org-export: New function `org-export-get-parent'

* contrib/lisp/org-export.el (org-export-get-parent): New function.
(org-export-data, org-export-get-previous-element,
org-export-get-next-element): Use new function.
* EXPERIMENTAL/org-e-ascii.el (org-e-ascii-item): Use new function.
  Refactor code.
(org-e-ascii-paragraph): Use new function.
* EXPERIMENTAL/org-e-latex.el (org-e-latex-item): Use new function.
* EXPERIMENTAL/org-e-html.el (org-e-html-item): Use new function.
* EXPERIMENTAL/org-e-odt.el (org-e-odt-item): Use new function.

EXPERIMENTAL/org-e-ascii.el

@@ -1279,34 +1279,32 @@ contextual information."
 	 ;; First parent of ITEM is always the plain-list.  Get
 	 ;; `:type' property from it.
 	 (org-list-bullet-string
-	  (let ((type (org-element-property
-		       :type (car (org-export-get-genealogy item info)))))
-	    (cond
-	     ((eq type 'descriptive)
-	      (concat
-	       (org-export-secondary-string
-		(org-element-property :tag item) 'e-ascii info) ": "))
-	     ((eq type 'ordered)
-	      ;; Return correct number for ITEM, paying attention to
-	      ;; counters.
-	      (let* ((struct (org-element-property :structure item))
-		     (bul (org-element-property :bullet item))
-		     (num
-		      (number-to-string
-		       (car (last (org-list-get-item-number
-				   (org-element-property :begin item)
-				   struct
-				   (org-list-prevs-alist struct)
-				   (org-list-parents-alist struct)))))))
-		(replace-regexp-in-string "[0-9]+" num bul)))
-	     (t (let ((bul (org-element-property :bullet item)))
-		  ;; Change bullets into more visible form if UTF-8 is active.
-		  (if (not (eq (plist-get info :ascii-charset) 'utf-8)) bul
+	  (case (org-element-property :type (org-export-get-parent item info))
+	    (descriptive
+	     (concat
+	      (org-export-secondary-string
+	       (org-element-property :tag item) 'e-ascii info) ": "))
+	    (ordered
+	     ;; Return correct number for ITEM, paying attention to
+	     ;; counters.
+	     (let* ((struct (org-element-property :structure item))
+		    (bul (org-element-property :bullet item))
+		    (num
+		     (number-to-string
+		      (car (last (org-list-get-item-number
+				  (org-element-property :begin item)
+				  struct
+				  (org-list-prevs-alist struct)
+				  (org-list-parents-alist struct)))))))
+	       (replace-regexp-in-string "[0-9]+" num bul)))
+	    (t (let ((bul (org-element-property :bullet item)))
+		 ;; Change bullets into more visible form if UTF-8 is active.
+		 (if (not (eq (plist-get info :ascii-charset) 'utf-8)) bul
+		   (replace-regexp-in-string
+		    "-" "•"
 		    (replace-regexp-in-string
-		     "-" "•"
-		     (replace-regexp-in-string
-		      "+" "⁃"
-		      (replace-regexp-in-string "*" "‣" bul)))))))))))
+		     "+" "⁃"
+		     (replace-regexp-in-string "*" "‣" bul))))))))))
     (concat
      bullet
      ;; Contents: Pay attention to indentation.  Note: check-boxes are
@@ -1432,7 +1430,7 @@ information."
 CONTENTS is the contents of the paragraph, as a string.  INFO is
 the plist used as a communication channel."
   (org-e-ascii--fill-string
-   (let ((parent (car (org-export-get-genealogy paragraph info))))
+   (let ((parent (org-export-get-parent paragraph info)))
      ;; If PARAGRAPH is the first one in a list element, be sure to
      ;; add the check-box in front of it, before any filling.  Later,
      ;; it would interfere with line width.

