From: Thorsten Jolitz <tjolitz@gmail.com>
To: emacs-orgmode@gnu.org
Subject: Re: Two potentially useful functions for org-element
Date: Thu, 07 Aug 2014 10:59:22 +0200 [thread overview]
Message-ID: <87oavwad5h.fsf@gmail.com> (raw)
In-Reply-To: 87wqalql21.fsf@gmail.com
Thorsten Jolitz <tjolitz@gmail.com> writes:
Hi List,
> now that I understand the 'org-element API' a bit better, I think that
> the following two functions can be very useful for creating and
> modifying Org elements without the usual point movements, regexp
> searches and string operations in a buffer:
>
> #+begin_src emacs-lisp
> ;; might become `org-element-create'
> (defun* tj/create-element (&optional insert-p &rest args &key (type 'headline) &allow-other-keys)
> "Create Org element, maybe insert at point."
> (let ((strg (org-element-interpret-data
> (list type args))))
> (if insert-p (insert strg) strg)))
> #+end_src
I made the second 'rewire element' function smarter so that it can now
reuse the old value when setting a new value for a property of the
'rewired' element:
#+begin_src emacs-lisp
;; might become `org-element-rewire'
(defun* tj/rewire-element (&optional replace &rest args &key type &allow-other-keys)
"Rewire element at point, maybe replace it.
The former value of an element property can be reused in the
creation of a new value by giving a `lambda' expession with one
function argument instead of a value to a key. That argument will
then be replaced by the property's former value when applying the
function."
(let* ((elem (org-element-at-point))
(plist (cadr elem))
(beg (org-element-property :begin elem))
(end (org-element-property :end elem))
strg)
(while args
(let* ((key (pop args))
(val-or-fun (pop args))
(old-val (org-element-property key elem))
(new-val
(if (functionp val-or-fun)
(apply val-or-fun (list old-val))
val-or-fun)))
(setq plist (plist-put plist key new-val))))
(setq strg (org-element-interpret-data
(list (or type (org-element-type elem)) plist)))
(case replace
(append (save-excursion (goto-char end) (insert strg)))
(prepend (goto-char beg) (insert strg))
(t (if replace
(let ((marker (save-excursion
(goto-char end) (point-marker))))
(delete-region beg end)
(goto-char marker)
(set-marker marker nil)
(save-excursion (insert strg)))
strg)))))
#+end_src
#+results:
: tj/rewire-element
Here a few examples, all of them assuming point is at beginning of
this src-block if not stated otherwise:
#+begin_src emacs-lisp
(+ 2 2)
#+end_src
1. do M-: [content-of-next-src-block]
#+begin_src emacs-lisp
(tj/rewire-element 'append
:name (format "rewired-%d" (1+ (random 10))))
#+end_src
#+NAME: rewired-7
#+BEGIN_SRC emacs-lisp
(+ 2 2)
#+END_SRC
2. do M-: [content-of-next-src-block]
#+begin_src emacs-lisp
(tj/rewire-element 'append
:name (lambda (_old_)
(if _old_
(format "rewired-%d"
(* (string-to-number
(car
(last
(split-string _old_ "-" t))))
(1+ (random 10))))
(format "rewired-%d" (1+ (random 10)))))
:language "picolisp")
#+end_src
gives
#+NAME: rewired-2
#+BEGIN_SRC picolisp
(+ 2 2)
#+END_SRC
when called on the original src-block, but
#+NAME: rewired-63
#+BEGIN_SRC picolisp
(+ 2 2)
#+END_SRC
when called on the result of usage example 1 (with name rewired-7).
3. do M-: [content-of-next-src-block]
#+begin_src emacs-lisp
(tj/rewire-element 'append
:value (lambda (_old_)
(concat
"(message \"%d\" "
(car
(split-string
_old_ "\n" t)) ")\n"))
:parameters ":results raw")
#+end_src
gives
#+BEGIN_SRC emacs-lisp :results raw
(message "%d" (+ 2 2))
#+END_SRC
--
cheers,
Thorsten
next prev parent reply other threads:[~2014-08-07 8:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-06 23:01 Two potentially useful functions for org-element Thorsten Jolitz
2014-08-07 8:59 ` Thorsten Jolitz [this message]
2014-08-08 8:03 ` Nicolas Goaziou
2014-08-08 8:27 ` Thorsten Jolitz
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