buffer-other-eproject-files.el

;; a convienence function that lets us switch between source/header files in a project
(defun buffer-other-eproject-files ()
 (interactive)
 (let* 
  ((buffer-file (file-name-nondirectory (buffer-file-name)))
   (other-buffer-files
    (delq nil
          (mapcar (lambda (x) (and 
                               (equal (file-name-nondirectory (file-name-sans-extension x)) (file-name-sans-extension buffer-file)) 
                               (not (equal (file-name-nondirectory x) buffer-file))   
                               x)) (eproject-list-project-files)))))
  (when (> (length other-buffer-files) 0)
    ;; TO DO : Possibly prompt if there is more than one..
    (find-file (car other-buffer-files)))))