;;; rst.el --- Mode for viewing and editing reStructuredText-documents  -*- lexical-binding: t -*-

;; Copyright (C) 2003-2022 Free Software Foundation, Inc.

;; Maintainer: Stefan Merten <stefan at merten-home dot de>
;; Author: Stefan Merten <stefan at merten-home dot de>,
;;         Martin Blais <blais@furius.ca>,
;;         David Goodger <goodger@python.org>,
;;         Wei-Wei Guo <wwguocn@gmail.com>

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This package provides major mode rst-mode, which supports documents marked
;; up using the reStructuredText format.  Support includes font locking as well
;; as a lot of convenience functions for editing.  It does this by defining a
;; Emacs major mode: rst-mode (ReST).  This mode is derived from text-mode.
;; This package also contains:
;;
;; - Functions to automatically adjust and cycle the section underline
;;   adornments;
;; - A mode that displays the table of contents and allows you to jump anywhere
;;   from it;
;; - Functions to insert and automatically update a TOC in your source
;;   document;
;; - Function to insert list, processing item bullets and enumerations
;;   automatically;
;; - Font-lock highlighting of most reStructuredText structures;
;; - Indentation and filling according to reStructuredText syntax;
;; - Cursor movement according to reStructuredText syntax;
;; - Some other convenience functions.
;;
;; See the accompanying document in the docutils documentation about
;; the contents of this package and how to use it.
;;
;; For more information about reStructuredText, see
;; https://docutils.sourceforge.io/rst.html
;;
;; For full details on how to use the contents of this file, see
;; https://docutils.sourceforge.io/docs/user/emacs.html
;;
;; There are a number of convenient key bindings provided by rst-mode.  For the
;; bindings, try C-c C-h when in rst-mode.  There are also many variables that
;; can be customized, look for defcustom in this file or look for the "rst"
;; customization group contained in the "wp" group.
;;
;; If you use the table-of-contents feature, you may want to add a hook to
;; update the TOC automatically every time you adjust a section title::
;;
;;   (add-hook 'rst-adjust-hook 'rst-toc-update)
;;
;; Syntax highlighting: font-lock is enabled by default.  If you want to turn
;; off syntax highlighting to rst-mode, you can use the following::
;;
;;   (setq font-lock-global-modes '(not rst-mode ...))
;;

;;; DOWNLOAD

;; The latest release of this file lies in the docutils source code repository:
;;   https://sourceforge.net/p/docutils/code/HEAD/tree/trunk/docutils/tools/editors/emacs/rst.el

;;; INSTALLATION

;; Add the following lines to your init file:
;;
;;   (require 'rst)
;;
;; If you are using `.txt' as a standard extension for reST files as
;; https://docutils.sourceforge.io/FAQ.html#what-s-the-standard-filename-extension-for-a-restructuredtext-file
;; suggests you may use one of the `Local Variables in Files' mechanism Emacs
;; provides to set the major mode automatically.  For instance you may use::
;;
;;    .. -*- mode: rst -*-
;;
;; in the very first line of your file.  The following code is useful if you
;; want automatically enter rst-mode from any file with compatible extensions:
;;
;; (setq auto-mode-alist
;;       (append '(("\\.txt\\'" . rst-mode)
;;                 ("\\.rst\\'" . rst-mode)
;;                 ("\\.rest\\'" . rst-mode)) auto-mode-alist))
;;

;;; Code:

;; FIXME: Check through major mode conventions again.

;; FIXME: Embed complicated `defconst's in `eval-when-compile'.

;; Common Lisp stuff
(require 'cl-lib)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Support for `testcover'

(defun rst-testcover-add-compose (fun)
  "Add FUN to `testcover-compose-functions'."
  (when (boundp 'testcover-compose-functions)
    (add-to-list 'testcover-compose-functions fun)))

(defun rst-testcover-add-1value (fun)
  "Add FUN to `testcover-1value-functions'."
  (when (boundp 'testcover-1value-functions)
    (add-to-list 'testcover-1value-functions fun)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Helpers.

(cl-defmacro rst-destructuring-dolist
    ((arglist list &optional result) &rest body)
  "`cl-dolist' with destructuring of the list elements.
ARGLIST is a Common List argument list which may include
destructuring.  LIST, RESULT and BODY are as for `cl-dolist'.
Note that definitions in ARGLIST are visible only in the BODY and
neither in RESULT nor in LIST."
  ;; FIXME: It would be very useful if the definitions in ARGLIST would be
  ;;        visible in RESULT. But may be this is rather a
  ;;        `rst-destructuring-do' then.
  (declare (debug
	    (&define ([&or symbolp cl-macro-list] def-form &optional def-form)
		     cl-declarations def-body))
           (indent 1))
  (let ((var (make-symbol "--rst-destructuring-dolist-var--")))
  `(cl-dolist (,var ,list ,result)
     (cl-destructuring-bind ,arglist ,var
       ,@body))))

(defun rst-forward-line-strict (n &optional limit)
  ;; testcover: ok.
  "Try to move point to beginning of line I + N where I is the current line.
Return t if movement is successful.  Otherwise don't move point
and return nil.  If a position is given by LIMIT, movement
happened but the following line is missing and thus its beginning
can not be reached but the movement reached at least LIMIT
consider this a successful movement.  LIMIT is ignored in other
cases."
  (let ((start (point)))
    (if (and (zerop (forward-line n))
	     (or (bolp)
		 (and limit
		      (>= (point) limit))))
	t
      (goto-char start)
      nil)))

(defun rst-forward-line-looking-at (n rst-re-args &optional fun)
  ;; testcover: ok.
  "Move forward N lines and if successful check whether RST-RE-ARGS is matched.
Moving forward is done by `rst-forward-line-strict'.  RST-RE-ARGS
is a single or a list of arguments for `rst-re'.  FUN is a
function defaulting to `identity' which is called after the call
to `looking-at' receiving its return value as the first argument.
When FUN is called match data is just set by `looking-at' and
point is at the beginning of the line.  Return nil if moving
forward failed or otherwise the return value of FUN.  Preserve
global match data, point, mark and current buffer."
  (unless (listp rst-re-args)
    (setq rst-re-args (list rst-re-args)))
  (unless fun
    (setq fun #'identity))
  (save-match-data
    (save-excursion
      (when (rst-forward-line-strict n)
	(funcall fun (looking-at (apply #'rst-re rst-re-args)))))))

(rst-testcover-add-1value 'rst-delete-entire-line)
(defun rst-delete-entire-line (n)
  "Move N lines and delete the entire line."
  (delete-region (line-beginning-position (+ n 1))
                 (line-beginning-position (+ n 2))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Versions

(defun rst-extract-version (delim-re head-re re tail-re var &optional default)
  ;; testcover: ok.
  "Extract the version from a variable according to the given regexes.
Return the version after regex DELIM-RE and HEAD-RE matching RE
and before TAIL-RE and DELIM-RE in VAR or DEFAULT for no match."
  (if (string-match
       (concat delim-re head-re "\\(" re "\\)" tail-re delim-re)
       var)
      (match-string 1 var)
    default))

;; Use CVSHeader to really get information from CVS and not other version
;; control systems.
(defconst rst-cvs-header
  "$CVSHeader: sm/rst_el/rst.el,v 1.1058.2.9 2017/01/08 09:54:50 stefan Exp $")
(defconst rst-cvs-rev
  (rst-extract-version "\\$" "CVSHeader: \\S + " "[0-9]+\\(?:\\.[0-9]+\\)+"
		       " .*" rst-cvs-header "0.0")
  "The CVS revision of this file.  CVS revision is the development revision.")
(defconst rst-cvs-timestamp
  (rst-extract-version "\\$" "CVSHeader: \\S + \\S + "
		       "[0-9]+-[0-9]+-[0-9]+ [0-9]+:[0-9]+:[0-9]+" " .*"
		       rst-cvs-header "1970-01-01 00:00:00")
  "The CVS time stamp of this file.")

;; Use LastChanged... to really get information from SVN.
(defconst rst-svn-rev
  (rst-extract-version "\\$" "LastChangedRevision: " "[0-9]+" " "
		       "$LastChangedRevision: 8015 $")
  "The SVN revision of this file.
SVN revision is the upstream (docutils) revision.")
(defconst rst-svn-timestamp
  (rst-extract-version "\\$" "LastChangedDate: " ".+" " "
		       "$LastChangedDate: 2017-01-08 10:54:35 +0100 (Sun, 08 Jan 2017) $")
  "The SVN time stamp of this file.")

;; Maintained by the release process.
(defconst rst-official-version
  (rst-extract-version "%" "OfficialVersion: " "[0-9]+\\(?:\\.[0-9]+\\)+" " "
		       "%OfficialVersion: 1.5.2 %")
  "Official version of the package.")
(defconst rst-official-cvs-rev
  (rst-extract-version "[%$]" "Revision: " "[0-9]+\\(?:\\.[0-9]+\\)+" " "
		       "$Revision: 1.1058.2.9 $")
  "CVS revision of this file in the official version.")

(defconst rst-version
  (if (equal rst-official-cvs-rev rst-cvs-rev)
      rst-official-version
    (format "%s (development %s [%s])" rst-official-version
	    rst-cvs-rev rst-cvs-timestamp))
  "The version string.
Starts with the current official version.  For developer versions
in parentheses follows the development revision and the time stamp.")

(defconst rst-package-emacs-version-alist
  '(("1.0.0" . "24.3")
    ("1.1.0" . "24.3")
    ("1.2.0" . "24.3")
    ("1.2.1" . "24.3")
    ("1.3.0" . "24.3")
    ("1.3.1" . "24.3")
    ("1.4.0" . "24.3")
    ("1.4.1" . "25.1")
    ("1.4.2" . "25.1")
    ("1.5.0" . "26.1")
    ("1.5.1" . "26.1")
    ("1.5.2" . "26.1")
    ;; Whatever the Emacs version is this rst.el version ends up in.
    ))

(unless (assoc rst-official-version rst-package-emacs-version-alist)
  (error "Version %s not listed in `rst-package-emacs-version-alist'"
	 rst-version))

(add-to-list 'customize-package-emacs-version-alist
	     (cons 'ReST rst-package-emacs-version-alist))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Initialize customization

(defgroup rst nil "Support for reStructuredText documents."
  :group 'text
  :version "23.1"
  :link '(url-link "https://docutils.sourceforge.io/rst.html"))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Facilities for regular expressions used everywhere

;; The trailing numbers in the names give the number of referenceable regex
;; groups contained in the regex.

;; Used to be customizable but really is not customizable but fixed by the reST
;; syntax.
(defconst rst-bullets
  ;; Sorted so they can form a character class when concatenated.
  '(?- ?* ?+ ?• ?‣ ?⁃)
  "List of all possible bullet characters for bulleted lists.")

(defconst rst-uri-schemes
  '("acap" "cid" "data" "dav" "fax" "file" "ftp" "gopher" "http" "https" "imap"
    "ldap" "mailto" "mid" "modem" "news" "nfs" "nntp" "pop" "prospero" "rtsp"
    "service" "sip" "tel" "telnet" "tip" "urn" "vemmi" "wais")
  "Supported URI schemes.")

(defconst rst-adornment-chars
  ;; Sorted so they can form a character class when concatenated.
  '(?\]
    ?! ?\" ?# ?$ ?% ?& ?' ?\( ?\) ?* ?+ ?, ?. ?/ ?: ?\; ?< ?= ?> ?? ?@ ?\[ ?\\
    ?^ ?_ ?` ?{ ?| ?} ?~
    ?-)
  "Characters which may be used in adornments for sections and transitions.")

(defconst rst-max-inline-length
  1000
  "Maximum length of inline markup to recognize.")

(defconst rst-re-alist-def
  ;; `*-beg' matches * at the beginning of a line.
  ;; `*-end' matches * at the end of a line.
  ;; `*-prt' matches a part of *.
  ;; `*-tag' matches *.
  ;; `*-sta' matches the start of * which may be followed by respective content.
  ;; `*-pfx' matches the delimiter left of *.
  ;; `*-sfx' matches the delimiter right of *.
  ;; `*-hlp' helper for *.
  ;;
  ;; A trailing number says how many referenceable groups are contained.
  `(

    ;; Horizontal white space (`hws')
    (hws-prt "[\t ]")
    (hws-tag hws-prt "*") ; Optional sequence of horizontal white space.
    (hws-sta hws-prt "+") ; Mandatory sequence of horizontal white space.

    ;; Lines (`lin')
    (lin-beg "^" hws-tag) ; Beginning of a possibly indented line.
    (lin-end hws-tag "$") ; End of a line with optional trailing white space.
    (linemp-tag "^" hws-tag "$") ; Empty line with optional white space.

    ;; Various tags and parts
    (ell-tag "\\.\\.\\.") ; Ellipsis
    (bul-tag ,(concat "[" rst-bullets "]")) ; A bullet.
    (ltr-tag "[a-zA-Z]") ; A letter enumerator tag.
    (num-prt "[0-9]") ; A number enumerator part.
    (num-tag num-prt "+") ; A number enumerator tag.
    (rom-prt "[IVXLCDMivxlcdm]") ; A roman enumerator part.
    (rom-tag rom-prt "+") ; A roman enumerator tag.
    (aut-tag "#") ; An automatic enumerator tag.
    (dcl-tag "::") ; Double colon.

    ;; Block lead in (`bli')
    (bli-sfx (:alt hws-sta "$")) ; Suffix of a block lead-in with *optional*
				 ; immediate content.

    ;; Various starts
    (bul-sta bul-tag bli-sfx) ; Start of a bulleted item.
    (bul-beg lin-beg bul-sta) ; A bullet item at the beginning of a line.

    ;; Explicit markup tag (`exm')
    (exm-tag "\\.\\.")
    (exm-sta exm-tag hws-sta)
    (exm-beg lin-beg exm-sta)

    ;; Counters in enumerations (`cnt')
    (cntany-tag (:alt ltr-tag num-tag rom-tag aut-tag)) ; An arbitrary counter.
    (cntexp-tag (:alt ltr-tag num-tag rom-tag)) ; An arbitrary explicit counter.

    ;; Enumerator (`enm')
    (enmany-tag (:alt
		 (:seq cntany-tag "\\.")
		 (:seq "(?" cntany-tag ")"))) ; An arbitrary enumerator.
    (enmexp-tag (:alt
		 (:seq cntexp-tag "\\.")
		 (:seq "(?" cntexp-tag ")"))) ; An arbitrary explicit
					      ; enumerator.
    (enmaut-tag (:alt
		 (:seq aut-tag "\\.")
		 (:seq "(?" aut-tag ")"))) ; An automatic enumerator.
    (enmany-sta enmany-tag bli-sfx) ; An arbitrary enumerator start.
    (enmexp-sta enmexp-tag bli-sfx) ; An arbitrary explicit enumerator start.
    (enmexp-beg lin-beg enmexp-sta) ; An arbitrary explicit enumerator start
				    ; at the beginning of a line.

    ;; Items may be enumerated or bulleted (`itm')
    (itmany-tag (:alt enmany-tag bul-tag)) ; An arbitrary item tag.
    (itmany-sta-1 (:grp itmany-tag) bli-sfx) ; An arbitrary item start, group
					     ; is the item tag.
    (itmany-beg-1 lin-beg itmany-sta-1) ; An arbitrary item start at the
				        ; beginning of a line, group is the
				        ; item tag.

    ;; Inline markup (`ilm')
    (ilm-pfx (:alt "^" hws-prt "['\"([{<‘“«’/:-]"))
    (ilm-sfx (:alt "$" hws-prt "[]'\")}>’”»/:.,;!?\\-]"))

    ;; Inline markup content (`ilc')
    (ilcsgl-tag "\\S ") ; A single non-white character.
    (ilcast-prt (:alt "[^*\\]" "\\\\.")) ; Part of non-asterisk content.
    (ilcbkq-prt (:alt "[^`\\]" "\\\\.")) ; Part of non-backquote content.
    (ilcbkqdef-prt (:alt "[^`\\\n]" "\\\\.")) ; Part of non-backquote
					      ; definition.
    (ilcbar-prt (:alt "[^|\\]" "\\\\.")) ; Part of non-vertical-bar content.
    (ilcbardef-prt (:alt "[^|\\\n]" "\\\\.")) ; Part of non-vertical-bar
					      ; definition.
    (ilcast-sfx "[^\t *\\]") ; Suffix of non-asterisk content.
    (ilcbkq-sfx "[^\t `\\]") ; Suffix of non-backquote content.
    (ilcbar-sfx "[^\t |\\]") ; Suffix of non-vertical-bar content.
    (ilcrep-hlp ,(format "\\{0,%d\\}" rst-max-inline-length)) ; Repeat count.
    (ilcast-tag (:alt ilcsgl-tag
		      (:seq ilcsgl-tag
			    ilcast-prt ilcrep-hlp
			    ilcast-sfx))) ; Non-asterisk content.
    (ilcbkq-tag (:alt ilcsgl-tag
		      (:seq ilcsgl-tag
			    ilcbkq-prt ilcrep-hlp
			    ilcbkq-sfx))) ; Non-backquote content.
    (ilcbkqdef-tag (:alt ilcsgl-tag
			 (:seq ilcsgl-tag
			       ilcbkqdef-prt ilcrep-hlp
			       ilcbkq-sfx))) ; Non-backquote definition.
    (ilcbar-tag (:alt ilcsgl-tag
		      (:seq ilcsgl-tag
			    ilcbar-prt ilcrep-hlp
			    ilcbar-sfx))) ; Non-vertical-bar content.
    (ilcbardef-tag (:alt ilcsgl-tag
			 (:seq ilcsgl-tag
			       ilcbardef-prt ilcrep-hlp
			       ilcbar-sfx))) ; Non-vertical-bar definition.

    ;; Fields (`fld')
    (fldnam-prt (:alt "[^:\n]" "\\\\:")) ; Part of a field name.
    (fldnam-tag fldnam-prt "+") ; A field name.
    (fld-tag ":" fldnam-tag ":") ; A field marker.

    ;; Options (`opt')
    (optsta-tag (:alt "[+/-]" "--")) ; Start of an option.
    (optnam-tag "\\sw" (:alt "-" "\\sw") "*") ; Name of an option.
    (optarg-tag (:shy "[ =]\\S +")) ; Option argument.
    (optsep-tag (:shy "," hws-prt)) ; Separator between options.
    (opt-tag (:shy optsta-tag optnam-tag optarg-tag "?")) ; A complete option.

    ;; Footnotes and citations (`fnc')
    (fncnam-prt "[^]\n]") ; Part of a footnote or citation name.
    (fncnam-tag fncnam-prt "+") ; A footnote or citation name.
    (fnc-tag "\\[" fncnam-tag "]") ; A complete footnote or citation tag.
    (fncdef-tag-2 (:grp exm-sta)
		  (:grp fnc-tag)) ; A complete footnote or citation definition
				  ; tag.  First group is the explicit markup
				  ; start, second group is the footnote /
				  ; citation tag.
    (fnc-sta-2 fncdef-tag-2 bli-sfx) ; Start of a footnote or citation
				     ; definition.  First group is the explicit
				     ; markup start, second group is the
				     ; footnote / citation tag.

    ;; Substitutions (`sub')
    (sub-tag "|" ilcbar-tag "|") ; A complete substitution tag.
    (subdef-tag "|" ilcbardef-tag "|") ; A complete substitution definition
				       ; tag.

