(defmacro hello [x] (str "Hello, " x)) (defmacro infix [form] (list (second form) (first form) (nth form 2))) (defmacro infix-better [form] `(~(second form) __ __ )) (defmacro r-infix [form] (cond (not (seq? form)) form (= 1 (count form)) `(r-infix ~(first form)) :else (let [operator (second form) first-arg (first form) others (drop 2 form)] `(~operator (r-infix ~first-arg) (r-infix ~others))))) (meditations "Macros are like functions created at compile time" (= __ (hello "Macros!")) "Can I haz some infix?" (= __ (infix (9 + 1))) "Remember, these are nothing but code transformations" (= __ (macroexpand '(infix (9 + 1)))) "You can do better than that, hand crafting ftw!" (= __ (macroexpand '(infix-better (10 * 2)))) "Things dont always work as you would like them to... " (= __ (macroexpand '(infix-better ( 10 + (2 * 3))))) "Really, you dont understand recursion until you understand recursion" (= __ (r-infix (10 + (2 * 3) + (4 * 5)))))