Common Pitfalls with Macros

The most common macro bugs are not “syntax bugs.” They are semantic bugs: the macro expansion evaluates something more times than you intended, or it introduces names that collide with the caller’s code.

Watch for:

• Multiple evaluation: if you splice an expression into two places, it runs twice.
• Variable capture: accidentally shadowing or referencing a symbol from the caller’s scope.
• Unreadable expansions: the generated code is harder to understand than the original boilerplate.

If you cannot explain the expansion clearly, it is usually a sign the macro is too big.

In this section

• Understanding Macro Expansion and Evaluation Order in Clojure
  Explore the intricacies of macro expansion and evaluation order in Clojure, focusing on common pitfalls and best practices for Java developers transitioning to Clojure.
• Understanding Variable Capture and Hygiene in Clojure Macros
  Explore the intricacies of variable capture and hygiene in Clojure macros, with examples and solutions for Java developers transitioning to Clojure.
• Debugging Macros in Clojure: Strategies and Techniques
  Explore effective strategies for debugging Clojure macros, including using macroexpand, breaking down complex macros, and testing with diverse inputs. Enhance your understanding of macro debugging with practical examples and comparisons to Java.