    ;; Symbol (`sym')
    (sym-prt "[+.:_-]") ; Non-word part of a symbol.
    (sym-tag (:shy "\\sw+" (:shy sym-prt "\\sw+") "*"))

    ;; URIs (`uri')
    (uri-tag (:alt ,@rst-uri-schemes))

    ;; Adornment (`ado')
    (ado-prt "[" ,(concat rst-adornment-chars) "]")
    (adorep3-hlp "\\{3,\\}") ; There must be at least 3 characters because
			     ; otherwise explicit markup start would be
			     ; recognized.
    (adorep2-hlp "\\{2,\\}") ; As `adorep3-hlp' but when the first of three
			     ; characters is matched differently.
    (ado-tag-1-1 (:grp ado-prt)
		 "\\1" adorep2-hlp) ; A complete adornment, group is the first
				    ; adornment character and MUST be the FIRST
				    ; group in the whole expression.
    (ado-tag-1-2 (:grp ado-prt)
		 "\\2" adorep2-hlp) ; A complete adornment, group is the first
				    ; adornment character and MUST be the
				    ; SECOND group in the whole expression.
    (ado-beg-2-1 "^" (:grp ado-tag-1-2)
		 lin-end) ; A complete adornment line; first group is the whole
			  ; adornment and MUST be the FIRST group in the whole
			  ; expression; second group is the first adornment
			  ; character.

    ;; Titles (`ttl')
    (ttl-tag "\\S *\\w.*\\S ") ; A title text.
    (ttl-beg-1 lin-beg (:grp ttl-tag)) ; A title text at the beginning of a
				       ; line.  First group is the complete,
				       ; trimmed title text.

    ;; Directives and substitution definitions (`dir')
    (dir-tag-3 (:grp exm-sta)
	       (:grp (:shy subdef-tag hws-sta) "?")
	       (:grp sym-tag dcl-tag)) ; A directive or substitution definition
				       ; tag.  First group is explicit markup
				       ; start, second group is a possibly
				       ; empty substitution tag, third group is
				       ; the directive tag including the double
				       ; colon.
    (dir-sta-3 dir-tag-3 bli-sfx) ; Start of a directive or substitution
				  ; definition.  Groups are as in dir-tag-3.

    ;; Literal block (`lit')
    (lit-sta-2 (:grp (:alt "[^.\n]" "\\.[^.\n]") ".*") "?"
	       (:grp dcl-tag) "$") ; Start of a literal block.  First group is
				   ; any text before the double colon tag which
				   ; may not exist, second group is the double
				   ; colon tag.

    ;; Comments (`cmt')
    (cmt-sta-1 (:grp exm-sta) "[^[|_\n]"
	       (:alt "[^:\n]" (:seq ":" (:alt "[^:\n]" "$")))
	       "*$") ; Start of a comment block; first group is explicit markup
		     ; start.

    ;; Paragraphs (`par')
    (par-tag- (:alt itmany-tag fld-tag opt-tag fncdef-tag-2 dir-tag-3 exm-tag)
	      ) ; Tag at the beginning of a paragraph; there may be groups in
		; certain cases.
    )
  "Definition alist of relevant regexes.
Each entry consists of the symbol naming the regex and an
argument list for `rst-re'.")

(defvar rst-re-alist) ; Forward declare to use it in `rst-re'.

;; FIXME: Use `sregex' or `rx' instead of re-inventing the wheel.
(rst-testcover-add-compose 'rst-re)
(defun rst-re (&rest args)
  ;; testcover: ok.
  "Interpret ARGS as regular expressions and return a regex string.
Each element of ARGS may be one of the following:

A string which is inserted unchanged.

A character which is resolved to a quoted regex.

A symbol which is resolved to a string using `rst-re-alist-def'.

A list with a keyword in the car.  Each element of the cdr of such
a list is recursively interpreted as ARGS.  The results of this
interpretation are concatenated according to the keyword.

For the keyword `:seq' the results are simply concatenated.

For the keyword `:shy' the results are concatenated and
surrounded by a shy-group (\"\\(?:...\\)\").

For the keyword `:alt' the results form an alternative (\"\\|\")
which is shy-grouped (\"\\(?:...\\)\").

For the keyword `:grp' the results are concatenated and form a
referenceable group (\"\\(...\\)\").

After interpretation of ARGS the results are concatenated as for
`:seq'."
  (apply #'concat
	 (mapcar
          (lambda (re)
            (cond
             ((stringp re)
              re)
             ((symbolp re)
              (cadr (assoc re rst-re-alist)))
             ((characterp re)
              (regexp-quote (char-to-string re)))
             ((listp re)
              (let ((nested
                     (mapcar #'rst-re (cdr re))))
                (cond
                 ((eq (car re) :seq)
                  (mapconcat #'identity nested ""))
                 ((eq (car re) :shy)
                  (concat "\\(?:" (mapconcat #'identity nested "") "\\)"))
                 ((eq (car re) :grp)
                  (concat "\\(" (mapconcat #'identity nested "") "\\)"))
                 ((eq (car re) :alt)
                  (concat "\\(?:" (mapconcat #'identity nested "\\|") "\\)"))
                 (t
                  (error "Unknown list car: %s" (car re))))))
             (t
              (error "Unknown object type for building regex: %s" re))))
	  args)))

;; FIXME: Remove circular dependency between `rst-re' and `rst-re-alist'.
(with-no-warnings ; Silence byte-compiler about this construction.
  (defconst rst-re-alist
    ;; Shadow global value we are just defining so we can construct it step by
    ;; step.
    (let (rst-re-alist)
      (dolist (re rst-re-alist-def rst-re-alist)
	(setq rst-re-alist
	      (nconc rst-re-alist
		     (list (list (car re) (apply #'rst-re (cdr re))))))))
    "Alist mapping symbols from `rst-re-alist-def' to regex strings."))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Concepts

;; Each of the following classes represents an own concept. The suffix of the
;; class name is used in the code to represent entities of the respective
;; class.
;;
;; In addition a reStructuredText section header in the buffer is called
;; "section".
;;
;; For lists a "s" is added to the name of the concepts.


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Class rst-Ado

(cl-defstruct
  (rst-Ado
   (:constructor nil) ; Prevent creating unchecked values.
   ;; Construct a transition.
   (:constructor
    rst-Ado-new-transition
    (&aux
     ;; (char nil)
     (-style 'transition)))
   ;; Construct a simple section header.
   (:constructor
    rst-Ado-new-simple
    (char-arg
     &aux
     (char (rst-Ado--validate-char char-arg))
     (-style 'simple)))
   ;; Construct an over-and-under section header.
   (:constructor
    rst-Ado-new-over-and-under
    (char-arg
     &aux
     (char (rst-Ado--validate-char char-arg))
     (-style 'over-and-under)))
   ;; Construct from adornment with inverted style.
   (:constructor
    rst-Ado-new-invert
    (ado-arg
     &aux
     (char (rst-Ado-char ado-arg))
     (-style (let ((sty (rst-Ado--style ado-arg)))
	      (cond
	       ((eq sty 'simple)
		'over-and-under)
	       ((eq sty 'over-and-under)
		'simple)
	       (sty)))))))
  "Representation of a reStructuredText adornment.
Adornments are either section markers where they markup the
section header or transitions.

This type is immutable."
  ;; The character used for the adornment.
  (char nil :read-only t)
  ;; The style of the adornment. This is a private attribute.
  (-style nil :read-only t))

;; Private class methods

(defun rst-Ado--validate-char (char)
  ;; testcover: ok.
  "Validate CHAR to be a valid adornment character.
Return CHAR if so or signal an error otherwise."
  (cl-check-type char character)
  (cl-check-type char (satisfies
		       (lambda (c)
			 (memq c rst-adornment-chars)))
		 "Character must be a valid adornment character")
  char)

;; Public methods

(defun rst-Ado-is-transition (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a transition adornment."
  (cl-check-type self rst-Ado)
  (eq (rst-Ado--style self) 'transition))

(defun rst-Ado-is-section (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a section adornment."
  (cl-check-type self rst-Ado)
  (not (rst-Ado-is-transition self)))

(defun rst-Ado-is-simple (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a simple section adornment."
  (cl-check-type self rst-Ado)
  (eq (rst-Ado--style self) 'simple))

(defun rst-Ado-is-over-and-under (self)
  ;; testcover: ok.
  "Return non-nil if SELF is an over-and-under section adornment."
  (cl-check-type self rst-Ado)
  (eq (rst-Ado--style self) 'over-and-under))

(defun rst-Ado-equal (self other)
  ;; testcover: ok.
  "Return non-nil when SELF and OTHER are equal."
  (cl-check-type self rst-Ado)
  (cl-check-type other rst-Ado)
  (cond
   ((not (eq (rst-Ado--style self) (rst-Ado--style other)))
    nil)
   ((rst-Ado-is-transition self))
   ((equal (rst-Ado-char self) (rst-Ado-char other)))))

(defun rst-Ado-position (self ados)
  ;; testcover: ok.
  "Return position of SELF in ADOS or nil."
  (cl-check-type self rst-Ado)
  (cl-position-if (lambda (e)
                    (rst-Ado-equal self e))
		  ados))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Class rst-Hdr

(cl-defstruct
  (rst-Hdr
   (:constructor nil) ; Prevent creating unchecked values.
   ;; Construct while all parameters must be valid.
   (:constructor
    rst-Hdr-new
    (ado-arg
     indent-arg
     &aux
     (ado (rst-Hdr--validate-ado ado-arg))
     (indent (rst-Hdr--validate-indent indent-arg ado nil))))
   ;; Construct while all parameters but `indent' must be valid.
   (:constructor
    rst-Hdr-new-lax
    (ado-arg
     indent-arg
     &aux
     (ado (rst-Hdr--validate-ado ado-arg))
     (indent (rst-Hdr--validate-indent indent-arg ado t))))
   ;; Construct a header with same characteristics but opposite style as `ado'.
   (:constructor
    rst-Hdr-new-invert
    (ado-arg
     indent-arg
     &aux
     (ado (rst-Hdr--validate-ado (rst-Ado-new-invert ado-arg)))
     (indent (rst-Hdr--validate-indent indent-arg ado t))))
   (:copier nil)) ; Not really needed for an immutable type.
  "Representation of reStructuredText section header characteristics.

This type is immutable."
  ;; The adornment of the header.
  (ado nil :read-only t)
  ;; The indentation of a title text or nil if not given.
  (indent nil :read-only t))

;; Private class methods

(defun rst-Hdr--validate-indent (indent ado lax)
  ;; testcover: ok.
  "Validate INDENT to be a valid indentation for ADO.
Return INDENT if so or signal an error otherwise.  If LAX don't
signal an error and return a valid indent."
  (cl-check-type indent integer)
  (cond
   ((zerop indent)
    indent)
   ((rst-Ado-is-simple ado)
    (if lax
	0
      (signal 'args-out-of-range
	      '("Indentation must be 0 for style simple"))))
   ((< indent 0)
    (if lax
	0
      (signal 'args-out-of-range
	      '("Indentation must not be negative"))))
   ;; Implicitly over-and-under.
   (indent)))

(defun rst-Hdr--validate-ado (ado)
  ;; testcover: ok.
  "Validate ADO to be a valid adornment.
Return ADO if so or signal an error otherwise."
  (cl-check-type ado rst-Ado)
  (cond
   ((rst-Ado-is-transition ado)
    (signal 'args-out-of-range
	    '("Adornment for header must not be transition.")))
   (ado)))

;; Public class methods

(define-obsolete-variable-alias
  'rst-preferred-decorations 'rst-preferred-adornments "rst 1.0.0")

(defvar rst-preferred-adornments) ; Forward declaration.

(defun rst-Hdr-preferred-adornments ()
  ;; testcover: ok.
  "Return preferred adornments as list of `rst-Hdr'."
  (mapcar (cl-function
	   (lambda ((character style indent))
	     (rst-Hdr-new-lax
	      (if (eq style 'over-and-under)
		  (rst-Ado-new-over-and-under character)
		(rst-Ado-new-simple character))
	      indent)))
	  rst-preferred-adornments))

;; Public methods

(defun rst-Hdr-member-ado (self hdrs)
  ;; testcover: ok.
  "Return sublist of HDRS whose car's adornment equals that of SELF or nil."
  (cl-check-type self rst-Hdr)
  (let ((ado (rst-Hdr-ado self)))
    (cl-member-if (lambda (hdr)
                    (rst-Ado-equal ado (rst-Hdr-ado hdr)))
		  hdrs)))

(defun rst-Hdr-ado-map (selves)
  ;; testcover: ok.
  "Return `rst-Ado' list extracted from elements of SELVES."
  (mapcar #'rst-Hdr-ado selves))

(defun rst-Hdr-get-char (self)
  ;; testcover: ok.
  "Return character of the adornment of SELF."
  (cl-check-type self rst-Hdr)
  (rst-Ado-char (rst-Hdr-ado self)))

(defun rst-Hdr-is-over-and-under (self)
  ;; testcover: ok.
  "Return non-nil if SELF is an over-and-under section header."
  (cl-check-type self rst-Hdr)
  (rst-Ado-is-over-and-under (rst-Hdr-ado self)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Class rst-Ttl

(cl-defstruct
  (rst-Ttl
   (:constructor nil) ; Prevent creating unchecked values.
   ;; Construct with valid parameters for all attributes.
   (:constructor ; Private constructor
    rst-Ttl--new
    (ado-arg
     match-arg
     indent-arg
     text-arg
     &aux
     (ado (rst-Ttl--validate-ado ado-arg))
     (match (rst-Ttl--validate-match match-arg ado))
     (indent (rst-Ttl--validate-indent indent-arg ado))
     (text (rst-Ttl--validate-text text-arg ado))
     (hdr (condition-case nil
	      (rst-Hdr-new ado indent)
	    (error nil)))))
   (:copier nil)) ; Not really needed for an immutable type.
  "Representation of a reStructuredText section header as found in a buffer.
This type gathers information about an adorned part in the buffer.

This type is immutable."
  ;; The adornment characteristics or nil for a title candidate.
  (ado nil :read-only t)
  ;; The match-data for `ado' in a form similarly returned by `match-data' (but
  ;; not necessarily with markers in buffers). Match group 0 matches the whole
  ;; construct.  Match group 1 matches the overline adornment if present.
  ;; Match group 2 matches the section title text or the transition.  Match
  ;; group 3 matches the underline adornment.
  (match nil :read-only t)
  ;; An indentation found for the title line or nil for a transition.
  (indent nil :read-only t)
  ;; The text of the title or nil for a transition.
  (text nil :read-only t)
  ;; The header characteristics if it is a valid section header.
  (hdr nil :read-only t)
  ;; FIXME refactoring: Should have an attribute `buffer' for the buffer this
  ;;                    title is found in.  This breaks lots and lots of tests.
  ;;                    However, with private constructor they may not be
  ;;                    necessary any more.  In case it is really a buffer then
  ;;                    also `match' could be real data from `match-data' which
  ;;                    contains markers instead of integers.
  )

;; Private class methods

(defun rst-Ttl--validate-ado (ado)
  ;; testcover: ok.
  "Return valid ADO or signal error."
  (cl-check-type ado (or null rst-Ado))
  ado)

(defun rst-Ttl--validate-match (match ado)
  ;; testcover: ok.
  "Return valid MATCH matching ADO or signal error."
  (cl-check-type ado (or null rst-Ado))
  (cl-check-type match list)
  (cl-check-type match (satisfies (lambda (m)
				    (equal (length m) 8)))
		 "Match data must consist of exactly 8 buffer positions.")
  (dolist (pos match)
    (cl-check-type pos (or null integer-or-marker)))
  (cl-destructuring-bind (all-beg all-end
			  ovr-beg ovr-end
			  txt-beg txt-end
			  und-beg und-end) match
    (unless (and (integer-or-marker-p all-beg) (integer-or-marker-p all-end))
      (signal 'args-out-of-range
	      '("First two elements of match data must be buffer positions.")))
    (cond
     ((null ado)
      (unless (and (null ovr-beg) (null ovr-end)
		   (integer-or-marker-p txt-beg) (integer-or-marker-p txt-end)
		   (null und-beg) (null und-end))
	(signal 'args-out-of-range
		'("For a title candidate exactly the third match pair must be set."))))
     ((rst-Ado-is-transition ado)
      (unless (and (null ovr-beg) (null ovr-end)
		   (integer-or-marker-p txt-beg) (integer-or-marker-p txt-end)
		   (null und-beg) (null und-end))
	(signal 'args-out-of-range
		'("For a transition exactly the third match pair must be set."))))
     ((rst-Ado-is-simple ado)
      (unless (and (null ovr-beg) (null ovr-end)
		   (integer-or-marker-p txt-beg) (integer-or-marker-p txt-end)
		   (integer-or-marker-p und-beg) (integer-or-marker-p und-end))
	(signal 'args-out-of-range
		'("For a simple section adornment exactly the third and fourth match pair must be set."))))
     (t ; over-and-under
      (unless (and (integer-or-marker-p ovr-beg) (integer-or-marker-p ovr-end)
		   (integer-or-marker-p txt-beg) (integer-or-marker-p txt-end)
		   (or (null und-beg) (integer-or-marker-p und-beg))
		   (or (null und-end) (integer-or-marker-p und-end)))
	(signal 'args-out-of-range
		'("For an over-and-under section adornment all match pairs must be set."))))))
  match)

(defun rst-Ttl--validate-indent (indent ado)
  ;; testcover: ok.
  "Return valid INDENT for ADO or signal error."
  (if (and ado (rst-Ado-is-transition ado))
      (cl-check-type indent null
		     "Indent for a transition must be nil.")
    (cl-check-type indent (integer 0 *)
		   "Indent for a section header must be non-negative."))
  indent)

(defun rst-Ttl--validate-text (text ado)
  ;; testcover: ok.
  "Return valid TEXT for ADO or signal error."
  (if (and ado (rst-Ado-is-transition ado))
      (cl-check-type text null
		     "Transitions may not have title text.")
    (cl-check-type text string))
  text)

;; Public class methods

(defun rst-Ttl-from-buffer (ado beg-ovr beg-txt beg-und txt)
  ;; testcover: ok.
  "Return a `rst-Ttl' constructed from information in the current buffer.
ADO is the adornment or nil for a title candidate.  BEG-OVR and
BEG-UND are the starting points of the overline or underline,
respectively.  They may be nil if the respective thing is missing.
BEG-TXT is the beginning of the title line or the transition and
must be given.  The end of the line is used as the end point.  TXT
is the title text or nil.  If TXT is given the indentation of the
line containing BEG-TXT is used as indentation.  Match group 0 is
derived from the remaining information."
  (cl-check-type beg-txt integer-or-marker)
  (save-excursion
    (let ((end-ovr (when beg-ovr
		     (goto-char beg-ovr)
		     (line-end-position)))
	  (end-txt (progn
		     (goto-char beg-txt)
		     (line-end-position)))
	  (end-und (when beg-und
		     (goto-char beg-und)
		     (line-end-position)))
	  (ind (when txt
		 (goto-char beg-txt)
		 (current-indentation))))
      (rst-Ttl--new ado
		    (list
		     (or beg-ovr beg-txt) (or end-und end-txt)
		     beg-ovr end-ovr
		     beg-txt end-txt
		     beg-und end-und)
		    ind txt))))

;; Public methods

(defun rst-Ttl-get-title-beginning (self)
  ;; testcover: ok.
  "Return position of beginning of title text of SELF.
This position should always be at the start of a line."
  (cl-check-type self rst-Ttl)
  (nth 4 (rst-Ttl-match self)))

(defun rst-Ttl-get-beginning (self)
  ;; testcover: ok.
  "Return position of beginning of whole SELF."
  (cl-check-type self rst-Ttl)
  (nth 0 (rst-Ttl-match self)))

(defun rst-Ttl-get-end (self)
  ;; testcover: ok.
  "Return position of end of whole SELF."
  (cl-check-type self rst-Ttl)
  (nth 1 (rst-Ttl-match self)))

(defun rst-Ttl-is-section (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a section header or candidate."
  (cl-check-type self rst-Ttl)
  (rst-Ttl-text self))

(defun rst-Ttl-is-candidate (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a candidate for a section header."
  (cl-check-type self rst-Ttl)
  (not (rst-Ttl-ado self)))

(defun rst-Ttl-contains (self position)
  "Return whether SELF contain POSITION.
Return 0 if SELF contains POSITION, < 0 if SELF ends before
POSITION and > 0 if SELF starts after position."
  (cl-check-type self rst-Ttl)
  (cl-check-type position integer-or-marker)
  (cond
   ((< (nth 1 (rst-Ttl-match self)) position)
    -1)
   ((> (nth 0 (rst-Ttl-match self)) position)
    +1)
   (0)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Class rst-Stn

(cl-defstruct
  (rst-Stn
   (:constructor nil) ; Prevent creating unchecked values.
   ;; Construct while all parameters must be valid.
   (:constructor
    rst-Stn-new
    (ttl-arg
     level-arg
     children-arg
     &aux
     (ttl (rst-Stn--validate-ttl ttl-arg))
     (level (rst-Stn--validate-level level-arg ttl))
     (children (rst-Stn--validate-children children-arg ttl)))))
  "Representation of a section tree node.

