The Joy of Clojure, Second Edition

Chapter 15. Performance

This chapter covers

• Type hints
• Transients
• Chunked sequences
• Memoization
• Understanding coercion
• Reducibles

Now that you’ve spent a book’s worth of material learning the why and how of Clojure, it’s high time we turned our attention to the subject of performance. There’s a meme in programming that can be summarized as follows: make it work first, and then make it fast. Throughout this book, we’ve taught you the ways Clojure allows you to “make it work,” and now we’re going to tell you how to “make it fast.”

In many cases, Clojure’s compiler can highly optimize idiomatic Clojure source code. But there are times when the form of your functions, especially in interoperability scenarios, will prove to be ambiguous ...