* Two potentially useful functions for org-element
@ 2014-08-06 23:01 Thorsten Jolitz
2014-08-07 8:59 ` Thorsten Jolitz
2014-08-08 8:03 ` Nicolas Goaziou
0 siblings, 2 replies; 4+ messages in thread
From: Thorsten Jolitz @ 2014-08-06 23:01 UTC (permalink / raw)
To: emacs-orgmode
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
#+results:
: tj/create-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."
(let* ((elem (org-element-at-point))
(plist (cadr elem))
(beg (org-element-property :begin elem))
(end (org-element-property :end elem))
strg)
(while args
(setq plist (plist-put plist (pop args) (pop args))))
(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)
(save-excursion (insert strg)))
strg)))))
#+end_src
#+results:
: tj/rewire-element
Here are a few usage examples:
#+begin_src emacs-lisp
(tj/create-element nil
:type 'src-block
:language "emacs-lisp"
:value "(+ 2 2)\n"
:parameters ":results raw"
:name "myblock"
:header '(":var x=5"))
#+end_src
#+results:
: #+NAME: myblock
: #+HEADER: :var x=5
: #+BEGIN_SRC emacs-lisp :results raw
: (+ 2 2)
: #+END_SRC
#+begin_src emacs-lisp :wrap org
(tj/create-element nil
:type 'headline
:level 2
:todo-keyword "DONE"
:priority 66
:title "Hello World"
:tags '("tag1" "tag2"))
#+end_src
#+results:
#+BEGIN_org
,** DONE [#B] Hello World :tag1:tag2:
#+END_org
Now eval next src-block
#+begin_src emacs-lisp
(defun test-fun ()
(tj/rewire-element 'append
:parameters ":results table :exports both"
:name (format "random-block-%d" (1+ (random 11)))
:header '(":var x=5")
:value (format "%s\n%s\n" '(+ 2 2) '(* 3 x))))
#+end_src
#+results:
: test-fun
and then, with point at beginning of following src-block, eval 'M-: (test-fun)'
#+BEGIN_SRC emacs-lisp :results raw
(+ 2 2)
#+END_SRC
#+NAME: random-block-6
#+HEADER: :var x=5
#+BEGIN_SRC emacs-lisp :results table :exports both
(+ 2 2)
(* 3 x)
#+END_SRC
--
cheers,
Thorsten
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Two potentially useful functions for org-element
2014-08-06 23:01 Two potentially useful functions for org-element Thorsten Jolitz
@ 2014-08-07 8:59 ` Thorsten Jolitz
2014-08-08 8:03 ` Nicolas Goaziou
1 sibling, 0 replies; 4+ messages in thread
From: Thorsten Jolitz @ 2014-08-07 8:59 UTC (permalink / raw)
To: emacs-orgmode
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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Two potentially useful functions for org-element
2014-08-06 23:01 Two potentially useful functions for org-element Thorsten Jolitz
2014-08-07 8:59 ` Thorsten Jolitz
@ 2014-08-08 8:03 ` Nicolas Goaziou
2014-08-08 8:27 ` Thorsten Jolitz
1 sibling, 1 reply; 4+ messages in thread
From: Nicolas Goaziou @ 2014-08-08 8:03 UTC (permalink / raw)
To: Thorsten Jolitz; +Cc: emacs-orgmode
Hello,
Thorsten Jolitz <tjolitz@gmail.com> writes:
> 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:
Element isn't really meant to provide tools to modify the buffer. It is
only a parser, i.e. buffer to parse tree transformation.
The reciprocal, i.e., modifying a parse tree in order to alter the
buffer may belong to another library. IIRC, this is the goal of
"org-sync" (from GSOC 2012). You may want to look into it.
Regards,
--
Nicolas Goaziou
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Two potentially useful functions for org-element
2014-08-08 8:03 ` Nicolas Goaziou
@ 2014-08-08 8:27 ` Thorsten Jolitz
0 siblings, 0 replies; 4+ messages in thread
From: Thorsten Jolitz @ 2014-08-08 8:27 UTC (permalink / raw)
To: emacs-orgmode
Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:
> Hello,
>
> Thorsten Jolitz <tjolitz@gmail.com> writes:
>
>> 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:
>
> Element isn't really meant to provide tools to modify the buffer. It is
> only a parser, i.e. buffer to parse tree transformation.
>
> The reciprocal, i.e., modifying a parse tree in order to alter the
> buffer may belong to another library. IIRC, this is the goal of
> "org-sync" (from GSOC 2012). You may want to look into it.
Sorry, did not read this before writing my other recent post ...
I will have a look at org-sync, but even if Element isn't really meant
to provide tools to modify the buffer, it seems to be tremendously
useful in doing so? The most limiting aspect I found is the missing
access to an elements content (see my parallel post wrt to this topic).
Otherwise 'rewiring' an elements internals looks like a huge
productivity booster compared to the usual buffer operations on the
textual representation. As long as the interpreter works as expected,
and it does!
--
cheers,
Thorsten
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-08-08 8:27 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-06 23:01 Two potentially useful functions for org-element Thorsten Jolitz
2014-08-07 8:59 ` Thorsten Jolitz
2014-08-08 8:03 ` Nicolas Goaziou
2014-08-08 8:27 ` Thorsten Jolitz
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).