Updating Clojure namespaces

Continuing my experimentations with Emacs Lisp, I created a function that automatically updates the namespace of a Clojure buffer in conformity with its pathname. This is useful after renaming a file, since changing a file pathname requires to change its namespace, which is sometimes annoying to do by hand.

	(defun clojure-correct-ns
	()
	"Returns the namespace name that the file should have."
	(let* ((nsname ())
	(dirs (reverse (split-string (buffer-file-name) "/")))
	(aftersrc nil))
	(dolist (dir dirs)
	(when (not aftersrc)
	(if (or (string= dir "src") (string= dir "test"))
	(setq aftersrc t)
	(setq nsname (append nsname (list dir "."))))))
	(when nsname
	(replace-regexp-in-string "_" "-" (substring (apply 'concat (reverse nsname)) 1 -4)))))
	(defun clojure-update-ns
	()
	"Updates the namespace of the current buffer. Useful if a file has been renamed."
	(interactive)
	(let ((nsname (clojure-correct-ns)))
	(when nsname
	(clojure-find-ns) ;; function defined in clojure-mode
	(replace-match nsname nil nil nil 4))))

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Once added to your .emacs file, you can call it with:

M-x clojure-update-ns

It assumes clojure-mode is already loaded.