Re: line-move-down-up

[A Soare <as1789@gmail.com>]

Deniz Dogan <deniz.a.m.dogan <at> gmail.com> writes:

> 
> 2011/4/18 A Soare <as1789 <at> gmail.com>:
> >> Also, (next-line n) (beginning-of-line) could be replaced
> >> with (beginning-of-line (1+ n)).
> >>
> >
> > This is wrong in general.
> >
> 
> Care to elaborate?
> 
> 


(progn
  (goto-char (point-max))
  (insert ? )
  (beginning-of-line 4))

The definitive version I keep in .emacs is so:


;; move line

(defun line-move-down (n)
  (if (> (point-max) (point-at-eol))
      (let ((column (current-column) )
            (line (delete-and-extract-region (point-at-bol) (1+ (point-at-eol)))))
        (forward-line n)
        (insert-string line)
        (backward-char)
        (move-to-column column) ) ) )

(define-key global-map [(meta up)]
  (lambda (&optional n)
    (interactive "P")
    (line-move-down (if (numberp n) (- n) -1) ) ) )

(define-key global-map [(meta down)]
  (lambda (&optional n)
    (interactive "P")
    (line-move-down (if (numberp n) n 1) )  ) )