fortran insert continuation symbol (ampersand &) that match both fixed and free format.

fortran-ampersand.el

(defun fortran-insert-f90-continuation ()
  "Insert continuation symbol (ampersand &) that match both fixed and
free format.

If the inserted ampersand is the first non-blank character, just
insert it, otherwise, insert it at column 72 (zero-based index)
and insert another ampersand at column 6 on next line.

Also indent next line if `electric-indent-mode` is on."
  (interactive)
  (let ((beg (line-beginning-position))
	(end (point)))
    (setq s (buffer-substring-no-properties beg end))
    (if (string-match "^[ \t]*$" s)
	(insert "&")
      (progn
	(insert "\n     &")
	(previous-line)
	(move-to-column 72 t)
	(insert "&")
	(next-line)))
    (when electric-indent-mode
      (indent-for-tab-command))))