clojure - eval code in different namespace

Question

I\'m coding something like REPL Server. Request from users evaluates in such function:

(defn execute [request]
  (str (try
          (eval (read-string request))         


        

Answer 1

Changing namespace means that you will have to reinitialize all the aliases, or refer to even clojure.core stuff with a fully qualified name:

user=> (defn alien-eval [ns str]
         (let [cur *ns*]
           (try ; needed to prevent failures in the eval code from skipping ns rollback
             (in-ns ns)   
             (eval (read-string str))
             (finally 
               (in-ns (ns-name cur))
               (remove-ns ns))))) ; cleanup, skip if you reuse the alien ns
#'user/alien-eval
user=> (alien-eval 'alien "(clojure.core/println clojure.core/*ns*)") ; note the FQN
# ; the effect of println
nil                ; the return value of alien-eval