dave yarwood
Minutiae #1: Alda stuff, Clojure tooling for Vim


July 28, 2019


I’ve been meaning to update this blog more often for a long time now. The problem I have is that I have a lot of interesting things that I could write about, but I feel like it would take so much effort to produce a blog post worth reading, I just never have the time to do it. As a result, I’ve been setting aside time only about once every 2 to 6 months to write a long blog post about a particular topic.

I’ve been thinking lately that it might be interesting to explore writing smaller, more frequent posts about various things I’ve been spending time on or that have captured my interest lately. Alex Miller and Bozhidar Batsov have been doing this sort of journaling recently and I really enjoy reading it, so I figured I’d take a stab at it too.

Here we go!

Strange Loop

I’m thrilled to be speaking at Strange Loop in September! I’ll be talking about a handful of interesting directions that I’ve taken Alda over the last 7 years, and in particular, Alda’s evolving relationship with Clojure.

Alda 2

Since December, I’ve been gradually rewriting Alda from the ground up. It’s a huge undertaking, but something I’ve been wanting to do for a very long time. I’ll be talking about this in more depth in my talk at Strange Loop, but just as a teaser, the next version of Alda will feature:

  • A simpler architecture that does more work on the client side.
  • A native executable client written in Go.
  • Support for live coding.

If you’re interested in following my progress, you can watch the Alda 2 project on GitHub or say hello in the #development channel in the Alda Slack group.


I recently hacked together something interesting to help someone build a game for a competition. I call it alda4j.

Alda4j is for the niche use case where you want to embed Alda into your Java application. It leverages the Clojure Java API to invoke the Clojure code being run on the Alda background worker process, but in the foreground in your application.

Here is some example Java code that uses Alda4j to play lines of Alda code that are input by the user.

Vim Clojure tooling and the prepl

It’s always been interesting to be a Vim user in the Clojure community. By and large, Clojure programmers tend to use either Emacs or Cursive. The 2019 State of Clojure survey results show 46% of respondents using Emacs, 30% using Cursive, and a scant 10% using Vim as a primary Clojure development environment.


Fireplace has been the standard Vim plugin for Clojure development for quite a long time, and it’s still the one that I would recommend to people who are just getting started with using Vim tooling for Clojure. The main reasons that I would recommend it are that it’s been around for the longest, and it’s the one that I would guess most Clojurist Vimmers use today, so if you run into any problems, chances are you’ll be able to find someone who can help.

I’ve never had any major problems with Fireplace, but I’ve noticed more and more Vim plugins doing their work asynchronously, which is super awesome because it makes the overall Vim experience feel fast and lightweight. As of the last time I used Fireplace, it was handling code evaluation synchronously, meaning that every time I evaluated a Clojure expression, I would have to wait however many milliseconds it took for the result to come back before I could do anything else in Vim. That might not sound terrible, but when you live in your text editor like I do, being able to speed up things like this is a major quality-of-life improvement!

Acid, vim-iced

Not long ago, I started seeing alternative Clojure plugins for Vim begin to spring up, some of which advertised that they were doing things asynchronously, which piqued my interest. Two plugins worth exploring in this arena are acid and vim-iced. Both acid and vim-iced operate by communicating with an nREPL server that you start within the context of your project.


More recently, there is a new plugin called Conjure that provides Clojure tooling by using a prepl connection instead of an nREPL connection. The prepl itself is a new tool that has only been a part of Clojure since version 1.10, which was released in December 2018. The prepl is conceptually simpler than the nREPL, and it is designed for programmatic use by things like editor plugins. Conjure provides a really excellent development experience out of the box, and it’s obvious that a lot of thought has gone into the user experience, which I appreciate. I’ve had a handful of conversations with the author and he’s been very responsive and considerate. The plugin continues to improve week by week and it’s a joy to use.

No comment

You may have noticed that I’ve quietly removed the comments section of this blog. For the most part, my blog posts don’t really get any comments via the Disqus widget. If people comment on or discuss my writing at all, it mostly tends to happen on Reddit and Hacker News, where I’m in the habit of posting my lengthier blog posts.

I probably won’t post smaller posts like this one on Reddit and Hacker News, but I will at least mention them on Twitter, and hopefully I’ll remember to post a link to the Twitter thread on the blog post for comments. If I forget to do that, you can always just tweet in my general direction!


Reply to this tweet with any comments, questions, etc.!