I tried to describe the problem better as well as my thought process:
The `org-columns-compile-format' function has a bug in regexp.
When an empty parentheses `()` is in the 'column format string' -
and it always is when user do not provide a column title - then the
regexp can't capture the operator which is in curly brackets `{}`.
Try yourself with code below:
#+begin_src elisp
(org-columns-compile-format"%ITEM(){operator}")
; return => (("ITEM" "ITEM" nil nil nil))
; should be => (("ITEM" "ITEM" nil operator nil))
#+end_src
I'm not very skilled in regex, so following Ihor's advice I decided to
write the regex in the form of 'rx' which is more readable. Below is
the modified function:
#+begin_src elisp
(defun org-columns-compile-format-rx (fmt)
"Turn a column format string FMT into an alist of specifications.
The alist has one entry for each column in the format. The elements of
that list are:
property the property name, as an upper-case string
title the title field for the columns, as a string
width the column width in characters, can be nil for automatic width
operator the summary operator, as a string, or nil
printf a printf format for computed values, as a string, or nil
This function updates `org-columns-current-fmt-compiled'."
(setq org-columns-current-fmt-compiled nil)
(let ((start 0))
(while (string-match
(rx "%"
(optional (group (+ digit)))
(group (one-or-more (in alnum "_-")))
(optional "(" (group (one-or-more (not (any ")")))) ")")
(optional "{" (group (one-or-more (not (any "}")))) "}")
(zero-or-more space))
fmt start)
(setq start (match-end 0))
(let* ((width (and (match-end 1) (string-to-number (match-string 1
fmt))))
(prop (match-string-no-properties 2 fmt))
(title (or (match-string-no-properties 3 fmt) prop))
(operator (match-string-no-properties 4 fmt)))
(push (if (not operator) (list (upcase prop) title width nil nil)
(let (printf)
(when (string-match ";" operator)
(setq printf (substring operator (match-end 0)))
(setq operator (substring operator 0 (match-beginning 0))))
(list (upcase prop) title width operator printf)))
org-columns-current-fmt-compiled)))
(setq org-columns-current-fmt-compiled
(nreverse org-columns-current-fmt-compiled))))
#+end_src
I am checking if in this particular case it returns the same result
as 'org-columns-compile-format':
#+begin_src elisp
(org-columns-compile-format-rx "%ITEM(){operator}") ;; => (("ITEM" "ITEM" nil
nil nil))
#+end_src
#+begin_src elisp
(equal
(org-columns-compile-format "%ITEM(){operator}")
(org-columns-compile-format-rx "%ITEM(){operator}")) ;; => t
#+end_src
Yes, in this particular case it works the same. To make it easier to
capture the error, I only take a piece of code responsible for the
regexp:
#+begin_src elisp
(let ((text "%25ITEM(){operator}")
(pattern (rx "%"
(optional (group (+ digit)))
(group (one-or-more (in alnum "_-")))
(optional "(" (group (one-or-more (not (any ")")))) ")")
(optional "{" (group (one-or-more (not (any "}")))) "}")
(zero-or-more space))))
(if (string-match pattern text)
(mapcar (lambda (i) (match-string i text))
(number-sequence 0 (/ (length (match-data)) 2)))))
;=> ("%25ITEM" "25" "ITEM" nil)
#+end_src
Through trial and error, I came to a solution that provides correct
results. I changed the expression 'one-or-more' to 'zero-or-more' for
'title' and 'operator':
#+begin_src elisp
(let ((text "%25ITEM(){operator}")
(pattern (rx "%"
(optional (group (+ digit)))
(group (one-or-more (in alnum "_-")))
(optional "(" (group (zero-or-more (not (any ")")))) ")")
(optional "{" (group (zero-or-more (not (any "}")))) "}")
(zero-or-more space))))
(if (string-match pattern text)
(mapcar (lambda (i) (match-string i text))
(number-sequence 0 (/ (length (match-data)) 2)))))
;=> ("%25ITEM(){operator}" "25" "ITEM" "" "operator" nil)
#+end_src
This fixed a problem but also changed the return value. Now, when we
have empty parentheses '()', it will return an empty string
instead of null.
Therefore, in the function `org-columns-compile-format`, I added calls
to `org-string-nw-p` for the variables 'title' and 'operator'.
Additionally, I think that adding empty parentheses '()' should be removed
when we do not specify a 'column title'. Because it does not provide
any value. So I added another call to `org-string-nw-p' in function
`org-columns-new'.
Patch below:
<#part type="text/x-diff"
filename="~/.emacs.d/straight/repos/org/0001-lisp-org-colview.el-org-columns-compile-format-regex.patch"
disposition=inline>
<#/part>
Regards,
--
Slawomir Grochowski
