-organized. Typescript docs is a mess category-wise. Believe it or not Typescript code is going to be buggy than dynamic typed elixir code because it has better defensive mechanism (pattern match + guard + immutability). The only thing I agree is macro, it's designed for human DX .. good though is hard to do interop (programmable).

h0l0cube4• 4 years ago

Phoenix also feels a little bit magical in the way Rails is

I've felt this about every backend web framework I've encountered, Django included. There's a tension between reducing boiler-plate, and not having directory structures/symbol names/etc. have some implicit order to them. If you want explicitness, don't use a framework and maybe use something like Flask/Werkzeug

I miss types

Most frameworks have typespecs defined which are enforced by dialyzer, using a much richer type system than most. e.g. Without creating some explicit enum you can make a function signature like:

@spec some_function() :: {:error, :bad_args | :out_of_bounds } | {:ok, SomeStruct.t}

And then you can a caller can just pattern match on that with a 'case' statement, and dialyzer will complain if all paths aren't handled.

I miss C# and Typescripts documentation

hexdocs.pm is pretty amazing. Elixir as a language encourages documentation and has iterated heavily on its documentation tooling. I love that I can just fire up an iex console and go `h Module.some_command` and I'll get great docs back. And then `@doctests` that both work as inline unit tests as well as low-cost documentation for the library author. I think the incentives to make good documentation are there, and that has inspired the community to document well. And then there's elixirforum.com if I get stuck. In constrast, many times a Django extension has left me wanting in its description about intended behaviours.

josevalim8• 4 years ago

I am sorry that this has been your experience.

I am obviously biased but I would stick around. :) I assume you started with LiveView early on, which means the documentation was sprouting and best practices still evolving.

Nowadays it is still pre-1.0 but much closer to its vision, so you should find better docs on the current practices. We now support components too, which declare each attribute, alongside their docs and types. So assuming you go through the update, I am hoping you will have a good time once it is done. And don’t hesitate to reach out in ElixirForum.com if you have questions.

Regarding types, we are researching types for Elixir: https://elixir-lang.org/blog/2022/10/05/my-future-with-elixi... - this is still years ahead, but I thought I would mention in context.

mattbrewsbytes• 4 years ago

Your assessment is similar to mine, set aside any cool features of the language, maintaining an Elixir app is the problem. The constant API shift with each LiveView release, not enough people maintaining hex packages, not a large amount of hex packages available forcing some things to be built, etc. Adoption in our organization was halted because of the messiness of upgrade path in Elixir as a whole. Projects that were built on earlier versions suffer the most pain where developers will spend like a week sorting through code changes needed to update. There are some neat aspects of Elixir but the maintenance trade-offs aren't worth it in management's eyes.

OkayPhysicist2• 4 years ago

LiveView's growing pains were definitely pretty bad (the early days of it had some pretty obnoxious breaking changes), and I can see while still disagreeing about the magic comment, but what's wrong with Elixir's docs? They are, hands-down, the best language docs I've ever interacted with, and that very much includes C#, so I'm a little baffled as to where that complaint comes from.

weatherlite2• 4 years ago

If React or the JavaScript du jour isn’t already your horse in the race,

If only it were up to us simple devs who actually do the work. But its not. CTOs make the decisions and they bring in tech that "everyone else" is using. That means Java/Node/Python/C#/ and Angular/React is probably 90% of web code out there. I can try fighting the trend and specifically apply to niche tech jobs but its no fun...been doing that with Ruby for awhile until jobs literally dried up where I live. If you live in a remote friendly area (big parts of Europe) you can get by .. but I don't.

tifadg1• 4 years ago

As someone completely new to js world, I've started learning nextjs and for hobby projects atleast I've come to the conclusion that negative opinions about js are overblown - yes theres not one dominating framework, but that's how innovation is born. Plus they're all about dev experience - you don't have to migrate if you're happy with what you've got.

Controversially I'm also pleased about breaking changes if it means things get significantly better and there's less legacy to deal with.

All in all a fast-paced ecosystem for a fast-paced world.

I did seriously give it a try with elixir but felt I wouldn't appreciate it without dealing with js first, so it'll be something if I ever outraged with js, but between typescript, nextjs, jsx templates and all the excellent vscode tooling I'm happy. Infact much happier than dealing with Django's black magic.

tartoran• 4 years ago

How’s the job market for elixir? It seems a lot of stacks are popular due to their employability.

lawik• 4 years ago

Not as straight forward as the massive languages as the pool of developers and work are both smaller. But remote EU or US is not very hard if you have some experience (Elixir or in general).

