Re: [O] some lisp help (for complete 0-knowledge lisp emacs user :))

[Thorsten Jolitz]

Xebar Saram <address@hidden> writes:

> Hi list
>
> so i know i should start to really learn lisp but real life (uni work,
> family etc) doesn't really allow me so im marking my 1st year
> anniversary of using emacs without grasping lisp (plus i am in
> generally coding inept :))
>
> in any case.... :) i have this handy lisp snippet that i find very
> useful and maybe some others in the list will find as well. it allows
> to quick convert lines of text into org src/example blocks:
>
> (defun z-wrap-cblock-lisp ()
> "Wrap region in quote block"
> (interactive)
> (save-excursion
> (save-restriction
> (and
> (region-active-p)
> (use-region-p)
> (narrow-to-region (region-beginning) (region-end)))
> (goto-char (point-min))
> (insert "#+BEGIN_SRC emacs-lisp :results none\n")
> (goto-char (point-max))
> (insert "#+END_SRC\n")
> (deactivate-mark))))
>
> this works well but has some annoying flaws like you have to first
> manually mark the region you want to convert etc
>
> i was wondering:
>
> a)can some lisp coding master show me how to make this function auto
> select the line//X user defined lines/smart paragraph selection before
> it wraps it in the org block
> b)any improvement ideas from the community?

Try this:

#+begin_src emacs-lisp
  (defun tj/wrap-sexp-in-elisp-src-block ()
    "Wrap sexp at point in elisp src block"
    (interactive)
    (let* ((marker (point-marker))
           (beg (point))
           (end (save-excursion
                  (forward-sexp) (point)))
           (cut-strg (buffer-substring beg end)))
      (delete-region beg end)
      (goto-char (marker-position marker))
      (insert
       (format
        "\n#+begin_src emacs-lisp\n%s\n#+end_src\n"
        cut-strg))
      (set-marker marker nil)))
#+end_src

#+results:
: tj/wrap-sexp-in-elisp-src-block

MWE:

(defun foo ()
  "do foo"
   (message "foo"))

1. with point at the opening paren:


#+begin_src emacs-lisp
(defun foo ()
  "do foo"
   (message "foo"))
#+end_src

2. with point at the 'd' of defun:

(
#+begin_src emacs-lisp
defun
#+end_src
 foo ()
  "do foo"
   (message "foo"))

3. with point between 'do foo':

(defun foo ()
  "do
#+begin_src emacs-lisp
 foo
#+end_src
"
   (message "foo"))


This is actually quite useful, will add it to my init file (since I
frequently get 'org-babel-demarcate-block: Args out of range' errors
when trying to wrap a region).

Note that the behaviour depends a bit on the major-mode. In emacs-lisp
mode, a string is seen as one sexp, thus with point at the first
double-quote of 

"hello world"

I get

#+begin_src emacs-lisp
"hello world"
#+end_src

while in this message-mode buffer I get

#+begin_src emacs-lisp
"hello
#+end_src
 world"

-- 
cheers,
Thorsten