gistfile1.el

(defun my-send-to-nrepl ()
  (interactive)
  (let ((p (point)))
    (cider-eval-last-sexp 't)
    (goto-char p)
    (insert " ;;=> ")))

(defun my-send-to-nrepl2 ()
  (interactive)
  (let ((p (point)))
    (cider-eval-last-sexp 't)
    (goto-char p)
    (insert "\n;;=> ")))

(defun my-send-to-nrepl3 ()
  (interactive)
  (let* ((s (cider-last-sexp))
	 (data (cider-eval-sync s))
	 (v (plist-get data :value))
	 (e (plist-get data :stderr)))
    (popup-tip (format "%s" (or e v)) :truncate 't)))