Combinators are an important part of functional programming. They are functions — usually small — that combine their arguments into new functions. They’re great fun and have a lot to teach about functional programming and the lambda calculus. They are an important part of any Clojure programmer’s toolkit.
Screencasts, Whiteboards, and Slides produced to help you learn
Learn the fundamentals of core.async, a concurrency library for Clojure and ClojureScript that gives you tremendous power.
You want to learn Clojure but it seems so daunting. Who has the time to read and read and then start yet another half-finished project? Clojure in One Hour is a series of short projects that you can do in one hour. No theory, just hands-on projects to get something done.
Protocols are a very cool and very important feature in Clojure. They are a great way to build polymorphism into your software, including extending existing Java classes without modifying them.
When you are looking at a variable, how do you know what it refers to? The rules that determine what variable names refer to are collectively called the scoping rules. Learning the three kinds of scope and when to use each will help you make your code more maintainable.
Learn the tricky corners of Clojure syntax, like for comprehensions and function definitions.
Pragmatic and in-depth guides to a topic.
Reagent is a ClojureScript wrapper around React. It makes it easy to create React components using functions and hiccup, and state managed in Atoms.
So you want to know who’s using Haskell and where to find jobs? You’ve come to the right place.
Easy to follow installation guides for the three main platforms: macOS, Linux, and Windows. This guide shows you how to install everything you need: Java, Leiningen, and the Clojure CLI tool.
Josh Doody (Salary Negotiator) and Eric Normand critique a functional programming résumé and give advice for making it better. They also talk about preparing for the interview and the salary talk.
Learn the 4 React Lifecycle Methods you’ll need to know for Reagent/Re-frame and why the other 6 are not needed.
Is functional programming a fad? We cut through the buzz cycle and answer the question once and for all.
Small, precise guides to a particular feature.
Clojure has been successfully adopted by many companies. There are many resources available by people who did the hard work of introducing Clojure to their team.
If your functions return `core.async` channels instead of taking callbacks, you encourage them to be used within `go` blocks. Unchecked, this encouragement could proliferate your use of `go` blocks unnecessarily. There are some coding conventions that can minimize this problem.
There are two commonly used ways to create new data types in Clojure, deftype and defrecord. They are similar but are intended to be used in two distinct use cases. deftype is for programming constructs and defrecord is for domain constructs.
Unit testing in Clojure is straightforward. Here are a few testing ideas as they apply to Clojure.
Hiccup is a Clojure DSL for generating HTML. If you’re using it, you might like these tips.
Although it’s still early, ClojureScript is rapidly maturing its testing story. There are a Leiningen plugin and a Boot task for autocompiling ClojureScript as it changes and running tests in a variety of engines.
Use the OWASP Top Ten Project to minimize security vulnerabilities in your Clojure web application.
Clojure was designed as a hosted language. So what is Clojure, the language, if it relies on the features of a host? And what are the disadvantages of choosing the JVM as a host?
People know about the immutable data structures and the STM. But there’s something going on at a much deeper level that is really hard to get right in Java. It has to do with the optimizations the JIT will run on your code.
Conveyor belts are strikingly similar to Clojure core.async channels. While it could be a coincidence, there is speculation that conveyor belts were influenced by a deep understanding of core.async.
It’s common that adding more layers of abstraction or indirection will make things slower. However, React and ClojureScript make web pages faster than doing it by hand — essentially programming the bare web. The lesson is that if you choose your layers well, they can actually make your system faster.
Parts of courses on specific topics
Sometimes we need to get a reference to the real DOM node that React normally manages for us. For instance, when we need to play an embedded video, the API requires access to the DOM node of the video element. React gives us a feature called Refs that let us get access to any DOM node it creates.
You know those HTML components that show you some headers and let you expand the content underneath? Yeah! Let’s build one!
Let’s add a new ingredient, namely cocoa.
Now that we can bake recipes, let’s add the other recipes, cookies and brownies.
Let’s add an action for adding ingredients.
We modify the compiler to add static scope information. Even though we don’t know the value of variables until runtime, we do know the names of the variables at compile time. We can use that to make missing variables a compiler error.
PDFs, code, and other downloads to help you learn
Guide to baking for the intrepid robot
How to install: Download the CSV file (click the thumbnail below). Install Anki. Run Anki. Click Import at the bottom of the window. Import the CSV file. Adjust the options like you see them below.
A printable PDF (double-sided) with the 100 most common Clojure expressions. One side has the function/macro, the other a quick explanation. This is for printing on Avery 5371 paper.
A printable PDF (double-sided) with the 100 most common Clojure expressions. One side has the function/macro, the other a quick explanation. This one has a grid for cutting by hand.
Events, Effects, Co-effects, and Subscriptions! This reference sheet shows you the most common forms of all of these so you can get started with Re-frame right away.
Learn the four important React Lifecycle methods you’ll need when using Re-frame, when to use them, and how. Get started with Re-frame right away.
We Interviewed Allison McMillan about her upcoming Curry On 2017 talk called Angelina Ballerina Learns About Memory Allocation.
We interviewed Alvaro Videla about his upcoming clojuTRE 2017 talk called Metaphors We Compute By.
We interviewed Anatoly Polinsky about his upcoming Clojure Remote 2017 talk about configuration.
We interviewed Andrew Mcveigh about his upcoming :clojureD 2017 talk.
We interviewed Annette Bieniusa about her upcoming Lambda Days 2017 talk.
We interviewed António Monteiro about his upcoming ClojuTRE 2017 talk called Lumo: Bootstrapping a Standalone ClojureScript Environment.
Issue 338 – August 05, 2019 · Archives · Subscribe Clojure Tip 💡 Re-implement your code multiple times One of the best ways to get good at the idiom-level coding is to re-implement the same function multiple times. Implement it once, and get it working. Then have fun and try to implement it a different […]
Issue 337 – July 29, 2019 · Archives · Subscribe Idea 💡 Functional programming is deep I was once coaching an experience procedural and OO programmer in FP. We were writing a Solitaire game. At some point, after we had modeled the cards and game board, I suggested we generate every possible move, then filter […]
Issue 336 – July 22, 2019 · Archives · Subscribe Book status 📖 Word from Manning is that the book will be available in early access next week. It’s not for sure, but I’m crossing my fingers. 🤞 As you may know, I’m writing a book called Taming Complex Software, which is an introduction to […]
Issue 335 – July 15, 2019 · Archives · Subscribe Idea 💡 When can you use Property-Based Testing? I’m working on a course on Property-Based Testing, and I’d like to compare it to example-based testing. My understanding of example-based testing is that people recommend you test before you write code. The reason you test before […]
Issue 334 – July 08, 2019 · Archives · Subscribe Clojure Tip 💡 can you fill in the blanks? One of the cooler experiences of functional programming is when you start to see the arguments of functions as “blanks”. That is, they are blanks that you have to fill in to get a successful function […]
Issue 333 – July 01, 2019 · Archives · Subscribe Clojure Tool 🔨 rebel readline Bruce Hauman’s terminal repl is really slick. I like to think of it as 80% of the stuff you get from an IDE without having to get repl integration working. It’s got syntax highlighting, paren matching, really nice history, and […]