Toggle a character between "T" and "F"

Toggle a character between "T" and "F"

[Scott Waichler]

I am looking for a way to toggle the character under the cursor.  When
the character is "T", I'd like to hit a keystroke and change it to "F",
and vice versa.  I use these characters to set logical values in R
programming.  Can anyone tell me the lisp coded needed for this?

Thanks,
Scott Waichler

Re: Toggle a character between "T" and "F"

[Denis Bueno]

On 11 Mar 2005 10:10:44 -0800, Scott Waichler <scott.waichler@pnl.gov> wrote:
> I am looking for a way to toggle the character under the cursor.  When
> the character is "T", I'd like to hit a keystroke and change it to "F",
> and vice versa.  I use these characters to set logical values in R
> programming.  Can anyone tell me the lisp coded needed for this?

Possibly a kludge, but:

(defun toggle-t-r ()
  (interactive)
  (case (char-after)
    (?F (delete-char 1)
        (insert "T")
        (backward-char 1))
    (?T (delete-char 1)
        (insert "F")
        (backward-char 1))))


-- 
Denis Bueno
PGP: http://pgp.mit.edu:11371/pks/lookup?search=0xA1B51B4B&op=index

Re: Toggle a character between "T" and "F"

[Reiner Steib]

On Fri, Mar 11 2005, Scott Waichler wrote:

> I am looking for a way to toggle the character under the cursor.  When
> the character is "T", I'd like to hit a keystroke and change it to "F",
> and vice versa.  I use these characters to set logical values in R
> programming.  Can anyone tell me the lisp coded needed for this?

Maybe like this...

(defun rs-toggle-T-and-F ()
  "Toggle the characters `T' nor `F' at point."
  (interactive)
  (let ((case-fold-search nil))
    (cond ((looking-at "T")
	   (delete-char 1)
	   (insert "F"))
	  ((looking-at "F")
	   (delete-char 1)
	   (insert "T"))
	  (t (message "Neither `T' nor `F' at point")))))

Bye, Reiner.
-- 
       ,,,
      (o o)
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