Elixir and Rust is a good mix

I made the ‘risky’ decision to learn Elixir & Phoenix for a 6 week University project that I delivered earlier this week. It could have turned out to be a terrible decision but honestly once I got my head around it, it’s probably some of the most productive coding sessions I’ve ever had. Deploying to Fly.io was also amazing, I think it was 3-5 commands from signup to deployed with a database. Very happy with it all.

I used to use Elixir, but the lack of static types got to me (especially since I prefer the type-driven development methodology). Using Rust afterwards was great, plus it was faster than the BEAM. I guess, why not use Rust entirely instead of as a FFI into Elixir or other backend language? I've been using Axum and it works pretty well. The only time I had to do FFI with Rust was with Flutter via flutter_rust_bridge, for running a CRDT library (automerge) that was implemented in Rust, for offline app functionality.

I admit for a long time this was my primary motivation to learn Rust, but, sadly, I haven&#x27;t come across problems in years that were CPU bound&#x2F;where I needed something like Rust... Rustler still looks like a great fit if needed, but, depending on the use case, if I were CPU bound and needed to write my own code&#x2F;not just use a Rust library, I&#x27;d be as or more likely to look at using Zig and Zigler[0], for much faster learning curve, and from what I&#x27;ve read, easier tighter integration into elixir, including I think language server integration. Some discussion here[1] though I forget if I listened to this one or not.<p>[0]<a href="https:&#x2F;&#x2F;github.com&#x2F;ityonemo&#x2F;zigler">https:&#x2F;&#x2F;github.com&#x2F;ityonemo&#x2F;zigler</a> [1]<a href="https:&#x2F;&#x2F;podcast.thinkingelixir.com&#x2F;83" rel="nofollow">https:&#x2F;&#x2F;podcast.thinkingelixir.com&#x2F;83</a>

Author here. The rustler team has really made a great developer experience using Rust in Elixir and I just had to share.

Shameless plug &amp; also a point of support for the article: I used that same stack to build <a href="https:&#x2F;&#x2F;regex.help&#x2F;" rel="nofollow">https:&#x2F;&#x2F;regex.help&#x2F;</a> (more details here <a href="https:&#x2F;&#x2F;maciej.gryka.net&#x2F;building-regex-help" rel="nofollow">https:&#x2F;&#x2F;maciej.gryka.net&#x2F;building-regex-help</a>)

If you&#x27;re extending Elixir with Rust, familiarize yourself with precompiled rustler: <a href="https:&#x2F;&#x2F;dashbit.co&#x2F;blog&#x2F;rustler-precompiled" rel="nofollow">https:&#x2F;&#x2F;dashbit.co&#x2F;blog&#x2F;rustler-precompiled</a>

This is essentially what has gotten me into Rust. Knowing how easy Elixir makes it to offload a piece of my system that would benefit from it without needing to write the entire thing in Rust.

I used this in past, but there were a lot of people saying that NIFs&#x2F;ports are dangerous to use. Did any of this change or are there tried and tested practices that can be applied? What I used this for wasn&#x27;t critical app so I didn&#x27;t mind it going down.<p>IIRC one threat was Rust sharing memory with BEAM which could exhaust it and cause OOM crash?

This is amazing! The Gods have sent me the perfect excuse to finally read all the rust ebooks I’ve been collecting! I have a toy project where certain functions are CPU-bound and would make for a perfect learning project. Very timely read!

Elixir, rust and fly.io in the same post. HN bingo.

I remember MS reps coming to our offices in the 90s and &quot;Teaching&quot; us how to program and how it is cool to have one person writing GUI and the other &quot;guru&quot; writing high performance C++ to be used in critical parts.<p>I showed them a piece of software that was mighty fast, Internet enabled and GUI intensive. They liked the software but asked where did you get this particular screen control from. You&#x27;ve got to see their faces when told that the whole software was written by a single person in Delphi.

Doesn&#x27;t the use of Rust have to be extremely minimal because ErlangVM has hard time limits on their preemptive scheduler and if your Rust code hasn&#x27;t finished when preempted, that causes lots of problems.<p>EDIT: thanks for pointing out where in the article this is talked about.

This makes me think of DotCloud, the precursor to Docker Inc. The idea that you can run anything has been around for a while. I don&#x27;t see how Fly.io is especially good for Elixir. It seems to be about delivering reliable resources for each service, and it works no matter the web framework, as long as you have a PaaS that&#x27;s geared towards running arbitrary OCI images. These posts seem a lot like the content on the DigitalOcean site, except they&#x27;re written by staffers instead of freelancers. <a href="https:&#x2F;&#x2F;www.digitalocean.com&#x2F;community&#x2F;pages&#x2F;write-for-digitalocean" rel="nofollow">https:&#x2F;&#x2F;www.digitalocean.com&#x2F;community&#x2F;pages&#x2F;write-for-digit...</a>

IO in erlang is slow, is Rustler a good candidate to improve IO intensive applications?