This type is immutable."
  ;; The title of the node or nil for a missing node.
  (ttl nil :read-only t)
  ;; The level of the node in the tree. Negative for the (virtual) top level
  ;; node.
  (level nil :read-only t)
  ;; The list of children of the node.
  (children nil :read-only t))
;; FIXME refactoring: Should have an attribute `buffer' for the buffer this
;;                    title is found in. Or use `rst-Ttl-buffer'.

;; Private class methods

(defun rst-Stn--validate-ttl (ttl)
  ;; testcover: ok.
  "Return valid TTL or signal error."
  (cl-check-type ttl (or null rst-Ttl))
  ttl)

(defun rst-Stn--validate-level (level ttl)
  ;; testcover: ok.
  "Return valid LEVEL for TTL or signal error."
  (cl-check-type level integer)
  (when (and ttl (< level 0))
    ;; testcover: Never reached because a title may not have a negative level
    (signal 'args-out-of-range
	    '("Top level node must not have a title.")))
  level)

(defun rst-Stn--validate-children (children ttl)
  ;; testcover: ok.
  "Return valid CHILDREN for TTL or signal error."
  (cl-check-type children list)
  (dolist (child children)
    (cl-check-type child rst-Stn))
  (unless (or ttl children)
    (signal 'args-out-of-range
	    '("A missing node must have children.")))
  children)

;; Public methods

(defun rst-Stn-get-title-beginning (self)
  ;; testcover: ok.
  "Return the beginning of the title of SELF.
Handles missing node properly."
  (cl-check-type self rst-Stn)
  (let ((ttl (rst-Stn-ttl self)))
    (if ttl
	(rst-Ttl-get-title-beginning ttl)
      (rst-Stn-get-title-beginning (car (rst-Stn-children self))))))

(defun rst-Stn-get-text (self &optional default)
  ;; testcover: ok.
  "Return title text of SELF or DEFAULT if SELF is a missing node.
For a missing node and no DEFAULT given return a standard title text."
  (cl-check-type self rst-Stn)
  (let ((ttl (rst-Stn-ttl self)))
    (cond
     (ttl
      (rst-Ttl-text ttl))
     (default)
     ("[missing node]"))))

(defun rst-Stn-is-top (self)
  ;; testcover: ok.
  "Return non-nil if SELF is a top level node."
  (cl-check-type self rst-Stn)
  (< (rst-Stn-level self) 0))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Mode definition

(defun rst-define-key (keymap key def &rest deprecated)
  ;; testcover: ok.
  "Bind like `define-key' but add deprecated key definitions.
KEYMAP, KEY, and DEF are as in `define-key'.  DEPRECATED key
definitions should be in vector notation.  These are defined
as well but give an additional message."
  (define-key keymap key def)
  (when deprecated
    (let* ((command-name (symbol-name def))
           (forwarder-function-name
            (if (string-match "^rst-\\(.*\\)$" command-name)
                (concat "rst-deprecated-"
                        (match-string 1 command-name))
              (error "Not an RST command: %s" command-name)))
           (forwarder-function (intern forwarder-function-name)))
      (unless (fboundp forwarder-function)
        (defalias forwarder-function
          (lambda ()
            (interactive)
            (call-interactively def)
            (message "[Deprecated use of key %s; use key %s instead]"
                     (key-description (this-command-keys))
                     (key-description key)))
          ;; FIXME: In Emacs-25 we could use (:documentation ...) instead.
          (format "Deprecated binding for %s, use \\[%s] instead."
                  def def)))
      (dolist (dep-key deprecated)
        (define-key keymap dep-key forwarder-function)))))

 ;; Key bindings.
(defvar rst-mode-map
  (let ((map (make-sparse-keymap)))

    ;; \C-c is the general keymap.
    (rst-define-key map [?\C-c ?\C-h] #'describe-prefix-bindings)

    ;;
    ;; Section Adornments
    ;;
    ;; The adjustment function that adorns or rotates a section title.
    (rst-define-key map [?\C-c ?\C-=] #'rst-adjust [?\C-c ?\C-a t])
    (rst-define-key map [?\C-=] #'rst-adjust) ; Does not work on macOS and
					      ; on consoles.

    ;; \C-c \C-a is the keymap for adornments.
    (rst-define-key map [?\C-c ?\C-a ?\C-h] #'describe-prefix-bindings)
    ;; Another binding which works with all types of input.
    (rst-define-key map [?\C-c ?\C-a ?\C-a] #'rst-adjust)
    ;; Display the hierarchy of adornments implied by the current document
    ;; contents.
    (rst-define-key map [?\C-c ?\C-a ?\C-d] #'rst-display-hdr-hierarchy)
    ;; Homogenize the adornments in the document.
    (rst-define-key map [?\C-c ?\C-a ?\C-s] #'rst-straighten-sections
		    [?\C-c ?\C-s])

    ;;
    ;; Section Movement and Selection
    ;;
    ;; Mark the subsection where the cursor is.
    (rst-define-key map [?\C-\M-h] #'rst-mark-section
		    ;; Same as mark-defun sgml-mark-current-element.
		    [?\C-c ?\C-m])
    ;; Move backward/forward between section titles.
    ;; FIXME: Also bind similar to outline mode.
    (rst-define-key map [?\C-\M-a] #'rst-backward-section
		    ;; Same as beginning-of-defun.
		    [?\C-c ?\C-n])
    (rst-define-key map [?\C-\M-e] #'rst-forward-section
		    ;; Same as end-of-defun.
		    [?\C-c ?\C-p])

    ;;
    ;; Operating on regions
    ;;
    ;; \C-c \C-r is the keymap for regions.
    (rst-define-key map [?\C-c ?\C-r ?\C-h] #'describe-prefix-bindings)
    ;; Makes region a line-block.
    (rst-define-key map [?\C-c ?\C-r ?\C-l] #'rst-line-block-region
		    [?\C-c ?\C-d])
    ;; Shift region left or right according to tabs.
    (rst-define-key map [?\C-c ?\C-r tab] #'rst-shift-region
		    [?\C-c ?\C-r t] [?\C-c ?\C-l t])

    ;;
    ;; Operating on lists
    ;;
    ;; \C-c \C-l is the keymap for lists.
    (rst-define-key map [?\C-c ?\C-l ?\C-h] #'describe-prefix-bindings)
    ;; Makes paragraphs in region as a bullet list.
    (rst-define-key map [?\C-c ?\C-l ?\C-b] #'rst-bullet-list-region
		    [?\C-c ?\C-b])
    ;; Makes paragraphs in region an enumeration.
    (rst-define-key map [?\C-c ?\C-l ?\C-e] #'rst-enumerate-region
		    [?\C-c ?\C-e])
    ;; Converts bullets to an enumeration.
    (rst-define-key map [?\C-c ?\C-l ?\C-c] #'rst-convert-bullets-to-enumeration
		    [?\C-c ?\C-v])
    ;; Make sure that all the bullets in the region are consistent.
    (rst-define-key map [?\C-c ?\C-l ?\C-s] #'rst-straighten-bullets-region
		    [?\C-c ?\C-w])
    ;; Insert a list item.
    (rst-define-key map [?\C-c ?\C-l ?\C-i] #'rst-insert-list)

    ;;
    ;; Table-of-Contents Features
    ;;
    ;; \C-c \C-t is the keymap for table of contents.
    (rst-define-key map [?\C-c ?\C-t ?\C-h] #'describe-prefix-bindings)
    ;; Enter a TOC buffer to view and move to a specific section.
    (rst-define-key map [?\C-c ?\C-t ?\C-t] #'rst-toc)
    ;; Insert a TOC here.
    (rst-define-key map [?\C-c ?\C-t ?\C-i] #'rst-toc-insert
		    [?\C-c ?\C-i])
    ;; Update the document's TOC (without changing the cursor position).
    (rst-define-key map [?\C-c ?\C-t ?\C-u] #'rst-toc-update
		    [?\C-c ?\C-u])
    ;; Go to the section under the cursor (cursor must be in internal TOC).
    (rst-define-key map [?\C-c ?\C-t ?\C-j] #'rst-toc-follow-link
		    [?\C-c ?\C-f])

    ;;
    ;; Converting Documents from Emacs
    ;;
    ;; \C-c \C-c is the keymap for compilation.
    (rst-define-key map [?\C-c ?\C-c ?\C-h] #'describe-prefix-bindings)
    ;; Run one of two pre-configured toolset commands on the document.
    (rst-define-key map [?\C-c ?\C-c ?\C-c] #'rst-compile
		    [?\C-c ?1])
    (rst-define-key map [?\C-c ?\C-c ?\C-a] #'rst-compile-alt-toolset
		    [?\C-c ?2])
    ;; Convert the active region to pseudo-xml using the docutils tools.
    (rst-define-key map [?\C-c ?\C-c ?\C-x] #'rst-compile-pseudo-region
		    [?\C-c ?3])
    ;; Convert the current document to PDF and launch a viewer on the results.
    (rst-define-key map [?\C-c ?\C-c ?\C-p] #'rst-compile-pdf-preview
		    [?\C-c ?4])
    ;; Convert the current document to S5 slides and view in a web browser.
    (rst-define-key map [?\C-c ?\C-c ?\C-s] #'rst-compile-slides-preview
		    [?\C-c ?5])

    map)
  "Keymap for reStructuredText mode commands.
This inherits from Text mode.")


;; Abbrevs.
(define-abbrev-table 'rst-mode-abbrev-table
  (mapcar (lambda (x)
            (append x '(nil 0 system)))
          '(("contents" ".. contents::\n..\n   ")
            ("con" ".. contents::\n..\n   ")
            ("cont" "[...]")
            ("skip" "\n\n[...]\n\n  ")
            ("seq" "\n\n[...]\n\n  ")
            ;; FIXME: Add footnotes, links, and more.
            ))
  "Abbrev table used while in `rst-mode'.")


;; Syntax table.
(defvar rst-mode-syntax-table
  (let ((st (copy-syntax-table text-mode-syntax-table)))
    (modify-syntax-entry ?$ "." st)
    (modify-syntax-entry ?% "." st)
    (modify-syntax-entry ?& "." st)
    (modify-syntax-entry ?' "." st)
    (modify-syntax-entry ?` "\"`  " st)
    (modify-syntax-entry ?* "\"*  " st)
    (modify-syntax-entry ?+ "." st)
    (modify-syntax-entry ?- "." st)
    (modify-syntax-entry ?/ "." st)
    (modify-syntax-entry ?< "." st)
    (modify-syntax-entry ?= "." st)
    (modify-syntax-entry ?> "." st)
    (modify-syntax-entry ?\\ "\\" st)
    (modify-syntax-entry ?_ "." st)
    (modify-syntax-entry ?| "." st)
    (modify-syntax-entry ?« "." st)
    (modify-syntax-entry ?» "." st)
    (modify-syntax-entry ?‘ "." st)
    (modify-syntax-entry ?’ "." st)
    (modify-syntax-entry ?“ "." st)
    (modify-syntax-entry ?” "." st)
    st)
  "Syntax table used while in `rst-mode'.")

(defcustom rst-mode-hook nil
  "Hook run when `rst-mode' is turned on.
The hook for `text-mode' is run before this one."
  :group 'rst
  :type '(hook))

;; Pull in variable definitions silencing byte-compiler.
(require 'newcomment)

(defvar electric-indent-inhibit)

;; Use rst-mode for *.rst and *.rest files.  Many ReStructured-Text files
;; use *.txt, but this is too generic to be set as a default.
;;;###autoload (add-to-list 'auto-mode-alist (purecopy '("\\.re?st\\'" . rst-mode)))
;;;###autoload
(define-derived-mode rst-mode text-mode "ReST"
  "Major mode for editing reStructuredText documents.
\\<rst-mode-map>

Turning on `rst-mode' calls the normal hooks `text-mode-hook'
and `rst-mode-hook'.  This mode also supports font-lock
highlighting.

\\{rst-mode-map}"
  :abbrev-table rst-mode-abbrev-table
  :syntax-table rst-mode-syntax-table
  :group 'rst

  ;; Paragraph recognition.
  (setq-local paragraph-separate
	      (rst-re '(:alt
			"\f"
			lin-end)))
  (setq-local paragraph-start
	      (rst-re '(:alt
			"\f"
			lin-end
			(:seq hws-tag par-tag- bli-sfx))))

  ;; Indenting and filling.
  (setq-local indent-line-function #'rst-indent-line)
  (setq-local adaptive-fill-mode t)
  (setq-local adaptive-fill-regexp (rst-re 'hws-tag 'par-tag- "?" 'hws-tag))
  (setq-local adaptive-fill-function #'rst-adaptive-fill)
  (setq-local fill-paragraph-handle-comment nil)

  ;; Comments.
  (setq-local comment-start ".. ")
  (setq-local comment-start-skip (rst-re 'lin-beg 'exm-tag 'bli-sfx))
  (setq-local comment-continue "   ")
  (setq-local comment-multi-line t)
  (setq-local comment-use-syntax nil)
  ;; reStructuredText has not really a comment ender but nil is not really a
  ;; permissible value.
  (setq-local comment-end "")
  (setq-local comment-end-skip nil)

  ;; Commenting in reStructuredText is very special so use our own set of
  ;; functions.
  (setq-local comment-line-break-function #'rst-comment-line-break)
  (setq-local comment-indent-function #'rst-comment-indent)
  (setq-local comment-insert-comment-function #'rst-comment-insert-comment)
  (setq-local comment-region-function #'rst-comment-region)
  (setq-local uncomment-region-function #'rst-uncomment-region)

  ;; Imenu and which function.
  ;; FIXME: Check documentation of `which-function' for alternative ways to
  ;;        determine the current function name.
  (setq-local imenu-create-index-function #'rst-imenu-create-index)

  ;; Font lock.
  (setq-local font-lock-defaults
	      '(rst-font-lock-keywords
		t nil nil nil
		(font-lock-multiline . t)
		(font-lock-mark-block-function . mark-paragraph)))
  (add-hook 'font-lock-extend-region-functions
            #'rst-font-lock-extend-region nil t)

  ;; Text after a changed line may need new fontification.
  (setq-local jit-lock-contextually t)

  ;; Indentation is not deterministic.
  (setq-local electric-indent-inhibit t))

;;;###autoload
(define-minor-mode rst-minor-mode
  "Toggle ReST minor mode.

When ReST minor mode is enabled, the ReST mode keybindings
are installed on top of the major mode bindings.  Use this
for modes derived from Text mode, like Mail mode."
  ;; The indicator for the mode line.
  :lighter " ReST"
  ;; The minor mode bindings.
  :keymap rst-mode-map
  :group 'rst)

;; FIXME: can I somehow install these too?
;;        :abbrev-table rst-mode-abbrev-table
;;        :syntax-table rst-mode-syntax-table


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Section adornment adjustment

;; The following functions implement a smart automatic title sectioning feature.
;; The idea is that with the cursor sitting on a section title, we try to get as
;; much information from context and try to do the best thing automatically.
;; This function can be invoked many times and/or with prefix argument to rotate
;; between the various sectioning adornments.
;;
;; Some notes:
;;
;; - The underlining character that is used depends on context. The file is
;;   scanned to find other sections and an appropriate character is selected.
;;   If the function is invoked on a section that is complete, the character is
;;   rotated among the existing section adornments.
;;
;;   Note that when rotating the characters, if we come to the end of the
;;   hierarchy of adornments, the variable `rst-preferred-adornments' is
;;   consulted to propose a new underline adornment, and if continued, we cycle
;;   the adornments all over again.  Set this variable to nil if you want to
;;   limit the underlining character propositions to the existing adornments in
;;   the file.
;;
;; - An underline/overline that is not extended to the column at which it should
;;   be hanging is dubbed INCOMPLETE.  For example::
;;
;;      |Some Title
;;      |-------
;;
;; Examples of default invocation:
;;
;;   |Some Title       --->    |Some Title
;;   |                         |----------
;;
;;   |Some Title       --->    |Some Title
;;   |-----                    |----------
;;
;;   |                         |------------
;;   | Some Title      --->    | Some Title
;;   |                         |------------
;;
;; In over-and-under style, when alternating the style, a variable is
;; available to select how much default indent to use (it can be zero).  Note
;; that if the current section adornment already has an indent, we don't
;; adjust it to the default, we rather use the current indent that is already
;; there for adjustment (unless we cycle, in which case we use the indent
;; that has been found previously).

(defgroup rst-adjust nil
  "Settings for adjustment and cycling of section title adornments."
  :group 'rst
  :version "21.1")

;; FIXME: Default must match suggestion in
;;        http://sphinx-doc.org/rest.html#sections for Python documentation.
(defcustom rst-preferred-adornments '((?= over-and-under 1)
				      (?= simple 0)
				      (?- simple 0)
				      (?~ simple 0)
				      (?+ simple 0)
				      (?` simple 0)
				      (?# simple 0)
				      (?@ simple 0))
  "Preferred hierarchy of section title adornments.
A list consisting of lists of the form (CHARACTER STYLE INDENT).
CHARACTER is the character used.  STYLE is one of the symbols
`over-and-under' or `simple'.  INDENT is an integer giving the
wanted indentation for STYLE `over-and-under'.

This sequence is consulted to offer a new adornment suggestion
when we rotate the underlines at the end of the existing
hierarchy of characters, or when there is no existing section
title in the file.

