Bug: [PATCH] Use crm for tag completion [9.4.6 (9.4.6-gab9f2a @ /home/ionasal/.emacs.d/elpa/org-9.4.6/)]

[Allen Li]

Org mode's tag completion commands all use a custom completion function,
which makes it difficult for alternative completion functions to support
well.

Emacs already has a function for reading multiple things,
completing-read-multiple, which can be used for the tag completion use
case.

I have attached a patch for this change, which I have tested manually a
few times and also fixed the existing tests.  I have tested this with
vertico, which claims to strictly follow Emacs's completion API.

>From 933dc914694c14889af86c06ba0a8bbd88a316cf Mon Sep 17 00:00:00 2001
From: Allen Li <darkfeline@felesatra.moe>
Date: Thu, 8 Jul 2021 21:35:34 -0700
Subject: [PATCH] org: Use crm for completing tags

Change various places which use `completing-read' to read tags using a
custom completion function to instead use `completing-read-multiple'
with a completion table instead.

This makes tab completion play better with alternative completion
frameworks such as vertico, selectrum, etc.

`org-change-tag-in-region' only reads a single tag, so it is changed
to use a completion table with `completing-read'.  This also makes it
play better with alternative completion frameworks.

Note that there is still one use for `org-tags-completion-function',
which is for completing tag matches.  Completing tag matches is
different from completing lists of tags since the separators (+, -,
etc) have semantic meaning.  This commit does not address that use
case.

* lisp/org-capture.el (org-capture-fill-template): Changed to use
completing-read-multiple.
* lisp/org.el (org-set-tags-command): Changed to use
completing-read-multiple.
(org-change-tag-in-region): Changed to use a simple completion table.
* testing/lisp/test-org.el (test-org/set-tags-command): Fixed tests.
* etc/ORG-NEWS (Tag completion now uses =completing-read-multiple=):
Added news.
---
 etc/ORG-NEWS             |  6 +++++
 lisp/org-capture.el      | 12 +++++-----
 lisp/org.el              | 18 +++++++++------
 testing/lisp/test-org.el | 50 ++++++++++++++++------------------------
 4 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 3f3971961..719ac3547 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -409,6 +409,12 @@ The function does not allow for a third optional parameter 
anymore.
 If a babel src block produces a raw LaTeX environment, it will now be
 recognised as a result, and so replaced when re-evaluated.
 
+*** Tag completion now uses =completing-read-multiple=
+
+Tag completion now uses =completing-read-multiple= with a simple
+completion table, which should allow better interoperability with
+custom completion functions.
+
 * Version 9.4
 ** Incompatible changes
 *** Possibly broken internal file links: please check and fix
diff --git a/lisp/org-capture.el b/lisp/org-capture.el
index 5ecec6309..c51744680 100644
--- a/lisp/org-capture.el
+++ b/lisp/org-capture.el
@@ -69,6 +69,7 @@
 (declare-function org-table-goto-line "org-table" (N))
 
 (defvar dired-buffers)
+(defvar crm-separator)
 (defvar org-end-time-was-given)
 (defvar org-keyword-properties)
 (defvar org-remember-default-headline)
@@ -1739,12 +1740,11 @@ The template may still contain \"%?\" for cursor 
positioning."
                            (org-add-colon-after-tag-completion t)
                            (ins (mapconcat
                                  #'identity
-                                 (org-split-string
-                                  (completing-read
-                                   (if prompt (concat prompt ": ") "Tags: ")
-                                   'org-tags-completion-function nil nil nil
-                                   'org-tags-history)
-                                  "[^[:alnum:]_@#%]+")
+                                 (let ((crm-separator "[ \t]*:[ \t]*"))
+                                    (completing-read-multiple
+                                    (if prompt (concat prompt ": ") "Tags: ")
+                                    org-last-tags-completion-table nil nil nil
+                                    'org-tags-history))
                                  ":")))
                       (when (org-string-nw-p ins)
                         (unless (eq (char-before) ?:) (insert ":"))
diff --git a/lisp/org.el b/lisp/org.el
index 4fd8b6fa6..ed3ee3a1c 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -201,6 +201,8 @@ Stars are put in group 1 and the trimmed body in group 2.")
 ;; load languages based on value of `org-babel-load-languages'
 (defvar org-babel-load-languages)
 