Junior positions are quite uncommon and seem to require some hustle on the networking side.

Market seems to be cooling a bit for consulting (I do that) as the economy makes companies more careful.

None of the highly motivated Elixir devs I know are struggling to find work. Consulting/contract clients has been trickier lately but not impossible.

Source: I help companies connect with Elixir devs as a specialist recruiter. And I do contracting/consulting.

Feel free to ask questions here or via contact through underjord.io

e3bc54b22• 4 years ago

Tangential, but what's the best way to get Elixir dev environment with database on Windows?

A friend and I have been trying it for a project and for a NixOS dweller like me it was less than 2 minutes of work. But for her it has been never ending troubles.

Otherwise, Elixir and Phoenix are fantastic! No explicit JavaScript is necessary and that alone sells it for me, but the concurrency story is so easy to grok that I'm amazed nobody else managed to recreate it in so many years..

AlchemistCamp6• 4 years ago

My company has a lot of Windows users due to its industry.

I’ve made a doc for setting up Windows machines that I’ve been planning to share online but haven’t gotten around to yet. I’ll try to tonight and update this thread with a link.

Tldr; use WSL2 and Ubuntu stable. Use ASDF. Put your app on the Linux part of the filesystem and if your Postgres installation is also on the Linux side, then have bash start it for you.

conradfr6• 4 years ago

It used to work on Windows but for some reasons nowadays I get trouble to make Elixir works with the OTP version the installer gets.

I couldn't get Elixir 1.14 to work in September actually and reverted to 1.13.4, maybe I should try again.

josevalim8• 4 years ago

Make sure you are also running Erlang/OTP 25. I will try to make this clearer in the installer!

marcus_cemes• 4 years ago

I've been using WSL, which you can get from the Store now. Works for development and building releases, which then deploy to an Ubuntu VPS.

bmitc2• 4 years ago

What are the issues?

For running directly on Windows you can simply run the Elixir installer, which will install Erlang and Elixir. After that, I highly recommend using the ElixirLS extension for Visual Studio Code. Note that on Windows, you need to use `iex.bat` and `mix.bat` instead of just `iex` and `mix` when running the commands. For example, `iex.bat -S mix.bat`. (I have it setup where I can leave off `.bat` for `mix`, but I can't remember what I did off the top of my head, if anything, to get that. `iex` conflicts with a PowerShell thing, so `iex.bat` is required.)

The other option is to install WSL2, install Erlang and Elixir there (I recommend using the asdf package manager (https://asdf-vm.com/). Once installed, use the Remote - SSH extension in Visual Studio Code on the Windows side to remote into the WSL2 instance. You could also download an official Elixir Docker container and again use Visual Studio Code (https://code.visualstudio.com/docs/devcontainers/containers).

OkayPhysicist2• 4 years ago

The iex.bat thing can be circumvented by dropping the iex alias for Invoke-Expression in your $PROFILE.

Joel_Mckay2• 4 years ago

Just put a Debian or Alpine install in a minimum disk image file, and mount a host machine path as a samba share from inside the VM (i.e. the user can edit the VM code without having to import/export constantly).

kvm/Hypervisor support on windows is patchy, but there are a lot of lower performance virtual machines that can work.

willmorrison• 4 years ago

What does your environment look like on NixOS? I had trouble connecting Phoenix to Postgres and ended up using SQLite for my test project. Do you have a database configured in shell.nix somehow?

mungobungo5• 4 years ago

Practical question here. How are Elixir/Erlang apps being deployed nowadays?

My understanding is that BEAM is designed for long running setups where hot reload of the code makes sense, and reboots are not happening that often thanks to the supervision trees.

But practically speaking how does it work under k8s env? When pod is being destroyed, what happens to all the messages sitting there? Pushing state out of actors is a possibility, but isn’t it ruin the whole idea of stateful actors ?

egze2• 4 years ago

Just to make it clear: you don't have to write stateful apps, just because you can. It's still possible to have the more traditional stateless model like Rails.

If you do write a stateful app, and run it in k8s, you can have state handover to a newly created pod. It works pretty well.

mungobungo5• 4 years ago

Well, let’s assume we are talking about a webshop. Every user is represented as an actor, a cart might be a state. So cart as a state should be stored somewhere else, let’s say redis. And every single read/write operation would be a network hop. What are the benefits of using actor model then ?