Set this to an empty list to use only the adornment found in the
file."
  :group 'rst-adjust
  :type `(repeat
	  (group :tag "Adornment specification"
		 (choice :tag "Adornment character"
                         ,@(mapcar (lambda (char)
                                     (list 'const
                                           :tag (char-to-string char) char))
				   rst-adornment-chars))
		 (radio :tag "Adornment type"
			(const :tag "Overline and underline" over-and-under)
			(const :tag "Underline only" simple))
		 (integer :tag "Indentation for overline and underline type"
			  :value 0))))

;; FIXME: Rename this to `rst-over-and-under-default-indent' and set default to
;;        0 because the effect of 1 is probably surprising in the few cases
;;        where this is used.
;; FIXME: A matching adornment style can be looked for in
;;        `rst-preferred-adornments' and its indentation used before using this
;;        variable.
(defcustom rst-default-indent 1
  "Number of characters to indent the section title.
This is only used while toggling adornment styles when switching
from a simple adornment style to an over-and-under adornment
style.  In addition this is used in cases where the adornments
found in the buffer are to be used but the indentation for
over-and-under adornments is inconsistent across the buffer."
  :group 'rst-adjust
  :type '(integer))

(defun rst-new-preferred-hdr (seen prev)
  ;; testcover: ok.
  "Return a new, preferred `rst-Hdr' different from all in SEEN.
PREV is the previous `rst-Hdr' in the buffer.  If given the
search starts after this entry.  Return nil if no new preferred
`rst-Hdr' can be found."
  ;; All preferred adornments are candidates.
  (let ((candidates
	 (append
	  (if prev
	      ;; Start searching after the level of the previous adornment.
	      (cdr (rst-Hdr-member-ado prev (rst-Hdr-preferred-adornments))))
	  (rst-Hdr-preferred-adornments))))
    (cl-find-if (lambda (cand)
                  (not (rst-Hdr-member-ado cand seen)))
		candidates)))

(defun rst-update-section (hdr)
  ;; testcover: ok.
  "Unconditionally update the style of the section header at point to HDR.
If there are existing overline and/or underline from the
existing adornment, they are removed before adding the
requested adornment."
  (end-of-line)
  (let ((indent (or (rst-Hdr-indent hdr) 0))
	(marker (point-marker))
	new)

    ;; Fixup whitespace at the beginning and end of the line.
    (1value
     (rst-forward-line-strict 0))
    (delete-horizontal-space)
    (insert (make-string indent ? ))
    (end-of-line)
    (delete-horizontal-space)
    (setq new (make-string (+ (current-column) indent) (rst-Hdr-get-char hdr)))

    ;; Remove previous line if it is an adornment.
    ;; FIXME refactoring: Check whether this deletes `hdr' which *has* all the
    ;;                    data necessary.
    (when (and (rst-forward-line-looking-at -1 'ado-beg-2-1)
	       ;; Avoid removing the underline of a title right above us.
	       (not (rst-forward-line-looking-at -2 'ttl-beg-1)))
      (rst-delete-entire-line -1))

    ;; Remove following line if it is an adornment.
    (when (rst-forward-line-looking-at +1 'ado-beg-2-1)
      (rst-delete-entire-line +1))

    ;; Insert underline.
    (unless (rst-forward-line-strict +1)
      ;; Normalize buffer by adding final newline.
      (newline 1))
    (open-line 1)
    (insert new)

    ;; Insert overline.
    (when (rst-Hdr-is-over-and-under hdr)
      (1value ; Underline inserted above.
       (rst-forward-line-strict -1))
      (open-line 1)
      (insert new))

    (goto-char marker)))

(defun rst-classify-adornment (adornment end &optional accept-over-only)
  ;; testcover: ok.
  "Classify adornment string for section titles and transitions.
ADORNMENT is the complete adornment string as found in the buffer
with optional trailing whitespace.  END is the point after the
last character of ADORNMENT.  Return a `rst-Ttl' or nil if no
syntactically valid adornment is found.  If ACCEPT-OVER-ONLY an
overline with a missing underline is accepted as valid and
returned."
  (save-excursion
    (save-match-data
      (when (string-match (rst-re 'ado-beg-2-1) adornment)
	(goto-char end)
	(let* ((ado-ch (string-to-char (match-string 2 adornment)))
	       (ado-re (rst-re ado-ch 'adorep3-hlp)) ; RE matching the
						     ; adornment.
	       (beg-pnt (progn
			  (1value
			   (rst-forward-line-strict 0))
			  (point)))
	       (nxt-emp ; Next line nonexistent or empty
		(not (rst-forward-line-looking-at +1 'lin-end #'not)))
	       (prv-emp ; Previous line nonexistent or empty
		(not (rst-forward-line-looking-at -1 'lin-end #'not)))
	       txt-blw
	       (ttl-blw ; Title found below starting here.
		(rst-forward-line-looking-at
		 +1 'ttl-beg-1
                 (lambda (mtcd)
                   (when mtcd
                     (setq txt-blw (match-string-no-properties 1))
                     (point)))))
	       txt-abv
	       (ttl-abv ; Title found above starting here.
		(rst-forward-line-looking-at
		  -1 'ttl-beg-1
                  (lambda (mtcd)
                    (when mtcd
                      (setq txt-abv (match-string-no-properties 1))
                      (point)))))
	       (und-fnd ; Matching underline found starting here.
		(and ttl-blw
		     (rst-forward-line-looking-at
		      +2 (list ado-re 'lin-end)
                      (lambda (mtcd)
                        (when mtcd
                          (point))))))
	       (ovr-fnd ; Matching overline found starting here.
		(and ttl-abv
		     (rst-forward-line-looking-at
		      -2 (list ado-re 'lin-end)
                      (lambda (mtcd)
                        (when mtcd
                          (point))))))
	       (und-wng ; Wrong underline found starting here.
		(and ttl-blw
		     (not und-fnd)
		     (rst-forward-line-looking-at
		      +2 'ado-beg-2-1
                      (lambda (mtcd)
                        (when mtcd
                          (point))))))
	       (ovr-wng ; Wrong overline found starting here.
		(and ttl-abv (not ovr-fnd)
		     (rst-forward-line-looking-at
		       -2 'ado-beg-2-1
                       (lambda (mtcd)
                         (when (and
                                mtcd
                                ;; An adornment above may be a legal
                                ;; adornment for the line above - consider it
                                ;; a wrong overline only when it is equally
                                ;; long.
                                (equal
                                 (length (match-string-no-properties 1))
                                 (length adornment)))
                           (point)))))))
	  (cond
	   ((and nxt-emp prv-emp)
	    ;; A transition.
	    (rst-Ttl-from-buffer (rst-Ado-new-transition)
				 nil beg-pnt nil nil))
	   (ovr-fnd ; Prefer overline match over underline match.
	    ;; An overline with an underline.
	    (rst-Ttl-from-buffer (rst-Ado-new-over-and-under ado-ch)
				 ovr-fnd ttl-abv beg-pnt txt-abv))
	   (und-fnd
	    ;; An overline with an underline.
	    (rst-Ttl-from-buffer (rst-Ado-new-over-and-under ado-ch)
				 beg-pnt ttl-blw und-fnd txt-blw))
	   ((and ttl-abv (not ovr-wng))
	    ;; An underline.
	    (rst-Ttl-from-buffer (rst-Ado-new-simple ado-ch)
				 nil ttl-abv beg-pnt txt-abv))
	   ((and accept-over-only ttl-blw (not und-wng))
	    ;; An overline with a missing underline.
	    (rst-Ttl-from-buffer (rst-Ado-new-over-and-under ado-ch)
				 beg-pnt ttl-blw nil txt-blw))
	   (t
	    ;; Invalid adornment.
	    nil)))))))

(defun rst-ttl-at-point ()
  ;; testcover: ok.
  "Find a section title line around point and return its characteristics.
If the point is on an adornment line find the respective title
line.  If the point is on an empty line check previous or next
line whether it is a suitable title line and use it if so.  If
point is on a suitable title line use it.  Return a `rst-Ttl' for
a section header or nil if no title line is found."
  (save-excursion
    (save-match-data
      (1value
       (rst-forward-line-strict 0))
      (let* (cnd-beg ; Beginning of a title candidate.
	     cnd-txt ; Text of a title candidate.
             (cnd-fun (lambda (mtcd) ; Function setting title candidate data.
                        (when mtcd
                          (setq cnd-beg (match-beginning 0))
                          (setq cnd-txt (match-string-no-properties 1))
                          t)))
	     ttl)
	(cond
	 ((looking-at (rst-re 'ado-beg-2-1))
	  ;; Adornment found - consider it.
	  (setq ttl (rst-classify-adornment (match-string-no-properties 0)
					    (match-end 0) t)))
	 ((looking-at (rst-re 'lin-end))
	  ;; Empty line found - check surrounding lines for a title.
	  (or
	   (rst-forward-line-looking-at -1 'ttl-beg-1 cnd-fun)
	   (rst-forward-line-looking-at +1 'ttl-beg-1 cnd-fun)))
	 ((looking-at (rst-re 'ttl-beg-1))
	  ;; Title line found - check for a following underline.
	  (setq ttl (rst-forward-line-looking-at
		     1 'ado-beg-2-1
                     (lambda (mtcd)
                       (when mtcd
                         (rst-classify-adornment
                          (match-string-no-properties 0) (match-end 0))))))
	  ;; Title candidate found if no valid adornment found.
	  (funcall cnd-fun (not ttl))))
	(cond
	 ((and ttl (rst-Ttl-is-section ttl))
	  ttl)
	 (cnd-beg
	  (rst-Ttl-from-buffer nil nil cnd-beg nil cnd-txt)))))))

;; The following function and variables are used to maintain information about
;; current section adornment in a buffer local cache. Thus they can be used for
;; font-locking and manipulation commands.

(defvar-local rst-all-ttls-cache nil
  "All section adornments in the buffer as found by `rst-all-ttls'.
Set to t when no section adornments were found.")

;; FIXME: If this variable is set to a different value font-locking of section
;;        headers is wrong.
(defvar-local rst-hdr-hierarchy-cache nil
  "Section hierarchy in the buffer as determined by `rst-hdr-hierarchy'.
Set to t when no section adornments were found.
Value depends on `rst-all-ttls-cache'.")

(rst-testcover-add-1value 'rst-reset-section-caches)
(defun rst-reset-section-caches ()
  "Reset all section cache variables.
Should be called by interactive functions which deal with sections."
  (setq rst-all-ttls-cache nil
	rst-hdr-hierarchy-cache nil))

(defun rst-all-ttls-compute ()
  ;; testcover: ok.
  "Return a list of `rst-Ttl' for current buffer with ascending line number."
  (save-excursion
    (save-match-data
      (let (ttls)
	(goto-char (point-min))
	;; Iterate over all the section titles/adornments in the file.
	(while (re-search-forward (rst-re 'ado-beg-2-1) nil t)
	  (let ((ttl (rst-classify-adornment
		      (match-string-no-properties 0) (point))))
	    (when (and ttl (rst-Ttl-is-section ttl))
	      (when (rst-Ttl-hdr ttl)
		(push ttl ttls))
	      (goto-char (rst-Ttl-get-end ttl)))))
	(nreverse ttls)))))

(defun rst-all-ttls ()
  "Return all the section adornments in the current buffer.
Return a list of `rst-Ttl' with ascending line number.

Uses and sets `rst-all-ttls-cache'."
  (unless rst-all-ttls-cache
    (setq rst-all-ttls-cache (or (rst-all-ttls-compute) t)))
  (if (eq rst-all-ttls-cache t)
      nil
    (copy-sequence rst-all-ttls-cache)))

(defun rst-infer-hdr-hierarchy (hdrs)
  ;; testcover: ok.
  "Build a hierarchy from HDRS.
HDRS reflects the order in which the headers appear in the
buffer.  Return a `rst-Hdr' list representing the hierarchy of
headers in the buffer.  Indentation is unified."
  (let (ado2indents) ; Associates `rst-Ado' with the set of indents seen for it.
    (dolist (hdr hdrs)
      (let* ((ado (rst-Hdr-ado hdr))
	     (indent (rst-Hdr-indent hdr))
	     (found (assoc ado ado2indents)))
        (if found
	    (setcdr found (cl-adjoin indent (cdr found)))
	  (push (list ado indent) ado2indents))))
    (mapcar (cl-function
	     (lambda ((ado consistent &rest inconsistent))
	       (rst-Hdr-new ado (if inconsistent
				    rst-default-indent
				  consistent))))
	    (nreverse ado2indents))))

(defun rst-hdr-hierarchy (&optional ignore-position)
  ;; testcover: ok.
  "Return the hierarchy of section titles in the file as a `rst-Hdr' list.
Each returned element may be used directly to create a section
adornment on that level.  If IGNORE-POSITION a title containing
this position is not taken into account when building the
hierarchy unless it appears again elsewhere.  This catches cases
where the current title is edited and may not be final regarding
its level.

Uses and sets `rst-hdr-hierarchy-cache' unless IGNORE-POSITION is
given."
  (let* ((all-ttls (rst-all-ttls))
	 (ignore-ttl
	  (if ignore-position
	      (cl-find-if
               (lambda (ttl)
                 (equal (rst-Ttl-contains ttl ignore-position) 0))
	       all-ttls)))
	 (really-ignore
	  (if ignore-ttl
	      (<= (cl-count-if
                   (lambda (ttl)
                     (rst-Ado-equal (rst-Ttl-ado ignore-ttl)
                                 (rst-Ttl-ado ttl)))
		   all-ttls)
		  1)))
	 (real-ttls (delq (if really-ignore ignore-ttl) all-ttls)))
    (copy-sequence ; Protect cache.
     (if (and (not ignore-position) rst-hdr-hierarchy-cache)
	 (if (eq rst-hdr-hierarchy-cache t)
	     nil
	   rst-hdr-hierarchy-cache)
       (let ((r (rst-infer-hdr-hierarchy (mapcar #'rst-Ttl-hdr real-ttls))))
	 (setq rst-hdr-hierarchy-cache
	       (if ignore-position
		   ;; Clear cache reflecting that a possible update is not
		   ;; reflected.
		   nil
		 (or r t)))
	 r)))))

(defun rst-all-ttls-with-level ()
  ;; testcover: ok.
  "Return the section adornments with levels set according to hierarchy.
Return a list of (`rst-Ttl' . LEVEL) with ascending line number."
  (let ((hier (rst-Hdr-ado-map (rst-hdr-hierarchy))))
    (mapcar
     (lambda (ttl)
       (cons ttl (rst-Ado-position (rst-Ttl-ado ttl) hier)))
     (rst-all-ttls))))

(defun rst-get-previous-hdr ()
  "Return the `rst-Hdr' before point or nil if none."
  (let ((prev (cl-find-if (lambda (ttl)
                            (< (rst-Ttl-contains ttl (point)) 0))
			  (rst-all-ttls)
			  :from-end t)))
    (and prev (rst-Ttl-hdr prev))))

(defun rst-adornment-complete-p (ado indent)
  ;; testcover: ok.
  "Return t if the adornment ADO around point is complete using INDENT.
The adornment is complete if it is a completely correct
reStructuredText adornment for the title line at point.  This
includes indentation and correct length of adornment lines."
  ;; Note: we assume that the detection of the overline as being the underline
  ;; of a preceding title has already been detected, and has been eliminated
  ;; from the adornment that is given to us.
  (let ((exps (list "^" (rst-Ado-char ado)
		    (format "\\{%d\\}"
			    (+ (save-excursion
				 ;; Determine last column of title.
				 (end-of-line)
				 (current-column))
			       indent)) "$")))
    (and (rst-forward-line-looking-at +1 exps)
	 (or (rst-Ado-is-simple ado)
	     (rst-forward-line-looking-at -1 exps))
	 t))) ; Normalize return value.

(defun rst-next-hdr (hdr hier prev down)
  ;; testcover: ok.
  "Return the next best `rst-Hdr' upward from HDR.
Consider existing hierarchy HIER and preferred headers.  PREV may
be a previous `rst-Hdr' which may be taken into account.  If DOWN
return the next best `rst-Hdr' downward instead.  Return nil if
HIER is nil."
  (let* ((normalized-hier (if down
			      hier
			    (reverse hier)))
	 (fnd (rst-Hdr-member-ado hdr normalized-hier))
	 (prev-fnd (and prev (rst-Hdr-member-ado prev normalized-hier))))
    (or
     ;; Next entry in existing hierarchy if it exists.
     (cadr fnd)
     (if fnd
	 ;; If current header is found try introducing a new one from preferred
	 ;; hierarchy.
	 (rst-new-preferred-hdr hier prev)
       ;; If not found try using previous header.
       (if down
	   (cadr prev-fnd)
	 (car prev-fnd)))
     ;; All failed - rotate by using first from normalized existing hierarchy.
     (car normalized-hier))))

;; FIXME: A line "``/`` full" is not accepted as a section title.
(defun rst-adjust (pfxarg)
  ;; testcover: ok.
  "Auto-adjust the adornment around point.
Adjust/rotate the section adornment for the section title around
point or promote/demote the adornments inside the region,
depending on whether the region is active.  This function is meant
to be invoked possibly multiple times, and can vary its behavior
with a positive PFXARG (toggle style), or with a negative
PFXARG (alternate behavior).

This function is a bit of a swiss knife.  It is meant to adjust
the adornments of a section title in reStructuredText.  It tries
to deal with all the possible cases gracefully and to do \"the
right thing\" in all cases.

See the documentations of `rst-adjust-section' and
`rst-adjust-region' for full details.

The method can take either (but not both) of

a. a (non-negative) prefix argument, which means to toggle the
   adornment style.  Invoke with a prefix argument for example;

b. a negative numerical argument, which generally inverts the
   direction of search in the file or hierarchy.  Invoke with C--
   prefix for example."
  (interactive "P")
  (let* ((origpt (point-marker))
         (reverse-direction (and pfxarg (< (prefix-numeric-value pfxarg) 0)))
         (toggle-style (and pfxarg (not reverse-direction))))
    (if (use-region-p)
        (rst-adjust-region (and pfxarg t))
      (let ((msg (rst-adjust-section toggle-style reverse-direction)))
	(when msg
	  (apply #'message msg))))
    (run-hooks 'rst-adjust-hook)
    (rst-reset-section-caches)
    (set-marker
     (goto-char origpt) nil)))

(defcustom rst-adjust-hook nil
  "Hooks to be run after running `rst-adjust'."
  :group 'rst-adjust
  :type '(hook)
  :package-version '(rst . "1.1.0"))

(defcustom rst-new-adornment-down nil
  "Controls level of new adornment for section headers."
  :group 'rst-adjust
  :type '(choice
	  (const :tag "Same level as previous one" nil)
	  (const :tag "One level down relative to the previous one" t))
  :package-version '(rst . "1.1.0"))

(defun rst-adjust-adornment (pfxarg)
  "Call `rst-adjust-section' interactively.
Keep this for compatibility for older bindings (are there any?).
Argument PFXARG has the same meaning as for `rst-adjust'."
  (interactive "P")

  (let* ((reverse-direction (and pfxarg (< (prefix-numeric-value pfxarg) 0)))
         (toggle-style (and pfxarg (not reverse-direction))))
    (rst-adjust-section toggle-style reverse-direction)))

(defun rst-adjust-new-hdr (toggle-style reverse ttl)
  ;; testcover: ok.
  "Return a new `rst-Hdr' for `rst-adjust-section' related to TTL.
TOGGLE-STYLE and REVERSE are from
`rst-adjust-section'.  TOGGLE-STYLE may be consumed and thus is
returned.

