Proof of concept for REPL sessions with scoped context

scoped_repl.clj

(def ^:dynamic *depth* 0)

(defn repl-env [env]
  (with-local-vars [ret nil]
    (clojure.main/repl
      :eval #(var-set ret (eval `(let [~@(mapcat identity env)] ~%)))
      :prompt #(printf "%s%s=> " (ns-name *ns*) (apply str (repeat *depth* "="))))
    @ret))

(defmacro cnt []
  `(let [~'locals ~(->> &env keys (map (fn [n] [`(quote ~n) n])) (into {}))]
     (binding [*depth* (inc *depth*)]
       (repl-env ~'locals))))

; user=> (let [a 1] (cnt))
; user==> (inc a)
; 2
; user==> Ctrl+D
; 2
; user=> a
; user=> Unable to resolve symbol: a in this context