When I started learning/using Clojure, I didn't use the REPL much and kept on working in the traditional way: Write code, compile, test. Repeat until it works.

When I started learning/using Clojure, I didn't use the REPL much and kept on working in the traditional way: Write code, compile, test. Repeat until it works. It took some time to break my old habits and start using the REPL. It's unfortunately made me a bit lazier writing unit tests :), as I can hammer on a piece of code until I know it works - and small, deterministic functions tend to not break once you get them working. So much of my test code is integration tests. Nowadays, when I have to work in Java (or Scala, Javascript, Python, etc), I seriously miss the Clojure REPL. Though Clojure (and Lisp in general) has definitely affected the way I write code in other languages.