Return a list (HDR TOGGLE-STYLE MSG...).  HDR is the result or
nil.  TOGGLE-STYLE is the new TOGGLE-STYLE to use in the
caller.  MSG is a list which is non-empty in case HDR is nil
giving an argument list for `message'."
  (save-excursion
    (goto-char (rst-Ttl-get-title-beginning ttl))
    (let ((indent (rst-Ttl-indent ttl))
	  (ado (rst-Ttl-ado ttl))
	  (prev (rst-get-previous-hdr))
	  hdr-msg)
      (setq
       hdr-msg
       (cond
	((rst-Ttl-is-candidate ttl)
	 ;; Case 1: No adornment at all.
	 (let ((hier (rst-hdr-hierarchy)))
	   (if prev
	       ;; Previous header exists - use it.
	       (cond
		;; Customization and parameters require that the previous level
		;; is used - use it as is.
		((or (and rst-new-adornment-down reverse)
		     (and (not rst-new-adornment-down) (not reverse)))
		 prev)
		;; Advance one level down.
		((rst-next-hdr prev hier prev t))
		("Neither hierarchy nor preferences can suggest a deeper header"))
	     ;; First header in the buffer - use the first adornment from
	     ;; preferences or hierarchy.
	     (let ((p (car (rst-Hdr-preferred-adornments)))
		   (h (car hier)))
	       (cond
		((if reverse
		     ;; Prefer hierarchy for downwards
		     (or h p)
		   ;; Prefer preferences for upwards
		   (or p h)))
		("No preferences to suggest a top level from"))))))
	((not (rst-adornment-complete-p ado indent))
	 ;; Case 2: Incomplete adornment.
	 ;; Use lax since indentation might not match suggestion.
	 (rst-Hdr-new-lax ado indent))
	;; Case 3: Complete adornment exists from here on.
	(toggle-style
	 ;; Simply switch the style of the current adornment.
	 (setq toggle-style nil) ; Remember toggling has been done.
	 (rst-Hdr-new-invert ado rst-default-indent))
	(t
	 ;; Rotate, ignoring a sole adornment around the current line.
	 (let ((hier (rst-hdr-hierarchy (point))))
	   (cond
	    ;; Next header can be determined from hierarchy or preferences.
	    ((rst-next-hdr
	      ;; Use lax since indentation might not match suggestion.
	      (rst-Hdr-new-lax ado indent) hier prev reverse))
	    ;; No next header found.
	    ("No preferences or hierarchy to suggest another level from"))))))
      (if (stringp hdr-msg)
	  (list nil toggle-style hdr-msg)
	(list hdr-msg toggle-style)))))

(defun rst-adjust-section (toggle-style reverse)
  ;; testcover: ok.
  "Adjust/rotate the section adornment for the section title around point.
The action this function takes depends on context around the
point, and it is meant to be invoked possibly more than once to
rotate among the various possibilities.  Basically, this function
deals with:

- adding an adornment if the title does not have one;

- adjusting the length of the underline characters to fit a
  modified title;

- rotating the adornment in the set of already existing
  sectioning adornments used in the file;

- switching between simple and over-and-under styles by giving
  TOGGLE-STYLE.

Return nil if the function did something.  If the function were
not able to do something return an argument list for `message' to
inform the user about what failed.

The following is a detailed description but you should normally
not have to read it.

Before applying the adornment change, the cursor is placed on the
closest line that could contain a section title if such is found
around the cursor.  Then the following cases are distinguished.

* Case 1: No Adornment

  If the current line has no adornment around it,

  - search for a previous adornment, and apply this adornment (unless
    `rst-new-adornment-down') or one level lower (otherwise) to the current
    line.  If there is no defined level below this previous adornment, we
    suggest the most appropriate of the `rst-preferred-adornments'.

    If REVERSE is true, we simply use the previous adornment found
    directly.

  - if there is no adornment found in the given direction, we use the first of
    `rst-preferred-adornments'.

  TOGGLE-STYLE forces a toggle of the prescribed adornment style.

* Case 2: Incomplete Adornment

  If the current line does have an existing adornment, but the adornment is
  incomplete, that is, the underline/overline does not extend to exactly the
  end of the title line (it is either too short or too long), we simply extend
  the length of the underlines/overlines to fit exactly the section title.

  If TOGGLE-STYLE we toggle the style of the adornment as well.

  REVERSE has no effect in this case.

* Case 3: Complete Existing Adornment

  If the adornment is complete (i.e. the underline (overline) length is already
  adjusted to the end of the title line), we rotate the current title's
  adornment according to the adornment hierarchy found in the buffer.  This is
  meant to be used potentially multiple times, until the desired adornment is
  found around the title.

  If we hit the boundary of the hierarchy, exactly one choice from the list of
  preferred adornments is suggested/chosen, the first of those adornment that
  has not been seen in the buffer yet, and the next invocation rolls over to
  the other end of the hierarchy (i.e. it cycles).

  If REVERSE is we go up in the hierarchy.  Otherwise we go down.

  However, if TOGGLE-STYLE, we do not rotate the adornment, but instead simply
  toggle the style of the current adornment."
  (rst-reset-section-caches)
  (let ((ttl (rst-ttl-at-point)))
    (if (not ttl)
	'("No section header or candidate at point")
      (cl-destructuring-bind
	  (hdr toggle-style &rest msg
	       &aux
	       (indent (rst-Ttl-indent ttl))
	       (moved (- (line-number-at-pos (rst-Ttl-get-title-beginning ttl))
			 (line-number-at-pos))))
	  (rst-adjust-new-hdr toggle-style reverse ttl)
	(if msg
	    msg
	  (when toggle-style
	    (setq hdr (rst-Hdr-new-invert (rst-Hdr-ado hdr) indent)))
	  ;; Override indent with present indent if there is some.
	  (when (> indent 0)
	    ;; Use lax since existing indent may not be valid for new style.
	    (setq hdr (rst-Hdr-new-lax (rst-Hdr-ado hdr) indent)))
	  (goto-char (rst-Ttl-get-title-beginning ttl))
	  (rst-update-section hdr)
	  ;; Correct the position of the cursor to more accurately reflect
	  ;; where it was located when the function was invoked.
	  (unless (zerop moved)
	    (1value ; No lines may be left to move.
	     (rst-forward-line-strict (- moved)))
	    (end-of-line))
	  nil)))))

;; Maintain an alias for compatibility.
(defalias 'rst-adjust-section-title 'rst-adjust)

(defun rst-adjust-region (demote)
  ;; testcover: ok.
  "Promote the section titles within the region.
With argument DEMOTE or a prefix argument, demote the section
titles instead.  The algorithm used at the boundaries of the
hierarchy is similar to that used by `rst-adjust-section'."
  (interactive "P")
  (rst-reset-section-caches)
  (let* ((beg (region-beginning))
	 (end (region-end))
	 (ttls-reg (cl-remove-if-not
                    (lambda (ttl)
                      (and
                       (>= (rst-Ttl-contains ttl beg) 0)
                       (< (rst-Ttl-contains ttl end) 0)))
		    (rst-all-ttls))))
    (save-excursion
      ;; Apply modifications.
      (rst-destructuring-dolist
	  ((marker &rest hdr
		   &aux (hier (rst-hdr-hierarchy)))
           (mapcar (lambda (ttl)
                     (cons (copy-marker (rst-Ttl-get-title-beginning ttl))
                           (rst-Ttl-hdr ttl)))
		   ttls-reg))
	(set-marker
	 (goto-char marker) nil)
	;; `rst-next-hdr' cannot return nil because we apply to a section
	;; header so there is some hierarchy.
	(rst-update-section (rst-next-hdr hdr hier nil demote)))
      (setq deactivate-mark nil))))

(defun rst-display-hdr-hierarchy ()
  ;; testcover: ok.
  "Display the current file's section title adornments hierarchy.
Hierarchy is displayed in a temporary buffer."
  (interactive)
  (rst-reset-section-caches)
  (let ((hdrs (rst-hdr-hierarchy))
	(level 1))
    (with-output-to-temp-buffer "*rest section hierarchy*"
      (with-current-buffer standard-output
	(dolist (hdr hdrs)
	  (insert (format "\nSection Level %d" level))
	  (rst-update-section hdr)
	  (goto-char (point-max))
	  (insert "\n")
	  (cl-incf level))))))

;; Maintain an alias for backward compatibility.
(defalias 'rst-display-adornments-hierarchy 'rst-display-hdr-hierarchy)

;; FIXME: Should accept an argument giving the hierarchy level to start with
;;        instead of the top of the hierarchy.
(defun rst-straighten-sections ()
  ;; testcover: ok.
  "Redo the adornments of all section titles in the current buffer.
This is done using the preferred set of adornments.  This can be
used, for example, when using somebody else's copy of a document,
in order to adapt it to our preferred style."
  (interactive)
  (rst-reset-section-caches)
  (save-excursion
    (rst-destructuring-dolist
	((marker &rest level)
	 (mapcar
	  (cl-function
	   (lambda ((ttl &rest level))
	     ;; Use markers so edits don't disturb the position.
	     (cons (copy-marker (rst-Ttl-get-title-beginning ttl)) level)))
	  (rst-all-ttls-with-level)))
      (set-marker
       (goto-char marker) nil)
      (rst-update-section (nth level (rst-Hdr-preferred-adornments))))))

;; Maintain an alias for compatibility.
(defalias 'rst-straighten-adornments 'rst-straighten-sections)


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Insert list items

;; Borrowed from a2r.el (version 1.3), by Lawrence Mitchell <wence@gmx.li>.  I
;; needed to make some tiny changes to the functions, so I put it here.
;; -- Wei-Wei Guo

(defconst rst-arabic-to-roman
  '((1000 .   "M") (900  .  "CM") (500  .   "D") (400  .  "CD")
    (100  .   "C") (90   .  "XC") (50   .   "L") (40   .  "XL")
    (10   .   "X") (9    .  "IX") (5    .   "V") (4    .  "IV")
    (1    .   "I"))
  "List of maps between Arabic numbers and their Roman numeral equivalents.")

(defun rst-arabic-to-roman (num)
  ;; testcover: ok.
  "Convert Arabic number NUM to its Roman numeral representation.

Obviously, NUM must be greater than zero.  Don't blame me, blame the
Romans, I mean \"what have the Romans ever _done_ for /us/?\" (with
apologies to Monty Python)."
  (cl-check-type num (integer 1 *))
  (let ((map rst-arabic-to-roman)
        (r ""))
    (while (and map (> num 0))
      (cl-destructuring-bind ((val &rest sym) &rest next) map
	(if (>= num val)
	    (setq r (concat r sym)
		  num (- num val))
	  (setq map next))))
    r))

(defun rst-roman-to-arabic (string)
  ;; testcover: ok.
  "Convert STRING of Roman numerals to an Arabic number.
If STRING contains a letter which isn't a valid Roman numeral,
the rest of the string from that point onwards is ignored.
Hence:
MMD == 2500
and
MMDFLXXVI == 2500."
  (cl-check-type string string)
  (cl-check-type string (satisfies (lambda (s)
				     (not (equal s ""))))
		 "Roman number may not be an empty string.")
  (let ((res 0)
        (map rst-arabic-to-roman))
    (save-match-data
      (while map
	(cl-destructuring-bind ((val &rest sym) &rest next) map
	  (if (string-match (concat "^" sym) string)
	      (setq res (+ res val)
		    string (replace-match "" nil t string))
	    (setq map next))))
      (cl-check-type string (satisfies (lambda (s)
					 (equal s "")))
		     "Invalid characters in roman number")
      res)))

;; End of borrow.

;; FIXME: All the following code should not consider single lines as items but
;;        paragraphs as reST does.

(defun rst-insert-list-new-tag (tag)
  ;; testcover: ok.
  "Insert first item of a new list tagged with TAG.

Adding a new list might consider three situations:

 (a) Current line is a blank line.
 (b) Previous line is a blank line.
 (c) Following line is a blank line.

When (a) and (b), just add the new list at current line.

when (a) and not (b), a blank line is added before adding the new list.

When not (a), first forward point to the end of the line, and add two
blank lines, then add the new list.

Other situations are just ignored and left to users themselves."
  ;; FIXME: Following line is not considered at all.
  (let ((pfx-nls
	 ;; FIXME: Doesn't work properly for white-space line. See
	 ;;        `rst-insert-list-new-BUGS'.
	 (if (rst-forward-line-looking-at 0 'lin-end)
	     (if (not (rst-forward-line-looking-at -1 'lin-end #'not))
		 0
	       1)
	   2)))
    (end-of-line)
    ;; FIXME: The indentation is not fixed to a single space by the syntax. May
    ;;        be this should be configurable or rather taken from the context.
    (insert (make-string pfx-nls ?\n) tag " ")))

(defconst rst-initial-items
  (append (mapcar #'char-to-string rst-bullets)
	  (let (vals)
	    (dolist (fmt '("%s." "(%s)" "%s)"))
	      (dolist (c '("#" "1" "a" "A" "I" "i"))
		(push (format fmt c) vals)))
	    (nreverse vals)))
  "List of initial items.  It's a collection of bullets and enumerations.")

(defun rst-insert-list-new-item ()
  ;; testcover: ok.
  "Insert a new list item.

User is asked to select the item style first, for example (a), i), +.
Use TAB for completion and choices.

If user selects bullets or #, it's just added with position arranged by
`rst-insert-list-new-tag'.

If user selects enumerations, a further prompt is given.  User need to
input a starting item, for example 'e' for 'A)' style.  The position is
also arranged by `rst-insert-list-new-tag'."
  (let* ((itemstyle (completing-read
		     (format-prompt "Select preferred item style" "#.")
		     rst-initial-items nil t nil nil "#."))
	 (cnt (if (string-match (rst-re 'cntexp-tag) itemstyle)
		  (match-string 0 itemstyle)))
	 (no
	  (save-match-data
	    (cond
	     ((equal cnt "a")
	      (let ((itemno (read-string
                             (format-prompt "Give starting value" "a")
			     nil nil "a")))
		(downcase (substring itemno 0 1))))
	     ((equal cnt "A")
	      (let ((itemno (read-string
                             (format-prompt "Give starting value" "A")
			     nil nil "A")))
		(upcase (substring itemno 0 1))))
	     ((equal cnt "I")
	      (let ((itemno (read-number "Give starting value: " 1)))
		(rst-arabic-to-roman itemno)))
	     ((equal cnt "i")
	      (let ((itemno (read-number "Give starting value: " 1)))
		(downcase (rst-arabic-to-roman itemno))))
	     ((equal cnt "1")
	      (let ((itemno (read-number "Give starting value: " 1)))
		(number-to-string itemno)))))))
    (if no
	(setq itemstyle (replace-match no t t itemstyle)))
    (rst-insert-list-new-tag itemstyle)))

(defcustom rst-preferred-bullets
  '(?* ?- ?+)
  "List of favorite bullets."
  :group 'rst
  :type `(repeat
          (choice ,@(mapcar (lambda (char)
                              (list 'const
                                    :tag (char-to-string char) char))
			    rst-bullets)))
  :package-version '(rst . "1.1.0"))

(defun rst-insert-list-continue (ind tag tab prefer-roman)
  ;; testcover: ok.
  "Insert a new list tag after the current line according to style.
Style is defined by indentation IND, TAG and suffix TAB.  If
PREFER-ROMAN roman numbering is preferred over using letters."
  (end-of-line)
  (insert
   ;; FIXME: Separating lines must be possible.
   "\n"
   ind
   (save-match-data
     (if (not (string-match (rst-re 'cntexp-tag) tag))
	 tag
       (let ((pfx (substring tag 0 (match-beginning 0)))
	     (cnt (match-string 0 tag))
	     (sfx (substring tag (match-end 0))))
	 (concat
	  pfx
	  (cond
	   ((string-match (rst-re 'num-tag) cnt)
	    (number-to-string (1+ (string-to-number (match-string 0 cnt)))))
	   ((and
	     (string-match (rst-re 'rom-tag) cnt)
	     (save-match-data
	       (if (string-match (rst-re 'ltr-tag) cnt) ; Also a letter tag.
		   (save-excursion
		     ;; FIXME: Assumes one line list items without separating
		     ;;        empty lines.
		     ;; Use of `rst-forward-line-looking-at' is very difficult
		     ;; here so don't do it.
		     (if (and (rst-forward-line-strict -1)
			      (looking-at (rst-re 'enmexp-beg)))
			 (string-match
			  (rst-re 'rom-tag)
			  (match-string 0)) ; Previous was a roman tag.
		       prefer-roman)) ; Don't know - use flag.
		 t))) ; Not a letter tag.
	    (let* ((old (match-string 0 cnt))
		   (new (rst-arabic-to-roman
			 (1+ (rst-roman-to-arabic (upcase old))))))
	      (if (equal old (upcase old))
		  (upcase new)
		(downcase new))))
	   ((string-match (rst-re 'ltr-tag) cnt)
	    (char-to-string (1+ (string-to-char (match-string 0 cnt))))))
	  sfx))))
    tab))

;; FIXME: At least the continuation may be folded into
;;        'newline-and-indent'. However, this may not be wanted by everyone so
;;        it should be possible to switch this off.
(defun rst-insert-list (&optional prefer-roman)
  ;; testcover: ok.
  "Insert a list item at the current point.

The command can insert a new list or a continuing list.  When it is called at a
non-list line, it will promote to insert new list.  When it is called at a list
line, it will insert a list with the same list style.

1. When inserting a new list:

User is asked to select the item style first, for example (a), i), +.  Use TAB
for completion and choices.

 (a) If user selects bullets or #, it's just added.
 (b) If user selects enumerations, a further prompt is given.  User needs to
     input a starting item, for example `e' for `A)' style.

The position of the new list is arranged according to whether or not the
current line and the previous line are blank lines.

