Understanding Macro Expansion

Macros are easiest to understand when you stop guessing and start expanding.

At the REPL, two tools do most of the work:

• macroexpand-1 expands a form once (one macro step).
• macroexpand keeps expanding until the form is no longer a macro call.

1(macroexpand-1 '(when true (println "hi")))

As a Java developer, treat this like looking at generated source: you don’t trust the generator until you can read what it produces.

In this section

• Understanding Macro Expansion in Clojure: The Macro Expansion Process
  Explore the macro expansion process in Clojure, a powerful feature that allows for code transformation before evaluation, enhancing code flexibility and expressiveness.
• Clojure Macro Expansion: Using `macroexpand` and `macroexpand-1`
  Explore how to use `macroexpand` and `macroexpand-1` in Clojure to understand and debug macros, with examples and comparisons to Java.
• Visualizing Macro Transformations in Clojure
  Explore how to visualize macro transformations in Clojure, understand macro expansion, and ensure macros behave as intended.