More blog posts.
It’s easy to forget the Java Development Kit is, in fact, a kit. Many Clojure developers, myself included, rarely work with commands like java directly, instead using lein , boot , or clojure . Often we don’t even use the Java standard library directly in favor of idiomatic wrappers.
There are a lot of advantages to staying in the Clojure level. Often, Clojure-specific tools ergonomically support common practices like live-reloading, understand Clojure data structures, and can tuck away some of the intermediate layers of Clojure itself that aren’t a part of your application.
Lambda Island Open Source Update January 2022.
Community contributors and Lambda Island team members have been busy working on new projects and improving existing ones.
If you want to join in, check out our blog post calling for contributions, or jump right in to our first issues list.
Making nREPL and CIDER More Dynamic (part 2)
By Arne Brasseur.
In part 1 I set the stage with a summary of what nREPL is and how it works, how editor-specific tooling like CIDER for Emacs extends nREPL through middleware, and how that can cause issues and pose challenges for users. Today we’ll finally get to the "dynamic" part, and how it can help solve some of these issues.
To sum up again what we are dealing with: depending on the particulars of the nREPL client (i.e. the specific editor you are using, or the presence of specific tooling like refactor-clj ), or of the project (shadow-cljs vs vanilla cljs), certain nREPL middleware needs to present for things to function as they should. When starting the nREPL server you typically supply it with a list of middlewares to use. This is what plug-and-play "jack-in" commands do behind the scenes. For nREPL to be able to load and use those middlewares they need to be present on the classpath, in other words, they need to be declared as dependencies. This is the second part that jack-in takes care of.
Making nREPL and CIDER More Dynamic (part 1)
This first part is a recap about nREPL, nREPL middleware, and some of the issues and challenges they pose. We’ll break up the problem and look at solutions in part 2.
The REPL is a Clojurists quintessential tool, it’s what we use to do Interactive Development, the hallmark of the LISP style of development.
In Interactive Development (more commonly but somewhat imprecisely referred to as REPL-driven development), the programmer’s editor has a direct connection with the running application process. This allows evaluating pieces of code in the context of a running program, directly from where the code is written (and so not in some separate "REPL place"), inspecting and manipulating the innards of the process. This is helped along by the dynamic nature of Clojure in which any var can be redefined at any point, allowing for quick incremental and iterative experimentation and development.
The Obstacles of Effective Debugging.
by Laurence Chen.
Have you ever had one of the following experiences before?
The Classpath is a Lie.
by Arne Brasseur.
A key concept when working with Clojure is "the classpath", a concept which we inherit from Clojure’s host language Java. It’s a sequence of paths that Clojure (or Java) checks when looking for a Clojure source file ( .clj ), a Java Class file ( .class ), or other resources. So it’s a lookup path, conceptually similar to the PATH in your shell, or the "library path" in other dynamic languages.
The classpath gets set when starting the JVM by using the -cp (or -classpath ) command line flag.
A Tale of Three Clojures.
Recently, I was helping a coworker debug an issue with loading a Clojure dependency from a Git repository. (If you don’t know you can do this; it’s very handy. Here’s a guide.) I realized that there were really two Clojures at play: the Clojure that clojure was running to generate the classpath and the Clojure that was used by the actual Clojure program.
Taking a step back, there are really three things we might mean when we say "Clojure":
Launching the Lambda Island Redesign.
It’s finally live! A gorgeous, in-depth redesign of the Lambda Island website. After months of hard work we soft-launched earlier this week. Today we want to tell you a little more about the project, the whys and the hows, and to invite you to check it out. And when you’re done do come tell us what you think on our Discord.
We already told you in a previous post how Lambda Island and Gaiwan are changing. In a short amount of time we went from a one man endeavor to a team of six, drastically changing what we are able to take on and pull off.
Lambda Island Open Source Update July 2021.
It’s been a while since our last update! Community contributors and Lambda Island team members have been busy working on new projects and improving existing ones. We’re trying to strike a balance between venturing into new territory while ensuring existing projects continue to improve.
If you want to join in, check out our blog post calling for contributions, or jump right in to our first issues list.
Lambda Island is Changing.
Last month marked the five year anniversary of Lambda Island. Five years since I quit my job, built a video platform, and figured out how to put together tutorial videos. It’s been quite a ride. All this time I’ve been fortunate to be part of the Clojure community, to watch it grow and evolve, and to help individuals and companies to navigate these waters.
I learned some hard lessons along the way. Like how hard it is to bootstrap an educational content business catering to a niche audience, or how lonely and stressful it can be in business to go it alone.
And with these lessons came changes. I started doing more consulting work again. To some extent it was a necessity, but it also provided me with an opportunity to get involved with many Clojure projects out there in the wild. To work with talented individuals, to learn what amazing things people were doing, and to help shape these companies, products, and the greater narrative around Clojure as a technology and binary options community.
Why are Clojure beginners just like vegans searching for good cheese?
Have you ever wondered what to do if you love cheese but you want to be a vegan and how this affects you when you learn Clojure?
