slime-update-clojure-namespace.el

(require 'pc-select)
(defun slime-update-clojure-namespace () 
  "Find the namespace in the current buffer and use SLIME's REPL 
to switch to it, updating the namespace for all buffers." 
  (interactive) 
  (save-excursion
    ;; search for this buffer's namespace:
    (goto-char 0)
    (when (search-forward "(ns " nil t)
      (let ((beg (point))
            (end (save-excursion
		   (forward-sexp 1)
		   (point))))
        (copy-region-as-kill-nomark beg end))
      ;; send the in-ns command to slime's repl:
      (set-buffer (slime-output-buffer))
      (unless (eq (current-buffer) (window-buffer)) 
        (pop-to-buffer (current-buffer) t)) 
      (goto-char (point-max)) 
      (insert "(in-ns '")
      (yank)
      (insert ")")
      (progn 
        (slime-repl-return) 
        (other-window 1)))))