Ep 095: Composing Core

Functional Design in Clojure

Each week, we discuss a different topic about Clojure and functional programming.

If you have a question or topic you'd like us to discuss, tweet @clojuredesign, send an email to [email protected], or join the #clojuredesign-podcast channel on the Clojurians Slack.

This week, the topic is: "core and composition." We venture toward the core of a solution.

Our discussion includes:

• Why do functional programmers like to talk about composition?
• What composition means in object-oriented programming vs functional programming.
• Must simple be simplistic?
• What is idiomatic composition?
• Common kinds of functions.
• Why functional programming is more like Legos than taxonomies.
• What Clojure already knows and what you have to teach it.
• Why Clojure allows you to put things together quickly.
• Why side effects can ruin everything.
• How Clojure encourages composition.

Selected quotes:

• "I don't think you want me to read code to you. That sounds like an excellent way to fall asleep if you have insomnia!"
• "Maybe we need a white noise track of keyboard noise."
• "Composition in a functional language is much simpler because we just have functions."
• "Why have we spent so much time talking about composition when it's just functions calling other functions?"
• "These names are a little on the nose, but programmers aren't always the best at originality!"
• "Functional programming is essentially based on transformation. Everything is a transform at some point in time."
• "The only way to get anything done is to return a new thing."
• "Core is a backbone, a spine, and you're connecting a progression of things together."
• "Your job, as a functional developer, is to teach Clojure core about your domain."
• "They're all functions that remix very well."
• "Everything must be pure because side effects mess up this whole world."
• "Make functions small because functional programming makes it very easy to combine smaller functions into bigger functions. Build up your functionality from those pieces."

Links:

• Ep 075: Merge With Fun
• Ep 079: Compose Thyself
• Ep 093: Waffle Cakes
• Ep 094: Concrete Composition