2. When continuing a list, one thing needs to be noticed:

List style alphabetical list, such as `a.', and roman numerical list, such as
`i.', have some overlapping items, for example `v.' The function can deal with
the problem elegantly in most situations.  But when those overlapped list are
preceded by a blank line, it is hard to determine which type to use
automatically.  The function uses alphabetical list by default.  If you want
roman numerical list, just use a prefix to set PREFER-ROMAN."
  (interactive "P")
  (save-match-data
    (1value
     (rst-forward-line-strict 0))
    ;; FIXME: Finds only tags in single line items. Multi-line items should be
    ;;        considered as well.
    ;; Using `rst-forward-line-looking-at' is more complicated so don't do it.
    (if (looking-at (rst-re 'itmany-beg-1))
	(rst-insert-list-continue
	 (buffer-substring-no-properties
	  (match-beginning 0) (match-beginning 1))
	 (match-string 1)
	 (buffer-substring-no-properties (match-end 1) (match-end 0))
	 prefer-roman)
      (rst-insert-list-new-item))))

;; FIXME: This is wrong because it misses prefixed lines without intervening
;;        new line. See `rst-straighten-bullets-region-BUGS' and
;;        `rst-find-begs-BUGS'.
(defun rst-find-begs (beg end rst-re-beg)
  ;; testcover: ok.
  "Return the positions of begs in region BEG to END.
RST-RE-BEG is a `rst-re' argument and matched at the beginning of
a line.  Return a list of (POINT . COLUMN) where POINT gives the
point after indentation and COLUMN gives its column.  The list is
ordered by POINT."
  (let (r)
    (save-match-data
      (save-excursion
	;; FIXME refactoring: Consider making this construct a macro looping
	;;                    over the lines.
	(goto-char beg)
	(1value
	 (rst-forward-line-strict 0))
	(while (< (point) end)
	  (let ((clm (current-indentation)))
	    ;; FIXME refactoring: Consider using `rst-forward-line-looking-at'.
	    (when (and
		   (looking-at (rst-re rst-re-beg)) ; Start found
		   (not (rst-forward-line-looking-at
			 -1 'lin-end
                         (lambda (mtcd) ; Previous line exists and is...
                           (and
                            (not mtcd) ; non-empty,
                            (<= (current-indentation) clm) ; less indented
                            (not (and (= (current-indentation) clm)
					; not a beg at same level.
                                      (looking-at (rst-re rst-re-beg)))))))))
	      (back-to-indentation)
	      (push (cons (point) clm) r)))
	  (1value ; At least one line is moved in this loop.
	   (rst-forward-line-strict 1 end)))))
    (nreverse r)))

(defun rst-straighten-bullets-region (beg end)
  ;; testcover: ok.
  "Make all the bulleted list items in the region from BEG to END consistent.
Use this after you have merged multiple bulleted lists to make
them use the preferred bullet characters given by
`rst-preferred-bullets' for each level.  If bullets are found on
levels beyond the `rst-preferred-bullets' list, they are not
modified."
  (interactive "r")
  (save-excursion
    (let (clm2pnts) ; Map a column to a list of points at this column.
      (rst-destructuring-dolist
	  ((point &rest column
		  &aux (found (assoc column clm2pnts)))
	   (rst-find-begs beg end 'bul-beg))
	(if found
	    ;;; (push point (cdr found)) ; FIXME: Doesn't work with `testcover'.
	    (setcdr found (cons point (cdr found))) ; Synonym.
	  (push (list column point) clm2pnts)))
      (rst-destructuring-dolist
	  ((bullet _clm &rest pnts)
	   ;; Zip preferred bullets and sorted columns associating a bullet
	   ;; with a column and all the points this column is found.
           (cl-mapcar (lambda (bullet clm2pnt)
                        (cons bullet clm2pnt))
		      rst-preferred-bullets
		      (sort clm2pnts #'car-less-than-car)))
	;; Replace the bullets by the preferred ones.
	(dolist (pnt pnts)
	  (goto-char pnt)
	  ;; FIXME: Assumes bullet to replace is a single char.
	  (delete-char 1)
	  (insert bullet))))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Table of contents

(defun rst-all-stn ()
  ;; testcover: ok.
  "Return the hierarchical tree of sections as a top level `rst-Stn'.
Return value satisfies `rst-Stn-is-top' or is nil for no
sections."
  (cdr (rst-remaining-stn (rst-all-ttls-with-level) -1)))

(defun rst-remaining-stn (unprocessed expected)
  ;; testcover: ok.
  "Process the first entry of UNPROCESSED expected to be on level EXPECTED.
UNPROCESSED is the remaining list of (`rst-Ttl' . LEVEL) entries.
Return (REMAINING . STN) for the first entry of UNPROCESSED.
REMAINING is the list of still unprocessed entries.  STN is a
`rst-Stn' or nil if UNPROCESSED is empty."
  (if (not unprocessed)
      (1value
       (cons nil nil))
    (cl-destructuring-bind
	((ttl &rest level) &rest next
	 &aux fnd children)
	unprocessed
      (when (= level expected)
	;; Consume the current entry and create the current node with it.
	(setq fnd ttl)
	(setq unprocessed next))
      ;; Build the child nodes as long as they have deeper level.
      (while (and unprocessed (> (cdar unprocessed) expected))
	(cl-destructuring-bind (remaining &rest stn)
	    (rst-remaining-stn unprocessed (1+ expected))
	  (when stn
	    (push stn children))
	  (setq unprocessed remaining)))
      (cons unprocessed
	    (when (or fnd children)
	      (rst-Stn-new fnd expected (nreverse children)))))))

(defun rst-stn-containing-point (stn &optional point)
  ;; testcover: ok.
  "Return `rst-Stn' in STN before POINT or nil if in no section.
POINT defaults to the current point.  STN may be nil for no
section headers at all."
  (when stn
    (setq point (or point (point)))
    (when (>= point (rst-Stn-get-title-beginning stn))
      ;; Point may be in this section or a child.
      (let ((in-child (cl-find-if
                       (lambda (child)
                         (>= point (rst-Stn-get-title-beginning child)))
		       (rst-Stn-children stn)
		       :from-end t)))
	(if in-child
	    (rst-stn-containing-point in-child point)
	  stn)))))

(defgroup rst-toc nil
  "Settings for reStructuredText table of contents."
  :group 'rst
  :version "21.1")

(defcustom rst-toc-indent 2
  "Indentation for table-of-contents display.
Also used for formatting insertion, when numbering is disabled."
  :type 'integer
  :group 'rst-toc)

(defcustom rst-toc-insert-style 'fixed
  "Insertion style for table-of-contents.
Set this to one of the following values to determine numbering and
indentation style:
- `plain': no numbering (fixed indentation)
- `fixed': numbering, but fixed indentation
- `aligned': numbering, titles aligned under each other
- `listed': titles as list items"
  :type '(choice (const plain)
                 (const fixed)
                 (const aligned)
                 (const listed))
  :group 'rst-toc)

(defcustom rst-toc-insert-number-separator "  "
  "Separator that goes between the TOC number and the title."
  :type 'string
  :group 'rst-toc)

(defcustom rst-toc-insert-max-level nil
  "If non-nil, maximum depth of the inserted TOC."
  :type '(choice (const nil) integer)
  :group 'rst-toc)

(defconst rst-toc-link-keymap
  (let ((map (make-sparse-keymap)))
       (define-key map [mouse-1] 'rst-toc-mouse-follow-link)
       map)
  "Keymap used for links in TOC.")

(defun rst-toc-insert (&optional max-level)
  ;; testcover: ok.
  "Insert the table of contents of the current section at the current column.
By default the top level is ignored if there is only one, because
we assume that the document will have a single title.  A numeric
prefix argument MAX-LEVEL overrides `rst-toc-insert-max-level'.
Text in the line beyond column is deleted."
  (interactive "P")
  (rst-reset-section-caches)
  (let ((pt-stn (rst-stn-containing-point (rst-all-stn))))
    (when pt-stn
      (let ((max
	     (if (and (integerp max-level)
		      (> (prefix-numeric-value max-level) 0))
		 (prefix-numeric-value max-level)
	       rst-toc-insert-max-level))
	    (ind (current-column))
	    (buf (current-buffer))
	    (tabs indent-tabs-mode) ; Copy buffer local value.
	    txt)
	(setq txt
	      ;; Render to temporary buffer so markers are created correctly.
	      (with-temp-buffer
		(rst-toc-insert-tree pt-stn buf rst-toc-insert-style max
				     rst-toc-link-keymap nil)
		(goto-char (point-min))
		(when (rst-forward-line-strict 1)
		  ;; There are lines to indent.
		  (let ((indent-tabs-mode tabs))
		    (indent-rigidly (point) (point-max) ind)))
		(buffer-string)))
	(unless (zerop (length txt))
	  ;; Delete possible trailing text.
	  (delete-region (point) (line-beginning-position 2))
	  (insert txt)
	  (backward-char 1))))))

(defun rst-toc-insert-link (pfx stn buf keymap)
  ;; testcover: ok.
  "Insert text of STN in BUF as a linked section reference at point.
If KEYMAP use this as keymap property.  PFX is inserted before text."
  (let ((beg (point)))
    (insert pfx)
    (insert (rst-Stn-get-text stn))
    (put-text-property beg (point) 'mouse-face 'highlight)
    (insert "\n")
    (put-text-property
     beg (point) 'rst-toc-target
     (set-marker (make-marker) (rst-Stn-get-title-beginning stn) buf))
    (when keymap
      (put-text-property beg (point) 'keymap keymap))))

(defun rst-toc-get-link (link-buf link-pnt)
  ;; testcover: ok.
  "Return the link from text property at LINK-PNT in LINK-BUF."
  (let ((mrkr (get-text-property link-pnt 'rst-toc-target link-buf)))
    (unless mrkr
      (error "No section on this line"))
    (unless (buffer-live-p (marker-buffer mrkr))
      (error "Buffer for this section was killed"))
    mrkr))

(defun rst-toc-insert-tree (stn buf style depth keymap tgt-stn)
  ;; testcover: ok.
  "Insert table of contents of tree below top node STN in buffer BUF.
STYLE is the style to use and must be one of the symbols allowed
for `rst-toc-insert-style'.  DEPTH is the maximum relative depth
from STN to insert or nil for no maximum depth.  See
`rst-toc-insert-link' for KEYMAP.  Return beginning of title line
if TGT-STN is rendered or nil if not rendered or TGT-STN is nil.
Just return nil if STN is nil."
  (when stn
    (rst-toc-insert-children (rst-Stn-children stn) buf style depth 0 "" keymap
			     tgt-stn)))

(defun rst-toc-insert-children (children buf style depth indent numbering
					 keymap tgt-stn)
  ;; testcover: ok.
  "In the current buffer at point insert CHILDREN in BUF to table of contents.
See `rst-toc-insert-tree' for STYLE, DEPTH and TGT-STN.  See
`rst-toc-insert-stn' for INDENT and NUMBERING.  See
`rst-toc-insert-link' for KEYMAP."
  (let ((count 1)
	;; Child numbering is done from the parent.
	(num-fmt (format "%%%dd"
			 (1+ (floor (log (1+ (length children)) 10)))))
	fnd)
    (when (not (equal numbering ""))
      ;; Add separating dot to existing numbering.
      (setq numbering (concat numbering ".")))
    (dolist (child children fnd)
      (setq fnd
	    (or (rst-toc-insert-stn child buf style depth indent
				    (concat numbering (format num-fmt count))
				    keymap tgt-stn) fnd))
      (cl-incf count))))

;; FIXME refactoring: Use `rst-Stn-buffer' instead of `buf'.
(defun rst-toc-insert-stn (stn buf style depth indent numbering keymap tgt-stn)
  ;; testcover: ok.
  "In the current buffer at point insert STN in BUF into table of contents.
See `rst-toc-insert-tree' for STYLE, DEPTH and TGT-STN.  INDENT
is the indentation depth to use for STN.  NUMBERING is the prefix
numbering for STN.  See `rst-toc-insert-link' for KEYMAP."
  (when (or (not depth) (> depth 0))
    (cl-destructuring-bind
	(pfx add
	     &aux (fnd (when (and tgt-stn
				  (equal (rst-Stn-get-title-beginning stn)
					 (rst-Stn-get-title-beginning tgt-stn)))
			 (point))))
	(cond
	 ((eq style 'plain)
	  (list "" rst-toc-indent))
	 ((eq style 'fixed)
	  (list (concat numbering rst-toc-insert-number-separator)
		rst-toc-indent))
	 ((eq style 'aligned)
	  (list (concat numbering rst-toc-insert-number-separator)
		(+ (length numbering)
		   (length rst-toc-insert-number-separator))))
	 ((eq style 'listed)
	  (list (format "%c " (car rst-preferred-bullets)) 2)))
      ;; Indent using spaces so buffer characteristics like `indent-tabs-mode'
      ;; do not matter.
      (rst-toc-insert-link (concat (make-string indent ? ) pfx) stn buf keymap)
      (or (rst-toc-insert-children (rst-Stn-children stn) buf style
				   (when depth
				     (1- depth))
				   (+ indent add) numbering keymap tgt-stn)
	  fnd))))

(defun rst-toc-update ()
  ;; testcover: ok.
  "Automatically find the contents section of a document and update.
Updates the inserted TOC if present.  You can use this in your
file-write hook to always make it up-to-date automatically."
  (interactive)
  (save-match-data
    (save-excursion
      ;; Find and delete an existing comment after the first contents
      ;; directive.  Delete that region.
      (goto-char (point-min))
      ;; FIXME: Should accept indentation of the whole block.
      ;; We look for the following and the following only (in other words, if
      ;; your syntax differs, this won't work.).
      ;;
      ;;   .. contents:: [...anything here...]
      ;;      [:field: value]...
      ;;   ..
      ;;      XXXXXXXX
      ;;      XXXXXXXX
      ;;      [more lines]
      ;; FIXME: Works only for the first of these tocs.  There should be a
      ;;        fixed text after the comment such as "RST-MODE ELECTRIC TOC".
      ;;        May be parameters such as `max-level' should be appended.
      (let ((beg (re-search-forward
		  (1value
		   (rst-re "^" 'exm-sta "contents" 'dcl-tag ".*\n"
			   "\\(?:" 'hws-sta 'fld-tag ".*\n\\)*" 'exm-tag))
		  nil t))
	    fnd)
	(when
	    (and beg
		 (rst-forward-line-looking-at
		  1 'lin-end
                  (lambda (mtcd)
                    (unless mtcd
                      (rst-apply-indented-blocks
                       (point) (point-max) (current-indentation)
                       (lambda (count _in-first _in-sub in-super in-empty
                                 _relind)
                         (cond
                          ((or (> count 1) in-super))
                          ((not in-empty)
                           (setq fnd (line-end-position))
                           nil)))))
                    t)))
	  (when fnd
	    (delete-region beg fnd))
	  (goto-char beg)
	  (insert "\n    ")
	  ;; FIXME: Ignores an `max-level' given to the original
	  ;;        `rst-toc-insert'. `max-level' could be rendered to the first
	  ;;        line.
	  (rst-toc-insert)))))
  ;; Note: always return nil, because this may be used as a hook.
  nil)

;; FIXME: Updating the toc on saving would be nice. However, this doesn't work
;;        correctly:
;;
;;	  (add-hook 'write-contents-functions 'rst-toc-update-fun)
;;	  (defun rst-toc-update-fun ()
;;	    ;; Disable undo for the write file hook.
;;	    (let ((buffer-undo-list t)) (rst-toc-update) ))

;; Maintain an alias for compatibility.
(defalias 'rst-toc-insert-update 'rst-toc-update)

(defconst rst-toc-buffer-name "*Table of Contents*"
  "Name of the Table of Contents buffer.")

(defvar-local rst-toc-mode-return-wincfg nil
  "Window configuration to which to return when leaving the TOC.")

(defun rst-toc ()
  ;; testcover: ok.
  "Display a table of contents for current buffer.
Displays all section titles found in the current buffer in a
hierarchical list.  The resulting buffer can be navigated, and
selecting a section title moves the cursor to that section."
  (interactive)
  (rst-reset-section-caches)
  (let* ((wincfg (list (current-window-configuration) (point-marker)))
         (sectree (rst-all-stn))
 	 (target-stn (rst-stn-containing-point sectree))
	 (target-buf (current-buffer))
         (buf (get-buffer-create rst-toc-buffer-name))
	 target-pos)
    (with-current-buffer buf
      (let ((inhibit-read-only t))
        (rst-toc-mode)
        (delete-region (point-min) (point-max))
	;; FIXME: Could use a customizable style.
        (setq target-pos (rst-toc-insert-tree
			  sectree target-buf 'plain nil nil target-stn))))
    (display-buffer buf)
    (pop-to-buffer buf)
    (setq rst-toc-mode-return-wincfg wincfg)
    (goto-char (or target-pos (point-min)))))

;; Maintain an alias for compatibility.
(defalias 'rst-goto-section 'rst-toc-follow-link)

(defun rst-toc-follow-link (link-buf link-pnt kill)
  ;; testcover: ok.
  "Follow the link to the section at LINK-PNT in LINK-BUF.
LINK-PNT and LINK-BUF default to the point in the current buffer.
With prefix argument KILL a TOC buffer is destroyed.  Throw an
error if there is no working link at the given position."
  (interactive "i\nd\nP")
  (unless link-buf
    (setq link-buf (current-buffer)))
  ;; Do not catch errors from `rst-toc-get-link' because otherwise the error is
  ;; suppressed and invisible in interactive use.
  (let ((mrkr (rst-toc-get-link link-buf link-pnt)))
    (condition-case nil
	(rst-toc-mode-return kill)
      ;; Catch errors when not in `toc-mode'.
      (error nil))
    (pop-to-buffer (marker-buffer mrkr))
    (goto-char mrkr)
    ;; FIXME: Should be a customizable number of lines from beginning or end of
    ;;        window just like the argument to 'recenter'. It would be ideal if
    ;;        the adornment is always completely visible.
    (recenter 5)))

;; Maintain an alias for compatibility.
(defalias 'rst-toc-mode-goto-section 'rst-toc-mode-follow-link-kill)

;; FIXME: Cursor before or behind the list must be handled properly; before the
;;        list should jump to the top and behind the list to the last normal
;;        paragraph.
(defun rst-toc-mode-follow-link-kill ()
  ;; testcover: ok.
  "Follow the link to the section at point and kill the TOC buffer."
  (interactive)
  (rst-toc-follow-link (current-buffer) (point) t))

;; Maintain an alias for compatibility.
(defalias 'rst-toc-mode-mouse-goto 'rst-toc-mouse-follow-link)

(defun rst-toc-mouse-follow-link (event kill)
  ;; testcover: uncovered.
  "In `rst-toc' mode, go to the occurrence whose line you click on.
EVENT is the input event.  Kill TOC buffer if KILL."
  (interactive "e\ni")
  (rst-toc-follow-link (window-buffer (posn-window (event-end event)))
		       (posn-point (event-end event)) kill))

;; Maintain an alias for compatibility.
(defalias 'rst-toc-mode-mouse-goto-kill 'rst-toc-mode-mouse-follow-link-kill)

(defun rst-toc-mode-mouse-follow-link-kill (event)
  ;; testcover: uncovered.
  "Same as `rst-toc-mouse-follow-link', but kill TOC buffer as well.
EVENT is the input event."
  (interactive "e")
  (rst-toc-mouse-follow-link event t))

;; Maintain an alias for compatibility.
(defalias 'rst-toc-quit-window 'rst-toc-mode-return)

(defun rst-toc-mode-return (kill)
  ;; testcover: ok.
  "Leave the current TOC buffer and return to the previous environment.
With prefix argument KILL non-nil, kill the buffer instead of
burying it."
  (interactive "P")
  (unless rst-toc-mode-return-wincfg
    (error "Not in a `toc-mode' buffer"))
  (cl-destructuring-bind
      (wincfg pos
       &aux (toc-buf (current-buffer)))
      rst-toc-mode-return-wincfg
    (set-window-configuration wincfg)
    (goto-char pos)
    (if kill
	(kill-buffer toc-buf)
      (bury-buffer toc-buf))))

(defun rst-toc-mode-return-kill ()
  ;; testcover: uncovered.
  "Like `rst-toc-mode-return' but kill TOC buffer."
  (interactive)
  (rst-toc-mode-return t))

(defvar rst-toc-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map [mouse-1] #'rst-toc-mode-mouse-follow-link-kill)
    (define-key map [mouse-2] #'rst-toc-mouse-follow-link)
    (define-key map "\C-m" #'rst-toc-mode-follow-link-kill)
    (define-key map "f" #'rst-toc-mode-follow-link-kill)
    (define-key map "n" #'next-line)
    (define-key map "p" #'previous-line)
    (define-key map "q" #'rst-toc-mode-return)
    (define-key map "z" #'rst-toc-mode-return-kill)
    map)
  "Keymap for `rst-toc-mode'.")

(define-derived-mode rst-toc-mode special-mode "ReST-TOC"
  "Major mode for output from \\[rst-toc], the table-of-contents for the document.
\\{rst-toc-mode-map}"
  ;; FIXME: 'revert-buffer-function' must be defined so 'revert-buffer' works
  ;;        as expected for a special mode. In particular the referred buffer
  ;;        needs to be rescanned and the TOC must be updated accordingly.
  ;; FIXME: Should contain the name of the buffer this is the toc of.
  (setq header-line-format "Table of Contents"))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Section movement

;; FIXME testcover: Use `testcover'. Mark up a function with sufficient test
;;                  coverage by a comment tagged with `testcover' after the
;;                  `defun'. Then move this comment.

