Re: Why adding this write-file-hook makes save-buffer not work anymore!??

[Joakim Hove <hove@bccs.no>]

seberino@spawar.navy.mil (Christian Seberino) writes:


> Thanks for your help.  What makes my function return non-nil
> and how do I make it return nil???

The last evaluated statement of your function is the return value,
i.e. in your function the return value is the result of:

   (goto-char original-pos)

The documentation of (goto-char ) does not say, but the little test
function:

  (defun testit ()
    (interactive)
    (message "Point-max: %s" (goto-char (point-max))) (sleep-for 5)
    (message "Point-min: %s" (goto-char (point-min))) (sleep-for 5))

quickly reveals that (goto-char ) returns the value of the point it
has moved to (at least when it succeeds), i.e. the value of
original-pos in your case.

>> >    (defun cs-delete-trailing-whitespace() (interactive)
>> >       (delete-trailing-whitespace)
>> >       (let ((original-pos (point)))
>> >          (goto-char (point-max))
>> >          (delete-blank-lines)
>> >          (goto-char original-pos)))

To return 'nil just change the last lines:

;; snip
  (goto-char original-pos)
  'nil))

HTH - Joakim

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