Hi Bastien, At Wed, 27 Jul 2011 17:28:36 +0200, Bastien wrote: > > Hi David, > > David Maus <[email protected]> writes: > > > I highly recommend to not use this macro but to build the intended > > functionality with separate building blocks: Factor out the flesh of > > the respective functions (e.g. org-schedule) and use org-map-entries > > to map. As far as I can see, the latter provides all we need: > > I took this road. > > > The first patch manually reverts the commit you are commenting. > > The third patch implements the "loop" functionality by just using > `org-map-entries', not a macro. > > I'm sure we could have an `org-loop' macro factoring out the duplicate > code in the new `org-schedule' and `org-deadline'. If you have time to > look at this, that will greatly help.
My vacation starts saturday so I do have time and really like to get
my hands dirty with some Lisp hacking.
Now for the macro (2 iterations later): It might not be necessary to
factor out the functions if the function that invokes the looping
can be called recursively.
E.g.
#+begin_src emacs-lisp
(defmacro org-with-headline-siblings (function)
"Apply function to siblings of current headline."
`(org-map-entries ,function 'siblings))
(defun org-schedule ()
(...)
(if (or (not (org-region-active-p))
(not org-loop-over-siblings))
(let ((org-loop-over-siblings nil))
(org-with-headline-siblings 'org-schedule))))
#+end_src
If the function takes arguments, we need to wrap the function call at
the end in a lambda.
And if this works out, we are almost there:
#+begin_src emacs-lisp
(defmacro org-with-headline-siblings-maybe (predicate &rest body)
"Execute body on current headline's siblings if PREDICATE."
`(progn
,@body
(if ,predicate
(org-map-entries '(lambda () (progn ,@body)) 'siblings))))
#+end_src
>
> > Another abstraction: Instead
> > 'org-loop-over-siblings-with-active-region' something like:
> > 'org-loop-over-headlines-with-active-region' that can be set to a
> > symbol or a list of symbols indicating which headings to loop over
> > (e.g. 'siblings, 'children, ...).
>
> The variable is now called `org-loop-over-headlines-in-active-region'
> and understand these kind of values:
>
> - nil: don't loop
> - t: loop over all headlines
> - "MATCH": a tag/property/todo match to loop over matching headlines
>
Nice. These values can fit into org-map-entries MATCH argument, can't
they?
We would have:
org-loop-over-headlines-in-active-region
/
(org-map-entries FUNC &optional MATCH SCOPE &rest SKIP)
/ \
our function region is active
I'm not quite sure, but
a/ we move the check for an active region to org-map-entries: If
SCOPE is 'region but no region is active, org-map-entries simply
returns.
b/ we modify org-map-entries, so that a MATCH of nil means: No
match.
This way we can express the predicate as a condition of map.
#+begin_src emacs-lisp
(defmacro org-loop-over-headlines (&rest body)
`(progn
,@body
(org-map-entries '(lambda () (progn ,@body))
org-loop-over-headlines-in-active-region 'region)))
#+end_src
> If you can test these patches and send some feedback, that'd be nice!
Scheduled for Sunday.
Best,
-- David
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