Pretty-print methods of a Java class in Clojure. Useful inside the REPL.

README.md

The function print-methods is intended to be used inside a REPL. Just copy and paste it to your REPL and enjoy:

main=> ; paste print-methods
main=> (print-methods 1)
class java.lang.Long
-----------
bitCount(long) -> int
byteValue() -> byte
compare(long, long) -> int
;...

print_methods.clj

(defn print-methods
  "For a class 'x', print the methods (ordered by their name) in
   the following fashion:
   
   <methodName>(<parameters if any>) -> <return value>"
  [x]
  (let [meth-seq    (-> x class .getMethods seq)
        ordered-seq (sort-by #(.getName %) meth-seq)
        params      (fn [m] 
                      (let [ptypes (.getParameterTypes m)]
                        (if (= 0 (count ptypes))
                          ""
                          (clojure.string/join ", "
                            (for [x ptypes]
                              (.getName x))))))]
    (printf "class %s\n-----------\n" (-> x class .getName))
    (doseq [m ordered-seq]
      (printf "%s(%s) -> %s\n" (.getName m) (params m) (.getReturnType m)))))

clojure.print/print-table works too.

(use 'clojure.pprint)
(defn print-methods-2 [c]
  (->> (reflect c) 
       :members 
       (filter :return-type)
       (sort-by :name)
       (map #(select-keys % [:name :parameter-types :return-type])) 
       (print-table)))

|                 :name |                  :parameter-types |         :return-type |
|-----------------------+-----------------------------------+----------------------|
|              bitCount |                            [long] |                  int |
|             byteValue |                                [] |                 byte |
|               compare |                       [long long] |                  int |
|             compareTo |                [java.lang.Object] |                  int |
|             compareTo |                  [java.lang.Long] |                  int |
|       compareUnsigned |                       [long long] |                  int |
|                decode |                [java.lang.String] |       java.lang.Long |