Use restart mechanism to let user select from options.

selection-restart.lisp

(define-condition selection-required (simple-error)
  ((message :initarg :message :reader message))
  (:report (lambda (c s) (format s "Selection required: ~A" (message c)))))

(defmacro selection-restarts (options message)
  "Generates restart-case from given list of options. Useful for interactive selection."
  (let ((x    (gensym))
        (rpt  (gensym))
        (i    (gensym))
        (name (gensym)))
    `(eval
      `(restart-case
           (error 'selection-required :message ,,message)
         ,@(loop for ,x in ,options
                 for ,rpt = (format nil "~A" ,x)
                 for ,i from 0
                 for ,name = (intern (format nil "option-~A" ,i))
                 collect `(,,name () :report ,,rpt
                                 (quote ,,x)))))))

;;Usage
(selection-restarts (mapcar #'identity (loop for x from 0 to 5 collect (* x 3)))
                    "Choose which one?")

sldb-output.txt

Selection required: Please choose which value to use:
   [Condition of type SELECTION-REQUIRED]

Restarts:
 0: [option-0] 0
 1: [option-1] 3
 2: [option-2] 6
 3: [option-3] 9
 4: [option-4] 12
 5: [option-5] 15
 6: [RETRY] Retry SLIME REPL evaluation request.
 7: [*ABORT] Return to SLIME's top level.
 8: [ABORT] abort thread (#<THREAD "repl-thread" RUNNING {10045D8453}>)