Re: Putting == before and after selected text

[Andreas Politz <politza@fh-trier.de>]

Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> writes:

> Andreas Politz <politza@fh-trier.de> writes:
>
>> Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> writes:
>>
>>> Hi,
>>>
>>> I would like some key to a command. This is not difficult, but this
>>> command should, once it is executed on some text, put `==' before the
>>> text (on the line before) and `==' after the text (on the line after).
>>>
>>> How could I do this?
>>
>> How about this ?
>>
>> (defun wrap-region-in-== (beg end)
>>   "Wrap lines contained in region with \"==\" marker.
>>
>> Interactively, if region is not active, operate on prefix-arg
>> lines around point."
>>   (interactive
>>    (if (use-region-p)
>>        (list (region-beginning) (region-end))
>>      (let ((arg (prefix-numeric-value current-prefix-arg)))
>>        (save-excursion
>>          (if (< arg 0)
>>              (forward-line)
>>            (beginning-of-line))
>>          (sort (list (point) (progn (forward-line arg) (point)))
>>                '<)))))
>>   (save-excursion
>>     (goto-char beg)
>>     (beginning-of-line)
>>     (insert "==")
>>     (newline)
>>     (goto-char end)
>>     (or (bolp) (forward-line 1))
>>     (insert "==")
>>     (newline)))
> Nice. I bound it to the F12 key, but I then encounter
>
> `if: Symbol's function definition is void: use-region-p' in the
> minibuffer. Why? Thanks.
>

Because it's a Emacs23 function and you are using Version 22.

The best would be to replace `use-region-p' with a call to this function
or simply inline it.

(defun region-active-p ()
  "Return t if Transient Mark mode is enabled and the mark is active."
  (and transient-mark-mode mark-active))

-ap