Is Elixir and it's ecosystem suitable for general purpose use as a Go replacement?

Scripting and REST APIs are no problem. Also CLI apps are possible (escript). But the target system needs to have Elixir installed. But I don’t think that is such a big problem. People these days don’t hesitate to install ruby just to use Jekyll.

Not really. Go, C, Rust, and even Python are much better for that for simple reason - you do not need whole VM to run such tool (and Python is commonly available OotB on many platforms). Additionally startup times in BEAM aren’t great, which mean that for short-living CLI tools it makes little sense, as startup is often main reason for “slowness” of such tools.

Again, not really, again, because of the slow startup.

If these tasks will be ran as a long running processes, then probably yes. There are tools for Elixir that make writing such applications much simpler and easier than in some other languages.

Everywhere where you will need long-running and IO-heavy workload that can be split into set small, independent, and isolated set of tasks (and REST API is perfect example of that) then Erlang/Elixir will be great choice.

Most of these are there because a lot of people are coming to Elixir from languages like Ruby or Python and are comparing it to the Go or Rust deployment cycle, where you either just dump sources on the server or you build one executable and dump that. However it is more like building C# assemblies (which are like Erlang applications) and deploying them to the Java Application Servers. For me it isn’t hard, you just need to understand that it is done in a slightly different way than you get used to. Erlang releases are more like Docker containers rather than Ruby on Rails deployments.

Erlang do not really have “executables”. The nearest what we can get are escripts, but these are more like JARs, where you have all code needed for the application to be ran, but you still need VM to run it.

Or whole web browser to edit text. I call these people “problem” as they are the reason for software bloat in recent years.

As someone who builds CLI apps with Elixir, I cannot confirm a slow startup time. Maybe it’s noticeable if you execute them a thousand times after one another, but if it’s meant to be executed from a person, I don’t see a problem here.

If this is application ran once then this is not much of a problem, but a lot of CLI tools is designed to work in batch workloads and is often ran a lot of times (for example find’s -exec flag). Of course it is possible to write CLI tools in Elixir, I am just saying that in a lot of workloads that CLI is used for it isn’t the best choice, as Elixir is focused more on client-server applications rather than batch processing.

Compared to a CLI app built in C, Rust, Go, etc it’s a lot slower since it has to boot the whole VM before starting. On my machine a “Hello World” escript takes about 0.5s.

So totally agree, if you are executing the script repeatedly in a hot path then it’s no good but if executed by a person that can be fine. For me it comes down to developer productivity, maintainability, familiarity, and ability to leverage the ecosystem (Ecto for example). Typically I can get non-trivial CLIs written much faster in Elixir.

I built my own static site generator using Elixir. I also often build little tools to convert files from one format into another, etc.

I once wrote a Golang CLI app that took a JSON file as input and generated a bunch of other files. Half a year later I discovered a bug (because the JSON file structure changed (thanks Postman team)) and was not able to fix it. Following the dataflow was impossible.

I too, and I often do not need anything more than AWK, sed, and shell. I understand that for some people Elixir can be easier, but at the same time this language wasn’t designed for it. This koan is about Vim, but I think it fits there as well:

One night there was a storm, and Master Wq’s house collapsed. The next morning he began to build it again using his old tools. His novice came to help him, and they built for a while and were making good progress. As they worked, the novice began to tell Master Wq of his latest accomplishments.

“Master, I have developed a wonderful Vim script to give all sorts of useful information about a document. It counts the words, the sentences, the paragraphs, and even tells you what kind of document it is using the syntax highlighting rules. I use it in my pipelines all the time. It is a thing of beauty, and I am very proud. Truly, Vim is the greatest tool!”

Master Wq did not reply. Thinking he had unwittingly angered his master, the novice fell silent and continued his work.

The novice finished aligning two beams and had positioned a nail ready for beating into the wood, but found the hammer was out of reach.

“Would you pass me the hammer, master?”

Master Wq handed the novice a saw.

At once, the novice was enlightened.

This marks few things:

• Go is a bad language, and I do not like it (in nice words)
• NIH is a problem, there is jq which probably would allow you to achieve the same thing with greater ease
• Unbounded mutability is bad as this makes following data flow at least hard

I use elixir for scripting extensively, both within a project and stand alone. The vm bootstrap is incidental for any case except the find -exec case mentioned above.

I’m giving a talk on Tuesday about this. I’ve also written a module that makes scripting much easier, handling arguments, dispatch and help in a simple and compact way. It’s a work in progress and will follow up here on its availability if there’s interest.

My recent use case was to load huge JSON logfiles, iterate over each line, parse the JSON, do something with the data (removing data, generating hashes, etc.) and writing to a new file. I guess it can be done with a combination of other tools, but i am not sure how maintainable and expressive it would be. Seeing the input format of some of these magic linux tools, I am starting to shake.

The goal was to convert a Postman collection structure to API Blueprint documentation. I don’t think jq would do that. If I knew Elixir back then, it would have been so much easier to accomplish. Also, EEx is much better than the retarded Golang template engine.

Interesting. For my static site generator, I very much copied most of the Mix CLI logic.

Release announcement of my scripting module:
scripting release announcement