Debugging in Clojure? [closed]

Answer 1

You can also insert code to drop yourself into a REPL with all the local bindings, using Alex Osborne's debug-repl:

(defmacro local-bindings
  "Produces a map of the names of local bindings to their values."
  []
  (let [symbols (map key @clojure.lang.Compiler/LOCAL_ENV)]
    (zipmap (map (fn [sym] `(quote ~sym)) symbols) symbols)))

(declare *locals*)
(defn eval-with-locals
  "Evals a form with given locals. The locals should be a map of symbols to
values."
  [locals form]
  (binding [*locals* locals]
    (eval
     `(let ~(vec (mapcat #(list % `(*locals* '~%)) (keys locals)))
        ~form))))

(defmacro debug-repl
  "Starts a REPL with the local bindings available."
  []
  `(clojure.main/repl
    :prompt #(print "dr => ")
    :eval (partial eval-with-locals (local-bindings))))

Then to use it, insert it wherever you want the repl to start:

(defn my-function [a b c]
  (let [d (some-calc)]
    (debug-repl)))

I stick this in my user.clj so it's available in all REPL sessions.