(defun rst-forward-section (offset)
  "Jump forward OFFSET section titles ending up at the start of the title line.
OFFSET defaults to 1 and may be negative to move backward.  An
OFFSET of 0 does not move unless point is inside a title.  Go to
end or beginning of buffer if no more section titles in the desired
direction."
  (interactive "p")
  (rst-reset-section-caches)
  (let* ((ttls (rst-all-ttls))
	 (count (length ttls))
	 (pnt (point))
	 (contained nil) ; Title contains point (or is after point otherwise).
         (found (or (cl-position-if
		     ;; Find a title containing or after point.
                     (lambda (ttl)
                       (let ((cmp (rst-Ttl-contains ttl pnt)))
                         (cond
                          ((= cmp 0) ; Title contains point.
                           (setq contained t)
                           t)
                          ((> cmp 0) ; Title after point.
                           t))))
		     ttls)
		    ;; Point after all titles.
		    count))
	 (target (+ found offset
		    ;; If point is in plain text found title is already one
		    ;; step forward.
		    (if (and (not contained) (>= offset 0)) -1 0))))
    (goto-char (cond
		((< target 0)
		 (point-min))
		((>= target count)
		 (point-max))
		((and (not contained) (= offset 0))
		 ;; Point not in title and should not move - do not move.
		 pnt)
		((rst-Ttl-get-title-beginning (nth target ttls)))))))

(defun rst-backward-section (offset)
  "Like `rst-forward-section', except move backward by OFFSET."
  (interactive "p")
  (rst-forward-section (- offset)))

;; FIXME: What is `allow-extend' for? See `mark-paragraph' for an explanation.
(defun rst-mark-section (&optional count allow-extend)
  "Select COUNT sections around point.
Mark following sections for positive COUNT or preceding sections
for negative COUNT."
  ;; Cloned from mark-paragraph.
  (interactive "p\np")
  (unless count (setq count 1))
  (when (zerop count)
    (error "Cannot mark zero sections"))
  (cond ((and allow-extend
	      (or (and (eq last-command this-command) (mark t))
		  (use-region-p)))
	 (set-mark
	  (save-excursion
	    (goto-char (mark))
	    (rst-forward-section count)
	    (point))))
	(t
	 (rst-forward-section count)
	 (push-mark nil t t)
	 (rst-forward-section (- count)))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Indentation

(defun rst-find-leftmost-column (beg end)
  "Return the leftmost column spanned by region BEG to END.
The line containing the start of the region is always considered
spanned.  If the region ends at the beginning of a line this line
is not considered spanned, otherwise it is spanned."
  (let (mincol)
    (save-match-data
      (save-excursion
	(goto-char beg)
	(1value
	 (rst-forward-line-strict 0))
	(while (< (point) end)
	  (unless (looking-at (rst-re 'lin-end))
	    (setq mincol (if mincol
			     (min mincol (current-indentation))
			   (current-indentation))))
	  (rst-forward-line-strict 1 end)))
      mincol)))

;; FIXME: At the moment only block comments with leading empty comment line are
;;        supported.  Comment lines with leading comment markup should be also
;;        supported.  May be a customizable option could control which style to
;;        prefer.

(defgroup rst-indent nil "Settings for indentation in reStructuredText.

In reStructuredText indentation points are usually determined by
preceding lines.  Sometimes the syntax allows arbitrary indentation
points such as where to start the first line following a directive.
These indentation widths can be customized here."
  :group 'rst
  :package-version '(rst . "1.1.0"))

(define-obsolete-variable-alias
  'rst-shift-basic-offset 'rst-indent-width "rst 1.0.0")
(defcustom rst-indent-width 2
  "Indentation when there is no more indentation point given."
  :group 'rst-indent
  :type '(integer))

(defcustom rst-indent-field 3
  "Indentation for first line after a field or 0 to always indent for content."
  :group 'rst-indent
  :package-version '(rst . "1.1.0")
  :type '(integer))

(defcustom rst-indent-literal-normal 3
  "Default indentation for literal block after a markup on an own line."
  :group 'rst-indent
  :package-version '(rst . "1.1.0")
  :type '(integer))

(defcustom rst-indent-literal-minimized 2
  "Default indentation for literal block after a minimized markup."
  :group 'rst-indent
  :package-version '(rst . "1.1.0")
  :type '(integer))

(defcustom rst-indent-comment 3
  "Default indentation for first line of a comment."
  :group 'rst-indent
  :package-version '(rst . "1.1.0")
  :type '(integer))

;; FIXME: Must consider other tabs:
;;        * Line blocks
;;        * Definition lists
;;        * Option lists
(defun rst-line-tabs ()
  "Return tabs of the current line or nil for no tab.
The list is sorted so the tab where writing continues most likely
is the first one.  Each tab is of the form (COLUMN . INNER).
COLUMN is the column of the tab.  INNER is non-nil if this is an
inner tab.  I.e. a tab which does come from the basic indentation
and not from inner alignment points."
  (save-excursion
    (rst-forward-line-strict 0)
    (save-match-data
      (unless (looking-at (rst-re 'lin-end))
	(back-to-indentation)
	;; Current indentation is always the least likely tab.
	(let ((tabs (list (list (point) 0 nil)))) ; (POINT OFFSET INNER)
	  ;; Push inner tabs more likely to continue writing.
	  (cond
	   ;; Item.
	   ((looking-at (rst-re '(:grp itmany-tag hws-sta) '(:grp "\\S ") "?"))
	    (when (match-string 2)
	      (push (list (match-beginning 2) 0 t) tabs)))
	   ;; Field.
	   ((looking-at (rst-re '(:grp fld-tag) '(:grp hws-tag)
				'(:grp "\\S ") "?"))
	    (unless (zerop rst-indent-field)
	      (push (list (match-beginning 1) rst-indent-field t) tabs))
	    (if (match-string 3)
		(push (list (match-beginning 3) 0 t) tabs)
	      (if (zerop rst-indent-field)
		  (push (list (match-end 2)
			      (if (string= (match-string 2) "") 1 0)
			      t)
                        tabs))))
	   ;; Directive.
	   ((looking-at (rst-re 'dir-sta-3 '(:grp "\\S ") "?"))
	    (push (list (match-end 1) 0 t) tabs)
	    (unless (string= (match-string 2) "")
	      (push (list (match-end 2) 0 t) tabs))
	    (when (match-string 4)
	      (push (list (match-beginning 4) 0 t) tabs)))
	   ;; Footnote or citation definition.
	   ((looking-at (rst-re 'fnc-sta-2 '(:grp "\\S ") "?"))
	    (push (list (match-end 1) 0 t) tabs)
	    (when (match-string 3)
	      (push (list (match-beginning 3) 0 t) tabs)))
	   ;; Comment.
	   ((looking-at (rst-re 'cmt-sta-1))
	    (push (list (point) rst-indent-comment t) tabs)))
	  ;; Start of literal block.
	  (when (looking-at (rst-re 'lit-sta-2))
	    (cl-destructuring-bind (point offset _inner) (car tabs)
	      (push (list point
			  (+ offset
			     (if (match-string 1)
				 rst-indent-literal-minimized
			       rst-indent-literal-normal))
			  t)
                    tabs)))
	  (mapcar (cl-function
		   (lambda ((point offset inner))
		    (goto-char point)
		    (cons (+ (current-column) offset) inner)))
		  tabs))))))

(defun rst-compute-tabs (pt)
  "Build the list of possible tabs for all lines above.
Search backwards from point PT to build the list of possible tabs.
Return a list of tabs sorted by likeliness to continue writing
like `rst-line-tabs'.  Nearer lines have generally a higher
likeliness than farther lines.  Return nil if no tab is found in
the text above."
  ;; FIXME: See test 'indent-for-tab-command-BUGS'.
  (save-excursion
    (goto-char pt)
    (let (leftmost ; Leftmost column found so far.
	  innermost ; Leftmost column for inner tab.
	  tablist)
      (while (and (rst-forward-line-strict -1)
		  (or (not leftmost)
		      (> leftmost 0)))
	(let ((tabs (rst-line-tabs)))
	  (when tabs
	    (let ((leftcol (apply #'min (mapcar #'car tabs))))
	      ;; Consider only lines indented less or same if not INNERMOST.
	      (when (or (not leftmost)
			(< leftcol leftmost)
			(and (not innermost) (= leftcol leftmost)))
		(rst-destructuring-dolist ((column &rest inner) tabs)
		  (when (or
			 (and (not inner)
			      (or (not leftmost)
				  (< column leftmost)))
			 (and inner
			      (or (not innermost)
				  (< column innermost))))
		    (setq tablist (cl-adjoin column tablist))))
		(setq innermost (if (cl-some #'cdr tabs) ; Has inner.
				    leftcol
				  innermost))
		(setq leftmost leftcol))))))
      (nreverse tablist))))

(defun rst-indent-line (&optional dflt)
  "Indent current line to next best reStructuredText tab.
The next best tab is taken from the tab list returned by
`rst-compute-tabs' which is used in a cyclic manner.  If the
current indentation does not end on a tab use the first one.  If
the current indentation is on a tab use the next tab.  This allows
a repeated use of \\[indent-for-tab-command] to cycle through all
possible tabs.  If no indentation is possible return `noindent' or
use DFLT.  Return the indentation indented to.  When point is in
indentation it ends up at its end.  Otherwise the point is kept
relative to the content."
  (let* ((pt (point-marker))
	 (cur (current-indentation))
	 (clm (current-column))
	 (tabs (rst-compute-tabs (point)))
	 (fnd (cl-position cur tabs :test #'equal))
	 ind)
    (if (and (not tabs) (not dflt))
	'noindent
      (if (not tabs)
	  (setq ind dflt)
	(if (not fnd)
	    (setq fnd 0)
	  (setq fnd (1+ fnd))
	  (if (>= fnd (length tabs))
	      (setq fnd 0)))
	(setq ind (nth fnd tabs)))
      (indent-line-to ind)
      (if (> clm cur)
	  (goto-char pt))
      (set-marker pt nil)
      ind)))

(defun rst-shift-region (beg end cnt)
  "Shift region BEG to END by CNT tabs.
Shift by one tab to the right (CNT > 0) or left (CNT < 0) or
remove all indentation (CNT = 0).  A tab is taken from the text
above.  If no suitable tab is found `rst-indent-width' is used."
  (interactive "r\np")
  (let ((tabs (sort (rst-compute-tabs beg)
                    (lambda (x y)
                      (<= x y))))
	(leftmostcol (rst-find-leftmost-column beg end)))
    (when (or (> leftmostcol 0) (> cnt 0))
      ;; Apply the indent.
      (indent-rigidly
       beg end
       (if (zerop cnt)
	   (- leftmostcol)
	 ;; Find the next tab after the leftmost column.
	 (let* ((cmp (if (> cnt 0) #'> #'<))
		(tabs (if (> cnt 0) tabs (reverse tabs)))
		(len (length tabs))
		(dir (cl-signum cnt)) ; Direction to take.
		(abs (abs cnt)) ; Absolute number of steps to take.
		;; Get the position of the first tab beyond leftmostcol.
                (fnd (cl-position-if (lambda (elt)
                                       (funcall cmp elt leftmostcol))
                                      tabs))
		;; Virtual position of tab.
		(pos (+ (or fnd len) (1- abs)))
		(tab (if (< pos len)
			 ;; Tab exists - use it.
			 (nth pos tabs)
		       ;; Column needs to be computed.
		       (let ((col (+ (or (car (last tabs)) leftmostcol)
				     ;; Base on last known column.
				     (* (- pos (1- len)) ; Distance left.
					dir ; Direction to take.
					rst-indent-width))))
			 (if (< col 0) 0 col)))))
	   (- tab leftmostcol)))))))

;; FIXME: A paragraph with an (incorrectly) indented second line is not filled
;;        correctly::
;;
;;          Some start
;;            continued wrong
(defun rst-adaptive-fill ()
  "Return fill prefix found at point.
Value for `adaptive-fill-function'."
  (save-match-data
    (let ((fnd (if (looking-at adaptive-fill-regexp)
		   (match-string-no-properties 0))))
      (if (save-match-data
	    (not (string-match comment-start-skip fnd)))
	  ;; An non-comment prefix is fine.
	  fnd
	;; Matches a comment - return whitespace instead.
	(make-string (-
		      (save-excursion
			(goto-char (match-end 0))
			(current-column))
		      (save-excursion
			(goto-char (match-beginning 0))
			(current-column))) ? )))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Comments

(defun rst-comment-line-break (&optional soft)
  "Break line and indent, continuing reStructuredText comment if within one.
Value for `comment-line-break-function'.  If SOFT use soft
newlines as mandated by `comment-line-break-function'."
  (if soft
      (insert-and-inherit ?\n)
    (newline 1))
  (save-excursion
    (forward-char -1)
    (delete-horizontal-space))
  (delete-horizontal-space)
  (let ((tabs (rst-compute-tabs (point))))
    (when tabs
      (indent-line-to (car tabs)))))

(defun rst-comment-indent ()
  "Return indentation for current comment line."
  (car (rst-compute-tabs (point))))

(defun rst-comment-insert-comment ()
  "Insert a comment in the current line."
  (rst-indent-line 0)
  (insert comment-start))

(defun rst-comment-region (beg end &optional arg)
  "Comment or uncomment the current region.
Region is from BEG to END.  Uncomment if ARG."
  (save-excursion
    (if (consp arg)
	(rst-uncomment-region beg end arg)
      (goto-char beg)
      (rst-forward-line-strict 0)
      (let ((ind (current-indentation))
	    (bol (point)))
	(indent-rigidly bol end rst-indent-comment)
	(goto-char bol)
	(open-line 1)
	(indent-line-to ind)
	(insert (comment-string-strip comment-start t t))))))

(defun rst-uncomment-region (beg end &optional _arg)
  "Uncomment the current region.
Region is from BEG to END.  _ARG is ignored."
  (save-excursion
    (goto-char beg)
    (rst-forward-line-strict 0)
    (let ((bol (point)))
      (rst-forward-line-strict 1 end)
      (indent-rigidly (point) end (- rst-indent-comment))
      (goto-char bol)
      (rst-delete-entire-line 0))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Apply to indented block

;; FIXME: These next functions should become part of a larger effort to redo
;;        the bullets in bulleted lists.  The enumerate would just be one of
;;        the possible outputs.
;;
;; FIXME: We need to do the enumeration removal as well.

(defun rst-apply-indented-blocks (beg end ind fun)
  "Apply FUN to all lines from BEG to END in blocks indented to IND.
The first indented block starts with the first non-empty line
containing or after BEG and indented to IND.  After the first
line the indented block may contain more lines with same
indentation (the paragraph) followed by empty lines and lines
more indented (the sub-blocks).  A following line indented to IND
starts the next paragraph.  A non-empty line with less
indentation than IND terminates the current paragraph.  FUN is
applied to each line like this

  (FUN COUNT IN-FIRST IN-SUB IN-SUPER IN-EMPTY RELIND)

COUNT is 0 before the first paragraph and increments for every
paragraph found on level IND.  IN-FIRST is non-nil if this is the
first line of such a paragraph.  IN-SUB is non-nil if this line
is part of a sub-block while IN-SUPER is non-nil if this line is
part of a less indented block (super-block).  IN-EMPTY is non-nil
if this line is empty where an empty line is considered being
part of the previous block.  RELIND is nil for an empty line, 0
for a line indented to IND, and the positive or negative number
of columns more or less indented otherwise.  When FUN is called
point is immediately behind indentation of that line.  FUN may
change everything as long as a marker at END and at the beginning
of the following line is handled correctly by the change.  A
non-nil return value from FUN breaks the loop and is returned.
Otherwise return nil."
  (let ((endm (copy-marker end t))
	(count 0) ; Before first indented block.
	(nxt (when (< beg end)
	       (copy-marker beg t)))
	(broken t)
	in-sub in-super stop)
    (save-match-data
      (save-excursion
	(while (and (not stop) nxt)
	  (set-marker
	   (goto-char nxt) nil)
	  (setq nxt (save-excursion
		      ;; FIXME refactoring: Replace `(forward-line)
		      ;;                    (back-to-indentation)` by
		      ;;                    `(forward-to-indentation)`
		      (when (and (rst-forward-line-strict 1 endm)
				 (< (point) endm))
			(copy-marker (point) t))))
	  (back-to-indentation)
	  (let ((relind (- (current-indentation) ind))
		(in-empty (looking-at (rst-re 'lin-end)))
		in-first)
	    (cond
	     (in-empty
	      (setq relind nil))
	     ((< relind 0)
	      (setq in-sub nil)
	      (setq in-super t))
	     ((> relind 0)
	      (setq in-sub t)
	      (setq in-super nil))
	     (t ; Non-empty line in indented block.
	      (when (or broken in-sub in-super)
		(setq in-first t)
		(cl-incf count))
	      (setq in-sub nil)
	      (setq in-super nil)))
	    (save-excursion
	      (setq
	       stop
	       (funcall fun count in-first in-sub in-super in-empty relind)))
	    (setq broken in-empty)))
	(set-marker endm nil)
	stop))))

(defun rst-enumerate-region (beg end all)
  "Add enumeration to all the leftmost paragraphs in the given region.
The region is specified between BEG and END.  With ALL,
do all lines instead of just paragraphs."
  (interactive "r\nP")
  (let ((enum 0)
	(indent ""))
    (rst-apply-indented-blocks
     beg end (rst-find-leftmost-column beg end)
     (lambda (count in-first in-sub in-super in-empty _relind)
       (cond
        (in-empty)
        (in-super)
        ((zerop count))
        (in-sub
         (insert indent))
        ((or in-first all)
         (let ((tag (format "%d. " (cl-incf enum))))
           (setq indent (make-string (length tag) ? ))
           (insert tag)))
        (t
         (insert indent)))
       nil))))

;; FIXME: Does not deal with deeper indentation - although
;;        `rst-apply-indented-blocks' could.
(defun rst-bullet-list-region (beg end all)
  "Add bullets to all the leftmost paragraphs in the given region.
The region is specified between BEG and END.  With ALL,
do all lines instead of just paragraphs."
  (interactive "r\nP")
  (unless rst-preferred-bullets
    (error "No preferred bullets defined"))
  (let* ((bul (format "%c " (car rst-preferred-bullets)))
	 (indent (make-string (length bul) ? )))
    (rst-apply-indented-blocks
     beg end (rst-find-leftmost-column beg end)
     (lambda (count in-first in-sub in-super in-empty _relind)
       (cond
        (in-empty)
        (in-super)
        ((zerop count))
        (in-sub
         (insert indent))
        ((or in-first all)
         (insert bul))
        (t
         (insert indent)))
       nil))))

;; FIXME: Does not deal with a varying number of digits appropriately.
;; FIXME: Does not deal with multiple levels independently.
;; FIXME: Does not indent a multiline item correctly.
(defun rst-convert-bullets-to-enumeration (beg end)
  "Convert the bulleted and enumerated items in the region to enumerated lists.
Renumber as necessary.  Region is from BEG to END."
  (interactive "r")
  (let ((count 1))
    (save-match-data
      (save-excursion
	(dolist (marker (mapcar
			 (cl-function
			  (lambda ((pnt &rest clm))
			    (copy-marker pnt)))
			 (rst-find-begs beg end 'itmany-beg-1)))
	  (set-marker
	   (goto-char marker) nil)
	  (looking-at (rst-re 'itmany-beg-1))
	  (replace-match (format "%d." count) nil nil nil 1)
	  (cl-incf count))))))

(defun rst-line-block-region (beg end &optional with-empty)
  "Add line block prefixes for a region.
Region is from BEG to END.  With WITH-EMPTY prefix empty lines too."
  (interactive "r\nP")
  (let ((ind (rst-find-leftmost-column beg end)))
    (rst-apply-indented-blocks
     beg end ind
     (lambda (_count _in-first _in-sub in-super in-empty _relind)
       (when (and (not in-super) (or with-empty (not in-empty)))
         (move-to-column ind t)
         (insert "| "))
       nil))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Font lock

;; FIXME: The obsolete variables need to disappear.