This was my question too. I love cheese, but I wanted to find a good vegan cheese replacement for my breakfast sandwich. This wasn’t a fun journey, all the vegan cheese substitutes weren’t like the real deal! After a talk with one of my vegan friends, he told me that my point of view over cheese replacement in the sandwich was wrong. Instead of searching for a good and tasty vegan cheese replacement, just replace it with an avocado. Avocado is a good replacement for your morning sandwich without the compromising that you would do with tasteless vegan cheese substitutes.
The beginner's way.
An OOP developer finding her way in the functional world, what could go wrong?
So why Clojure?
Call for Contributions to Lambda Island Open Source.
We’re always excited when someone new contributes a fix, test, documentation update, or even a major new feature to our open source projects. If you’re new to programming, open source projects are a great way to get experience working on a larger project. If you’re not so new, they can be an opportunity to try a new technology or work on a kind of software you usually don’t get a chance to. Either way, it’s rewarding to help out your fellow users or developers—these issues are for Kaocha, one of the most popular and advanced Clojure test runners.
But open source can also be intimidating. If you haven’t been sure where to start, then this post is for you! We’ve outlined the process step by step, and we’re here to support you every step of the way.
Logging in Practice with Gl_gi and Pedestal.log.
In an earlier post I tried to map out the Clojure/Java logging landscape a bit, so people can make an informed choice about how to set up logging for their application. There are several solutions out there with different trade-offs, and recently both Timbre and mulog have had some new releases. However until further notice the default logging setup in the "Lambda Island Stack" remains pedestal.log on the backend, and binary options Gl_gi at the front.
This blog post is a bit of practical advice on how to make good use of logging, with the focus on these two libraries, which both provide the same API, just for a different platform.
This API consists of a number of macros corresponding with the different log levels, which all take key-value pairs as arguments.
Well Behaved Command Line Tools.
Yesterday Vlaaad wrote a pretty cool blog post titled Alternative to tools.cli in 10 lines of code. It’s a great read and a very cool hack. It uses read-string to parse command line arguments, resolves symbols, and invokes the first symbol/function, passing in the rest of the parsed arguments. In other words: it’s the most straightforward way to translate a command line invocation into a Clojure function call.
The benefits are illustrated well in the post. It removes all possible friction. Want to add a new subcommand? Just add a function. Adding CLI arguments and options equals adding arguments and options to said function.
It’s actually not too different from what people do in shell scripts sometimes.
Lambda Island Open Source Update May 2020.
Felipe and I have been busy again, read all about what we’ve been up to in this month’s Lambda Island Open Source update.
We currently have two major projects we are working to get out: Regal and Kaocha-cljs2. They are both still a work in progress, but we’ve again made some good progress this month. Regal is not officially out yet but is at the stage where people can safely start incorporating it into their projects. Kaocha-cljs2 is a big undertaking, but we’re splitting this work into smaller self-contained pieces, and two of those saw their first release this month: Chui and Funnel.
Regal.
Lambda Island Open Source Update April 2020.
With people across the globe isolating themselves it feels sometimes like time is standing still, but looking back it’s been a busy month again for the folks here at Lambda Island. Besides all the maintenance releases we shipped some new features for lambdaisland.uri, our JS logging library Gl_gi, and a new micro-library, edn-lines. We also have some exciting work in progress, including a brand new browser-based test runner for ClojureScript, written with shadow-cljs in mind.
Funding.
A big shout goes out to two of our clients, Nextjournal and Pitch. They have made a lot of this work possible either by funding projects directly, or by dogfooding our tools and libraries and giving us an opportunity to improve them. Thank you both for investing in this great ecosystem.
Coffee Grinders, part 2.
Back in December I wrote about a coding pattern that I’ve been using more and more often in my work, which I dubbed "Coffee Grinders". My thoughts around this were still gelling at the time, and so the result was a meandering semi-philosophical post that didn’t really get to the point, and that didn’t seem to resonate that much with people.
Some of the responses I got were "just use functions" or "sounds like a finite-state machine", which makes it clear that I was not in fact making myself clear.
Having continued to encounter and apply this pattern I’d like to present a more concise, semi-formal definition of coffee grinders.
Launching an Open Collective for Lambda Island OSS.
We are launching an Open Collective for Lambda Island Open Source, to help support our Open Source and Community work. Please check it out, pass it (and this article) on to your boss, or consider contributing yourself.
It started with a mission.
Advent 2019 part 24, The Last Post.
This post is part of Advent of Parens 2019, my attempt to publish one blog post a day during the 24 days of the advent.
Day 24, I made it! I did skip a day because I was sick and decided it was more important to rest up, but I’m pretty happy with how far I got.
Let’s see how the others fared who took on the challenge. John Stevenson at Practicalli got four posts out spread out across the advent period, similar to lighting an extra candle every sunday of the advent. Good job!
Advent 2019 part 23, Full size SVG with Reagent.
This post is part of Advent of Parens 2019, my attempt to publish one blog post a day during the 24 days of the advent.
I’ve been a big fan of SVG since the early 2000’s. To me it’s one of the great victories of web standards. Mind you, browser support has taken a long time to catch up. Back then you had to embed your SVG file with an