EXPERIMENTAL/org-e-html.el

@@ -2506,10 +2506,9 @@ CONTENTS holds the contents of the item.  INFO is a plist holding
 contextual information."
   ;; Grab `:level' from plain-list properties, which is always the
   ;; first element above current item.
-  (let* ((plain-list (car (org-export-get-genealogy item info)))
+  (let* ((plain-list (org-export-get-parent item info))
 	 (type (org-element-property :type plain-list))
-	 (level (org-element-property
-		 :level (car (plist-get info :genealogy))))
+	 (level (org-element-property :level plain-list))
 	 (counter (org-element-property :counter item))
 	 (checkbox (org-element-property :checkbox item))
 	 (tag (let ((tag (org-element-property :tag item)))

EXPERIMENTAL/org-e-latex.el

@@ -1233,8 +1233,7 @@ CONTENTS holds the contents of the item.  INFO is a plist holding
 contextual information."
   ;; Grab `:level' from plain-list properties, which is always the
   ;; first element above current item.
-  (let* ((level (org-element-property
-		 :level (car (org-export-get-genealogy item info))))
+  (let* ((level (org-element-property :level (org-export-get-parent item info)))
 	 (counter (let ((count (org-element-property :counter item)))
 		    (and count
 			 (< level 4)

EXPERIMENTAL/org-e-odt.el

@@ -4225,10 +4225,9 @@ CONTENTS holds the contents of the item.  INFO is a plist holding
 contextual information."
   ;; Grab `:level' from plain-list properties, which is always the
   ;; first element above current item.
-  (let* ((plain-list (car (org-export-get-genealogy item info)))
+  (let* ((plain-list (org-export-get-parent item info))
 	 (type (org-element-property :type plain-list))
-	 (level (org-element-property
-		 :level (car (plist-get info :genealogy))))
+	 (level (org-element-property :level plain-list))
 	 (counter (org-element-property :counter item))
 	 (checkbox (org-element-property :checkbox item))
 	 (tag (let ((tag (org-element-property :tag item)))

contrib/lisp/org-export.el

@@ -1519,9 +1519,7 @@ Return transcoded string."
 			 ;; indentation: there is none and it might be
 			 ;; misleading.
 			 (and (not (org-export-get-previous-element blob info))
-			      (let ((parent
-				     (car
-				      (org-export-get-genealogy blob info))))
+			      (let ((parent (org-export-get-parent blob info)))
 				(memq (org-element-type parent)
 				      '(footnote-definition item)))))))
 		   (org-export-data paragraph backend info)))))
@@ -3138,10 +3136,11 @@ affiliated keyword."
 
 ;; Here are various functions to retrieve information about the
 ;; neighbourhood of a given element or object.  Neighbours of interest
-;; are parent headline (`org-export-get-parent-headline'), parent
-;; paragraph (`org-export-get-parent-paragraph'), previous element or
-;; object (`org-export-get-previous-element') and next element or
-;; object (`org-export-get-next-element').
+;; are direct parent (`org-export-get-parent'), parent headline
+;; (`org-export-get-parent-headline'), parent paragraph
+;; (`org-export-get-parent-paragraph'), previous element or object
+;; (`org-export-get-previous-element') and next element or object
+;; (`org-export-get-next-element').
 
 ;; All of these functions are just a specific use of the more generic
 ;; `org-export-get-genealogy', which returns the genealogy relative to
@@ -3164,6 +3163,12 @@ used as a communication channel."
 	     (org-element-contents data)))))
     (catch 'exit (funcall walk-data (plist-get info :parse-tree) nil) nil)))
 
+(defun org-export-get-parent (blob info)
+  "Return BLOB parent or nil.
+BLOB is the element or object considered.  INFO is a plist used
+as a communication channel."
+  (car (org-export-get-genealogy blob info)))
+
 (defun org-export-get-parent-headline (blob info)
   "Return closest parent headline or nil.
 
@@ -3198,7 +3203,7 @@ BLOB is an element or object.  INFO is a plist used as
 a communication channel.
 
 Return previous element or object, a string, or nil."
-  (let ((parent (car (org-export-get-genealogy blob info))))
+  (let ((parent (org-export-get-parent blob info)))
     (cadr (member blob (reverse (org-element-contents parent))))))
 
 (defun org-export-get-next-element (blob info)
@@ -3208,7 +3213,7 @@ BLOB is an element or object.  INFO is a plist used as
 a communication channel.
 
 Return next element or object, a string, or nil."
-  (let ((parent (car (org-export-get-genealogy blob info))))
+  (let ((parent (org-export-get-parent blob info)))
     (cadr (member blob (org-element-contents parent)))))