[PATCH 1/2] ox-texinfo: Turn a description list item with "+" bullet into @itemx

[Jonas Bernoulli <jonas@bernoul.li>]

* doc/org-manual.org (Plain lists in Texinfo export): Reorder and
document new functionality.
* lisp/ox-texinfo.el (org-texinfo--filter-parse-tree)
(org-texinfo--normalize-items): New functions.
* lisp/ox-texinfo.el (org-texinfo-item): Use @itemx or @item
depending on the used bullet.
---
 doc/org-manual.org | 37 ++++++++++++++++++++++++++-----------
 lisp/ox-texinfo.el | 39 +++++++++++++++++++++++++++++++++++----
 2 files changed, 61 insertions(+), 15 deletions(-)

diff --git a/doc/org-manual.org b/doc/org-manual.org
index b65e2f173..b8bb391c2 100644
--- a/doc/org-manual.org
+++ b/doc/org-manual.org
@@ -15236,6 +15236,23 @@ This paragraph is preceded by...
 :DESCRIPTION: List attributes.
 :END:
 
+#+cindex: lettered lists, in Texinfo export
+#+cindex: enum, Texinfo attribute
+The Texinfo export back-end converts unordered and ordered lists in
+the Org file using the default command =@itemize=.
+
+Ordered lists are numbered when exported to Texinfo format.  Such
+numbering obeys any counter (see [[*Plain Lists]]) in the first item of
+the list.  The =:enum= attribute also let you start the list at a
+specific number, or switch to a lettered list, as illustrated here:
+
+#+begin_example
+#+ATTR_TEXINFO: :enum A
+1. Alpha
+2. Bravo
+3. Charlie
+#+end_example
+
 #+cindex: @samp{ATTR_TEXINFO}, keyword
 #+cindex: two-column tables, in Texinfo export
 #+cindex: table-type, Texinfo attribute
@@ -15262,7 +15279,7 @@ entry in the first column of the table.
 The following example illustrates all the attributes above:
 
 #+begin_example
-,#+ATTR_TEXINFO: :table-type vtable :sep , :indic asis
+,#+attr_texinfo: :table-type vtable :sep , :indic asis
 - foo, bar :: This is the common text for variables foo and bar.
 #+end_example
 
@@ -15277,18 +15294,16 @@ This is the common text for variables foo and bar.
 @end table
 #+end_example
 
-#+cindex: lettered lists, in Texinfo export
-#+cindex: enum, Texinfo attribute
-Ordered lists are numbered when exported to Texinfo format.  Such
-numbering obeys any counter (see [[*Plain Lists]]) in the first item of
-the list.  The =:enum= attribute also let you start the list at
-a specific number, or switch to a lettered list, as illustrated here
+In description lists the used bullet is significant when exporting to
+Texinfo; when in doubt, then use =-=.  An item that uses =+= instead
+becomes a new entry in the first column of the table.  The above
+output can also be produced with:
 
 #+begin_example
-#+ATTR_TEXINFO: :enum A
-1. Alpha
-2. Bravo
-3. Charlie
+,#+attr_texinfo: :table-type vtable :indic asis
+- foo ::
++ bar ::
+  This is the common text for foo and bar.
 #+end_example
 
 *** Tables in Texinfo export
diff --git a/lisp/ox-texinfo.el b/lisp/ox-texinfo.el
index b0125894a..35862357d 100644
--- a/lisp/ox-texinfo.el
+++ b/lisp/ox-texinfo.el
@@ -418,6 +418,11 @@ (defun org-texinfo--filter-section-blank-lines (headline _backend _info)
   "Filter controlling number of blank lines after a section."
   (replace-regexp-in-string "\n\\(?:\n[ \t]*\\)*\\'" "\n\n" headline))
 
+(defun org-texinfo--filter-parse-tree (tree backend info)
+  "Normalize headlines and items."
+  (org-texinfo--normalize-headlines tree backend info)
+  (org-texinfo--normalize-items tree info))
+
 (defun org-texinfo--normalize-headlines (tree _backend info)
   "Normalize headlines in TREE.
 
@@ -443,6 +448,29 @@ (defun org-texinfo--normalize-headlines (tree _backend info)
     info)
   tree)
 
+(defun org-texinfo--normalize-items (tree info)
+  "Normalize items in TREE.
+
+INFO is a plist used as a communication channel.
+
+Items in description lists that use the \"+\" bullet are
+converted to `@itemx'.  If another item is followed by such an
+item, then the first item should not be followed by a space,
+which this function takes care of.
+
+Return new tree."
+  (org-element-map tree 'plain-list
+    (lambda (plain-list)
+      (when (eq (org-element-property :type plain-list) 'descriptive)
+        (let ((contents (org-element-contents plain-list)))
+          (while (setq item (pop contents))
+            (let ((next-item (car contents)))
+              (when (and next-item
+                         (equal (org-element-property :bullet next-item) "+ "))
+                (org-element-put-property item :post-blank 0)))))))
+    info)
+  tree)
+
 (defun org-texinfo--find-verb-separator (s)
   "Return a character not used in string S.
 This is used to choose a separator for constructs like \\verb."
@@ -998,13 +1026,16 @@ (defun org-texinfo-item (item contents info)
 		     (let ((tag (org-export-data tag info)))
 		       (if split
 			   (split-string tag (regexp-quote split) t "[ \t\n]+")
-			 (list tag))))))
+			 (list tag)))))
+         (command (if (equal (org-element-property :bullet item) "+ ")
+                      "@itemx"
+                    "@item")))
     (format "%s\n%s"
 	    (pcase items
-	      (`nil "@item")
-	      (`(,item) (concat "@item " item))
+	      (`nil command)
+	      (`(,item) (concat command " " item))
 	      (`(,item . ,items)
-	       (concat "@item " item "\n"
+	       (concat command " " item "\n"
 		       (mapconcat (lambda (i) (concat "@itemx " i))
 				  items
 				  "\n"))))
-- 
2.34.1