[O] new tag query parser [4/5] -- a few ``illuminating'' examples

[Christopher Genovese]

#+TITLE: New Tag Query Parser: A Few Illuminating Examples

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* Preliminaries  Point 207

  The Point # labels on the headings give the point values for the
  beginning of the heading. To make this accurate, we need to

  standardize tag placemnet. Using M-: or equivalent means,
  execute the following in this buffer:

  
  #+begin_src emacs-lisp

  (set (make-local-variable 'org-tags-column) -80)
  (set (make-local-variable 'org-todo-keywords)

           '((sequence "TODO" "WAIT" "DONE")))
  #+end_src

  If necessary, do C-u C-c on a headline to realign the tags.


* Parenthesized Expressions Point 714                                  :feature:


  Fully parenthesized expressions are allowed in the tag query strings.
  A - selector before the parenthesized _expression_ acts as a logical

  not. These expressions can include an old-style /!? todo-query string
  as well, which extends to the closing paren.

** TODO Paren Examples Point 1057                                :example:paren:

   + (org-map-entries 'point "(example&HEADING={^Paren}/TODO)")

   + (org-map-entries 'point "HEADING={Paren} & -(extra | LEVEL = 1)")  
   + (org-map-entries 'point "(feature | LEVEL == 2)({^p}/WAIT|TODO)")

   The first two should give 1057, the third (1057 1492).
    

* Another Point 1411                                                     :extra:
** WAIT This is not a feature example Point 1492                       :pretend:

** We can manipulate and combine whole expressions Point 1573

   + (org-map-entries 'point "-(feature&LEVEL=2)")

   + (org-map-entries 'point "-(feature|LEVEL==2)|{^$}")

  Note that inheritance can affects the tag matches; it might

  be nice to be able to distinguish this in searches.
  Note also that the original matcher fails silently here.

* Braces and Spaces AAA  Point 1921                                    :feature:

** DONE Just a marker AAAAAA Point 2002
** TODO Simple Examples AAAA Point 2042                         :example:syntax:

   + (org-map-entries 'point "example & TODO <> \"DONE\")
   + (org-map-entries 'point "example/!")

   + (org-map-entries 'point "example | HEADING = { A\\{{3,4\\}}[^A]}")
   + Allows = or == for equality operator.

** [#A] Ok Point 2338
** [#B] This is fast Point 2360

   + (org-map-entries 'point "PRIORITY=\"B\"")


Many more examples are available in the test suite. Do C-u M-x run-tag-query-tests
to see them.