Re: Keep-only-column

[Marc Tfardy <m-t-o@web.de>]

weber wrote:
 > On 8 fev, 16:15, "weber" <hug...@gmail.com> wrote:
 >> hello again!
 >> Quite frequently I paste stuff which is space-separated.
 >> I would really like a function that would let me select a region and
 >> keep only a column, deleting all the rest.
 >> Anyone knows how I could implement something like this?
 >> I can do it with regexps, but then I have to come up with a new one
 >> every time...
 >> TIA
 >> HS
 >
 > I think the format of "stuff" can't be understood from above :) Here
 > it is:
 >
 > variable BLABLA  =     438438
 > variable LABLAC  =     312
 > variable DAUSH  =     43538
 >
 > Apply to that region: keep-only-column 2 makes it:
 > BLABLA
 > LABLAC
 > DAUSHD



Here my draft. Probalby inefficient, but it does the job.


(defun trim-rectangle (start end)
   "Trims region to rectangle."
   (interactive "r")
   (save-excursion
     (let ((offset 0)
           (width 0)
           (lines (count-lines start end))
           (i 0))
       (goto-char start)
       (beginning-of-line)
       (setq offset (- start (point)))
       (goto-char end)
       (beginning-of-line)
       (forward-char offset)
       (setq width (- end (point)))
       (goto-char start)
       (while (< i lines)
         (beginning-of-line)
         (delete-region (point) (+ (point) offset))
         (forward-char width)
         (delete-region (point) (line-end-position))
         (end-of-line)
         (forward-char)
         (setq i (+ i 1))))))

HTH

regards

Marc