Useful Clojure Macros

functions

(defn assoc-conj
  "Conjoin a value onto the list corresponding to the key `k` in `mp`."
  [mp k v]
  (if (empty? mp)
    {k [v]}
    (if (empty? (mp k))
      (assoc mp [v])
      (assoc mp
             (conj (mp k)
                   v)))))

macros.clj

(defmacro prefer [thing other]                                                     
  `(let [x# ~thing]                                                                
        (if x# x# ~other)))

(defmacro accept [form computation]                                                
  `(let [x# ~computation]                                                          
     (match x#                                                                     
           ~form x#                                                               
            :else nil)))

(defmacro debug [form]                                                             
  `(let [x# ~form]                                                                 
     (println                                                                      
       (str                                                                        
         "Debug: "                                                                 
         (quote ~form)                                                             
         " is "                                                                    
         x#))                                                                      
     x#))