As for state handover between pods - what are the keywords to look for ?

rkangel2• 4 years ago

I think many modern applications aren't attempting the "long running, hot reload" model - they use a more conventional approach.

One thing that Elixir does well is handling faults - the relevant chunk of code 'crashes', and then restarts. The restart process does the appropriate recovery of any state. This turns all fault handling into a single code path (the startup path).

This approach also fits with the stateless style - the application should already be designed to start up properly and set up its state from scratch. Yes, in practice you design your application differently for a stateless deploy model, but Elixir helps you a lot in this model just as it does in the other one.

Joel_Mckay2• 4 years ago

Very nice, the world needs more people to write in Elixir/Erlang, and escape the polyglot hell the cloud shift incentivized.

markm208• 4 years ago

I am the author of the tutorial. I created a tool that captures keystrokes and file operations in a popular editor and allows them to be played back in a browser. The author can then add a narrative as the code evolves with text, pictures, and videos.

I have more 'books' on C++, python, SQL, web dev, dart/flutter, clojure, ruby, and more:

https://markm208.github.io/

I use these for the programming-focused cs courses that I teach instead of having the students buy bloated textbooks. The students prefer them to books (no surprise) and videos (somewhat surprising). The code is searchable and copy/pasteable so the students actually use it.

The tool is free and open.

pjm331• 4 years ago

awesome work - will definitely be checking this out not surprised that this is more popular format than textbooks and videos

warpech• 4 years ago

I love it. It is an interesting twist on the literate programming idea.

Congratulations on designing and developing the system, as well as pouring such a high quality content to it.

I can see the code of a book on GitHub[1]. It seems that the data of a single chapter is crushed in a single JS object[2].

Is the chapter data manageable in some text format, or is it only through the GUI presented in the docs[3]?

[1] https://github.com/markm208/exbook.

[2] https://github.com/markm208/exbook/blob/master/chapter1/01/j...

[3] https://markm208.github.io/storyteller/index.html

dy• 4 years ago

This is such a cool tool - I worked in coding education and always loved tools that let you playback/annotate code.

Thanks for posting!

djaouen2• 4 years ago

I have been on again/off again with Elixir for the past ten years, and I can imagine that the upgrade path between Phoenix/LiveView versions would be a pain for orgs that adopted Elixir early. I am not sure how Rails handled breaking changes (as I was never a Rails dev), but I think the rate of change is somewhat problematic if one were to adopt Elixir (and Phoenix/LiveView) today. Hopefully, this will change over time. Edit: and especially with the release of LiveView 1.0.

josevalim8• 4 years ago

Elixir has been backwards compatible since v1.0, released more than 7 years ago. Phoenix has also been API stable for a similar period of time and Ecto for 4+ years.

LiveView has changed over time but that’s precisely why it is on a 0.x release cycle. Even then, we do our best to deprecate first whenever possible. But the goal is that established projects have been stable.

In any case, LiveView is nearing 1.0 now, which makes us comfortable enough to promote it as part of the default Phoenix experience.

djaouen2• 4 years ago

Thanks for the reply, José.

I think the bigger problem with Elixir is the smallness of its community. There were several libraries that I started using (for example, Gringotts) that were actively developed for a while but then died off and nobody picked up where things were left off. Unfortunately, I am not skilled enough to put forth contributions myself (aside from the occasional bug report). But once LiveView hits 1.0, I think that if the community continues to expand, Elixir has an even brighter future.

Thanks for all your hard work making it possible! :)

lock-the-spock• 4 years ago

Very nice tutorial. But what I'm missing here and for many other similar ones isthe "why" question. Great that it is a functional language with immutability but what can I do with it? Please give me some example of what it does, how I can use it, how within a few minutes I can create something that works and is useful, ... Is it for web programming or a service or a backend or ...

Don't tell me I'll love it because of some programming feature. Make me see why I would love it by showing me how cool it is !

djfobbz• 4 years ago

Does anyone have detailed instructions on how to get Erlang Observer up and running on WSL/Win10? This has been my biggest gripe since I started learning Elixir. I love everything about it expect why isn't there a web-based observer for folks not using MacOS? Having to install all this JVM stuff to make it work gives me a severe headache. I've already looked on Google and didn't find anything with the level of detail that I was looking for. Someone please help!

An animated introduction to Elixir

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