gistfile1.txt

(defun camelcase-region (start end)
  "Changes region from snake_case to camelCase"
  (interactive "r")
  (save-restriction (narrow-to-region start end)
                    (goto-char (point-min))
                    (while (re-search-forward "_\\(.\\)" nil t)
		      (replace-match (upcase (match-string 1))))))