+(defvar crm-separator)  ; dynamically scoped param
+
 ;;;###autoload
 (defun org-babel-do-load-languages (sym value)
   "Load the languages defined in `org-babel-load-languages'."
@@ -12054,12 +12056,14 @@ in Lisp code use `org-set-tags' instead."
                      inherited-tags
                      table
                      (and org-fast-tag-selection-include-todo 
org-todo-key-alist))
-                  (let ((org-add-colon-after-tag-completion (< 1 (length 
table))))
-                    (org-trim (completing-read
-                               "Tags: "
-                               #'org-tags-completion-function
-                               nil nil (org-make-tag-string current-tags)
-                               'org-tags-history)))))))
+                  (let ((org-add-colon-after-tag-completion (< 1 (length 
table)))
+                         (crm-separator "[ \t]*:[ \t]*"))
+                    (string-join (completing-read-multiple
+                                  "Tags: "
+                                  org-last-tags-completion-table
+                                  nil nil (org-make-tag-string current-tags)
+                                  'org-tags-history)
+                                  ":"))))))
          (org-set-tags tags)))))
     ;; `save-excursion' may not replace the point at the right
     ;; position.
@@ -12139,7 +12143,7 @@ This works in the agenda, and also in an Org buffer."
                     (org-global-tags-completion-table))
                  (org-global-tags-completion-table))))
           (completing-read
-           "Tag: " 'org-tags-completion-function nil nil nil
+           "Tag: " org-last-tags-completion-table nil nil nil
            'org-tags-history))
         (progn
           (message "[s]et or [r]emove? ")
diff --git a/testing/lisp/test-org.el b/testing/lisp/test-org.el
index 95ffb0a80..de3c6f3c9 100644
--- a/testing/lisp/test-org.el
+++ b/testing/lisp/test-org.el
@@ -6969,8 +6969,8 @@ Paragraph<point>"
   (should
    (equal "* H1 :foo:"
          (org-test-with-temp-text "* H1"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -6979,8 +6979,8 @@ Paragraph<point>"
   (should
    (equal "* H1 :foo:\nContents"
          (org-test-with-temp-text "* H1\n<point>Contents"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -6988,30 +6988,20 @@ Paragraph<point>"
   (should-not
    (equal "* H1 :foo:\nContents2"
          (org-test-with-temp-text "* H1\n<point>Contents2"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
            (org-at-heading-p))))
-  ;; Strip all forbidden characters from user-entered tags.
-  (should
-   (equal "* H1 :foo:"
-         (org-test-with-temp-text "* H1"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ": foo *:")))
-             (let ((org-use-fast-tag-selection nil)
-                   (org-tags-column 1))
-               (org-set-tags-command)))
-           (buffer-string))))
   ;; When a region is active and
   ;; `org-loop-over-headlines-in-active-region' is non-nil, insert the
   ;; same value in all headlines in region.
   (should
    (equal "* H1 :foo:\nContents\n* H2 :foo:"
          (org-test-with-temp-text "* H1\nContents\n* H2"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-loop-over-headlines-in-active-region t)
                    (org-tags-column 1))
@@ -7023,8 +7013,8 @@ Paragraph<point>"
   (should
    (equal "* H1\nContents\n* H2 :foo:"
          (org-test-with-temp-text "* H1\nContents\n* H2"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-loop-over-headlines-in-active-region nil)
                    (org-tags-column 1))
@@ -7043,8 +7033,8 @@ Paragraph<point>"
   (should
    (equal ":foo:"
          (org-test-with-temp-text "* <point>"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -7053,8 +7043,8 @@ Paragraph<point>"
   (should
    (equal "* H1 :foo:"
          (org-test-with-temp-text "* H1"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -7063,8 +7053,8 @@ Paragraph<point>"
   (should
    (equal "* H1 :foo:"
          (org-test-with-temp-text "*<point>* H1"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -7073,8 +7063,8 @@ Paragraph<point>"
   (should
    (equal " b :foo:"
          (org-test-with-temp-text "* a<point> b"
-           (cl-letf (((symbol-function 'completing-read)
-                      (lambda (&rest args) ":foo:")))
+           (cl-letf (((symbol-function 'completing-read-multiple)
+                      (lambda (&rest args) '("foo"))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
@@ -7083,9 +7073,9 @@ Paragraph<point>"
   (should
    (equal "b :foo:"
          (org-test-with-temp-text "* a :foo:\n** <point>b :foo:"
-           (cl-letf (((symbol-function 'completing-read)
+           (cl-letf (((symbol-function 'completing-read-multiple)
                       (lambda (prompt coll &optional pred req initial &rest 
args)
-                        initial)))
+                        (list initial))))
              (let ((org-use-fast-tag-selection nil)
                    (org-tags-column 1))
                (org-set-tags-command)))
-- 
2.32.0