[Orgmode] Useful utility function: org-sort-multi

[Ryan C. Thompson]

I found myself having to sort by multiple criteria, and I was doing it 
with multiple calls to org-sort-entries-or-items. Then I decided to 
abstract the repetition into a function. Here it is:

(defun org-sort-multi (&rest sort-types)
  "Sort successively by a list of criteria, in descending order of 
importance.
For example, sort first by TODO status, then by priority, then by date, 
then alphabetically, case-sensitive.
Each criterion is either a character or a cons pair (BOOL . CHAR), where 
BOOL is whether or not to sort case-sensitively, and CHAR is one of the 
characters defined in ``org-sort-entries-or-items''.
So, the example above could be accomplished with:
 (org-sort-multi ?o ?p ?t (t . ?a))"
  (interactive)
  (mapc #'(lambda (sort-type)
            (when (characterp sort-type) (setq sort-type (cons nil 
sort-type)))
            (org-sort-entries-or-items (car sort-type) (cdr sort-type)))
        (reverse sort-types)))

Note the call to reverse. This makes it so that the first criterion you 
provide is the dominant criterion. Try it out to see how it works, and 
let me know if there's a better way to pass the arguments.

Just as an example, the particular sorting function I wanted to write 
now becomes this:

(defun org-sort-custom ()
  "Sort children of node by todo status and by priority and by date, so 
the * TODO [#A] items with latest dates go to the top."
  (interactive)
  (org-sort-multi ?o ?p ?T))