;; The following versions have been done inside Emacs and should not be
;; replaced by `:package-version' attributes until a change.

(defgroup rst-faces nil "Faces used in Rst Mode."
  :group 'rst
  :group 'faces
  :version "21.1")

(defface rst-block '((t :inherit font-lock-keyword-face))
  "Face used for all syntax marking up a special block."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-block-face 'rst-block
  "All syntax marking up a special block."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-block-face
                        "customize the face `rst-block' instead."
                        "24.1")

(defface rst-external '((t :inherit font-lock-type-face))
  "Face used for field names and interpreted text."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-external-face 'rst-external
  "Field names and interpreted text."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-external-face
                        "customize the face `rst-external' instead."
                        "24.1")

(defface rst-definition '((t :inherit font-lock-function-name-face))
  "Face used for all other defining constructs."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-definition-face 'rst-definition
  "All other defining constructs."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-definition-face
                        "customize the face `rst-definition' instead."
                        "24.1")

(defface rst-directive '((t :inherit font-lock-builtin-face))
  "Face used for directives and roles."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-directive-face 'rst-directive
  "Directives and roles."
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-directive-face
                        "customize the face `rst-directive' instead."
                        "24.1")

(defface rst-comment '((t :inherit font-lock-comment-face))
  "Face used for comments."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-comment-face 'rst-comment
  "Comments."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-comment-face
                        "customize the face `rst-comment' instead."
                        "24.1")

(defface rst-emphasis1 '((t :inherit italic))
  "Face used for simple emphasis."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-emphasis1-face 'rst-emphasis1
  "Simple emphasis."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-emphasis1-face
                        "customize the face `rst-emphasis1' instead."
                        "24.1")

(defface rst-emphasis2 '((t :inherit bold))
  "Face used for double emphasis."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-emphasis2-face 'rst-emphasis2
  "Double emphasis."
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-emphasis2-face
                        "customize the face `rst-emphasis2' instead."
                        "24.1")

(defface rst-literal '((t :inherit font-lock-string-face))
  "Face used for literal text."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-literal-face 'rst-literal
  "Literal text."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-literal-face
                        "customize the face `rst-literal' instead."
                        "24.1")

(defface rst-reference '((t :inherit font-lock-variable-name-face))
  "Face used for references to a definition."
  :version "24.1"
  :group 'rst-faces)

(defcustom rst-reference-face 'rst-reference
  "References to a definition."
  :version "24.1"
  :group 'rst-faces
  :type '(face))
(make-obsolete-variable 'rst-reference-face
                        "customize the face `rst-reference' instead."
                        "24.1")

(defface rst-transition '((t :inherit font-lock-keyword-face))
  "Face used for a transition."
  :package-version '(rst . "1.3.0")
  :group 'rst-faces)

(defface rst-adornment '((t :inherit font-lock-keyword-face))
  "Face used for the adornment of a section header."
  :package-version '(rst . "1.3.0")
  :group 'rst-faces)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(dolist (var '(rst-level-face-max rst-level-face-base-color
				  rst-level-face-base-light
				  rst-level-face-format-light
				  rst-level-face-step-light
				  rst-level-1-face
				  rst-level-2-face
				  rst-level-3-face
				  rst-level-4-face
				  rst-level-5-face
				  rst-level-6-face))
  (make-obsolete-variable var "customize the faces `rst-level-*' instead."
			  "24.3"))

;; Define faces for the first 6 levels. More levels are possible, however.
(defface rst-level-1 '((((background light)) (:background "grey85"))
		       (((background dark)) (:background "grey15")))
  "Default face for section title text at level 1."
  :package-version '(rst . "1.4.0"))

(defface rst-level-2 '((((background light)) (:background "grey78"))
		       (((background dark)) (:background "grey22")))
  "Default face for section title text at level 2."
  :package-version '(rst . "1.4.0"))

(defface rst-level-3 '((((background light)) (:background "grey71"))
		       (((background dark)) (:background "grey29")))
  "Default face for section title text at level 3."
  :package-version '(rst . "1.4.0"))

(defface rst-level-4 '((((background light)) (:background "grey64"))
		       (((background dark)) (:background "grey36")))
  "Default face for section title text at level 4."
  :package-version '(rst . "1.4.0"))

(defface rst-level-5 '((((background light)) (:background "grey57"))
		       (((background dark)) (:background "grey43")))
  "Default face for section title text at level 5."
  :package-version '(rst . "1.4.0"))

(defface rst-level-6 '((((background light)) (:background "grey50"))
		       (((background dark)) (:background "grey50")))
  "Default face for section title text at level 6."
  :package-version '(rst . "1.4.0"))

(defcustom rst-adornment-faces-alist
  '((t . rst-transition)
    (nil . rst-adornment)
    (1 . rst-level-1)
    (2 . rst-level-2)
    (3 . rst-level-3)
    (4 . rst-level-4)
    (5 . rst-level-5)
    (6 . rst-level-6))
    "Faces for the various adornment types.
Key is a number (for the section title text of that level
starting with 1), t (for transitions) or nil (for section title
adornment).  If you need levels beyond 6 you have to define faces
of your own."
  :group 'rst-faces
  :type '(alist
	  :key-type
	  (choice
	   (integer :tag "Section level")
	   (const :tag "transitions" t)
	   (const :tag "section title adornment" nil))
	  :value-type (face)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar rst-font-lock-keywords
  ;; The reST-links in the comments below all relate to sections in
  ;; https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html.
  `(;; FIXME: Block markup is not recognized in blocks after explicit markup
    ;;        start.

    ;; Simple `Body Elements`_
    ;; `Bullet Lists`_
    ;; FIXME: A bullet directly after a field name is not recognized.
    (,(rst-re 'lin-beg '(:grp bul-sta))
     1 rst-block-face)
    ;; `Enumerated Lists`_
    (,(rst-re 'lin-beg '(:grp enmany-sta))
     1 rst-block-face)
    ;; `Definition Lists`_
    ;; FIXME: missing.
    ;; `Field Lists`_
    (,(rst-re 'lin-beg '(:grp fld-tag) 'bli-sfx)
     1 rst-external-face)
    ;; `Option Lists`_
    (,(rst-re 'lin-beg '(:grp opt-tag (:shy optsep-tag opt-tag) "*")
	      '(:alt "$" (:seq hws-prt "\\{2\\}")))
     1 rst-block-face)
    ;; `Line Blocks`_
    ;; Only for lines containing no more bar - to distinguish from tables.
    (,(rst-re 'lin-beg '(:grp "|" bli-sfx) "[^|\n]*$")
     1 rst-block-face)

    ;; `Tables`_
    ;; FIXME: missing

    ;; All the `Explicit Markup Blocks`_
    ;; `Footnotes`_ / `Citations`_
    (,(rst-re 'lin-beg 'fnc-sta-2)
     (1 rst-definition-face)
     (2 rst-definition-face))
    ;; `Directives`_ / `Substitution Definitions`_
    (,(rst-re 'lin-beg 'dir-sta-3)
     (1 rst-directive-face)
     (2 rst-definition-face)
     (3 rst-directive-face))
    ;; `Hyperlink Targets`_
    (,(rst-re 'lin-beg
	      '(:grp exm-sta "_" (:alt
				  (:seq "`" ilcbkqdef-tag "`")
				  (:seq (:alt "[^:\\\n]" "\\\\.") "+")) ":")
	      'bli-sfx)
     1 rst-definition-face)
    (,(rst-re 'lin-beg '(:grp "__") 'bli-sfx)
     1 rst-definition-face)

    ;; All `Inline Markup`_
    ;; Most of them may be multiline though this is uninteresting.

    ;; FIXME: Condition 5 preventing fontification of e.g. "*" not implemented
    ;;        `Strong Emphasis`_.
    (,(rst-re 'ilm-pfx '(:grp "\\*\\*" ilcast-tag "\\*\\*") 'ilm-sfx)
     1 rst-emphasis2-face)
    ;; `Emphasis`_
    (,(rst-re 'ilm-pfx '(:grp "\\*" ilcast-tag "\\*") 'ilm-sfx)
     1 rst-emphasis1-face)
    ;; `Inline Literals`_
    (,(rst-re 'ilm-pfx '(:grp "``" ilcbkq-tag "``") 'ilm-sfx)
     1 rst-literal-face)
    ;; `Inline Internal Targets`_
    (,(rst-re 'ilm-pfx '(:grp "_`" ilcbkq-tag "`") 'ilm-sfx)
     1 rst-definition-face)
    ;; `Hyperlink References`_
    ;; FIXME: `Embedded URIs and Aliases`_ not considered.
    ;; FIXME: Directly adjacent marked up words are not fontified correctly
    ;;        unless they are not separated by two spaces: foo_ bar_.
    (,(rst-re 'ilm-pfx '(:grp (:alt (:seq "`" ilcbkq-tag "`")
				    (:seq "\\sw" (:alt "\\sw" "-") "+\\sw"))
			      "__?") 'ilm-sfx)
     1 rst-reference-face)
    ;; `Interpreted Text`_
    (,(rst-re 'ilm-pfx '(:grp (:shy ":" sym-tag ":") "?")
	      '(:grp "`" ilcbkq-tag "`")
	      '(:grp (:shy ":" sym-tag ":") "?") 'ilm-sfx)
     (1 rst-directive-face)
     (2 rst-external-face)
     (3 rst-directive-face))
    ;; `Footnote References`_ / `Citation References`_
    (,(rst-re 'ilm-pfx '(:grp fnc-tag "_") 'ilm-sfx)
     1 rst-reference-face)
    ;; `Substitution References`_
    ;; FIXME: References substitutions like |this|_ or |this|__ are not
    ;;        fontified correctly.
    (,(rst-re 'ilm-pfx '(:grp sub-tag) 'ilm-sfx)
     1 rst-reference-face)
    ;; `Standalone Hyperlinks`_
    ;; FIXME: This takes it easy by using a whitespace as delimiter.
    (,(rst-re 'ilm-pfx '(:grp uri-tag ":\\S +") 'ilm-sfx)
     1 rst-definition-face)
    (,(rst-re 'ilm-pfx '(:grp sym-tag "@" sym-tag ) 'ilm-sfx)
     1 rst-definition-face)

    ;; Do all block fontification as late as possible so 'append works.

    ;; Sections_ / Transitions_
    ;; For sections this is multiline.
    (,(rst-re 'ado-beg-2-1)
     (rst-font-lock-handle-adornment-matcher
      (rst-font-lock-handle-adornment-pre-match-form
       (match-string-no-properties 1) (match-end 1))
      nil
      (1 (cdr (assoc nil rst-adornment-faces-alist)) append t)
      (2 (cdr (assoc rst-font-lock-adornment-level
		     rst-adornment-faces-alist)) append t)
      (3 (cdr (assoc nil rst-adornment-faces-alist)) append t)))

    ;; FIXME: FACESPEC could be used instead of ordinary faces to set
    ;;        properties on comments and literal blocks so they are *not*
    ;;        inline fontified.  See (elisp)Search-based Fontification.

    ;; FIXME: And / or use `syntax-propertize' functions as in `octave-mod.el'
    ;;        and other V24 modes.  May make `font-lock-extend-region'
    ;;        superfluous.

    ;; `Comments`_
    ;; This is multiline.
    (,(rst-re 'lin-beg 'cmt-sta-1)
     (1 rst-comment-face)
     (rst-font-lock-find-unindented-line-match
      (rst-font-lock-find-unindented-line-limit (match-end 1))
      nil
      (0 rst-comment-face append)))
    (,(rst-re 'lin-beg '(:grp exm-tag) '(:grp hws-tag) "$")
     (1 rst-comment-face)
     (2 rst-comment-face)
     (rst-font-lock-find-unindented-line-match
      (rst-font-lock-find-unindented-line-limit 'next)
      nil
      (0 rst-comment-face append)))

    ;; FIXME: This is not rendered as comment::
    ;;        .. .. list-table::
    ;;              :stub-columns: 1
    ;;              :header-rows: 1

    ;; FIXME: This is rendered wrong::
    ;;
    ;; 	 xxx yyy::
    ;;
    ;; 	 			----|> KKKKK <|----
    ;; 	 		       /	     	    \
    ;; 	    -|> AAAAAAAAAAPPPPPP <|-   	       	 -|> AAAAAAAAAABBBBBBB <|-
    ;; 	    |			   |	     	 |     	       	       	 |
    ;; 	    |			   |		 |			 |
    ;; 	    PPPPPP     PPPPPPDDDDDDD             BBBBBBB     PPPPPPBBBBBBB
    ;;
    ;; Indentation needs to be taken from the line with the ``::`` and not from
    ;; the first content line.

    ;; `Indented Literal Blocks`_
    ;; This is multiline.
    (,(rst-re 'lin-beg 'lit-sta-2)
     (2 rst-block-face)
     (rst-font-lock-find-unindented-line-match
      (rst-font-lock-find-unindented-line-limit t)
      nil
      (0 rst-literal-face append)))

    ;; FIXME: `Quoted Literal Blocks`_ missing.
    ;; This is multiline.

    ;; `Doctest Blocks`_
    ;; FIXME: This is wrong according to the specification:
    ;;
    ;;   Doctest blocks are text blocks which begin with ">>> ", the Python
    ;;   interactive interpreter main prompt, and end with a blank line.
    ;;   Doctest blocks are treated as a special case of literal blocks,
    ;;   without requiring the literal block syntax. If both are present, the
    ;;   literal block syntax takes priority over Doctest block syntax:
    ;;
    ;;   This is an ordinary paragraph.
    ;;
    ;;   >>> print 'this is a Doctest block'
    ;;   this is a Doctest block
    ;;
    ;;   The following is a literal block::
    ;;
    ;;       >>> This is not recognized as a doctest block by
    ;;       reStructuredText.  It *will* be recognized by the doctest
    ;;       module, though!
    ;;
    ;;   Indentation is not required for doctest blocks.
    (,(rst-re 'lin-beg '(:grp (:alt ">>>" ell-tag)) '(:grp ".+"))
     (1 rst-block-face)
     (2 rst-literal-face)))
  "Keywords to highlight in rst mode.")

(defvar font-lock-beg)
(defvar font-lock-end)

(defun rst-font-lock-extend-region ()
  "Extend the font-lock region if it might be in a multi-line construct.
Return non-nil if so.  Font-lock region is from `font-lock-beg'
to `font-lock-end'."
  (let ((r (rst-font-lock-extend-region-internal font-lock-beg font-lock-end)))
    (when r
      (setq font-lock-beg (car r))
      (setq font-lock-end (cdr r))
      t)))

(defun rst-font-lock-extend-region-internal (beg end)
  "Check the region BEG / END for being in the middle of a multi-line construct.
Return nil if not or a cons with new values for BEG / END."
  (let ((nbeg (rst-font-lock-extend-region-extend beg -1))
	(nend (rst-font-lock-extend-region-extend end 1)))
    (if (or nbeg nend)
	(cons (or nbeg beg) (or nend end)))))

;; FIXME refactoring: Use `rst-forward-line-strict' instead.
(defun rst-forward-line (&optional n)
  "Like `forward-line' but always end up in column 0 and return accordingly.
Move N lines forward just as `forward-line'."
  (let ((left (forward-line n)))
    (if (bolp)
	left
      ;; FIXME: This may move back for positive n - is this desired?
      (forward-line 0)
      (- left (cl-signum n)))))

;; FIXME: If a single line is made a section header by `rst-adjust' the header
;;        is not always fontified immediately.
(defun rst-font-lock-extend-region-extend (pt dir)
  "Extend the region starting at point PT and extending in direction DIR.
Return extended point or nil if not moved."
  ;; There are many potential multiline constructs but there are two groups
  ;; which are really relevant. The first group consists of
  ;;
  ;; * comment lines without leading explicit markup tag and
  ;;
  ;; * literal blocks following "::"
  ;;
  ;; which are both indented. Thus indentation is the first thing recognized
  ;; here. The second criteria is an explicit markup tag which may be a comment
  ;; or a double colon at the end of a line.
  ;;
  ;; The second group consists of the adornment cases.
  (if (not (get-text-property pt 'font-lock-multiline))
      ;; Move only if we don't start inside a multiline construct already.
      (save-match-data
	(save-excursion
	  (let ( ; Non-empty non-indented line, explicit markup tag or literal
	         ; block tag.
		(stop-re (rst-re '(:alt "[^ \t\n]"
					(:seq hws-tag exm-tag)
					(:seq ".*" dcl-tag lin-end)))))
	    ;; The comments below are for dir == -1 / dir == 1.
	    (goto-char pt)
	    (rst-forward-line-strict 0)
	    (setq pt (point))
	    (while (and (not (looking-at stop-re))
			(zerop (rst-forward-line dir)))) ; try previous / next
						         ; line if it exists.
	    (if (looking-at (rst-re 'ado-beg-2-1)) ; may be an underline /
						   ; overline.
		(if (zerop (rst-forward-line dir))
		    (if (looking-at (rst-re 'ttl-beg-1)) ; title found, i.e.
						         ; underline / overline
						         ; found.
			(if (zerop (rst-forward-line dir))
			    (if (not
				 (looking-at (rst-re 'ado-beg-2-1))) ; no
								     ; overline
								     ; /
								     ; underline.
				(rst-forward-line (- dir)))) ; step back to
							     ; title /
							     ; adornment.
		      (if (< dir 0) ; keep downward adornment.
			  (rst-forward-line (- dir))))) ; step back to adornment.
	      (if (looking-at (rst-re 'ttl-beg-1)) ; may be a title.
		  (if (zerop (rst-forward-line dir))
		      (if (not
			   (looking-at (rst-re 'ado-beg-2-1))) ; no overline /
							       ; underline.
			  (rst-forward-line (- dir)))))) ; step back to line.
	    (if (not (= (point) pt))
		(point)))))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Indented blocks

(defun rst-forward-indented-block (&optional column limit)
  ;; testcover: ok.
  "Move forward across one indented block.
Find the next (i.e. excluding the current line) non-empty line
which is not indented at least to COLUMN (defaults to the column
of the point).  Move point to first character of this line or the
first of the empty lines immediately before it and return that
position.  If there is no such line before LIMIT (defaults to the
end of the buffer) return nil and do not move point."
  (let (fnd candidate)
    (setq fnd (rst-apply-indented-blocks
  	       (line-beginning-position 2) ; Skip the current line
	       (or limit (point-max)) (or column (current-column))
               (lambda (_count _in-first _in-sub in-super in-empty _relind)
                 (cond
                  (in-empty
                   (setq candidate (or candidate (line-beginning-position)))
                   nil)
                  (in-super
                   (or candidate (line-beginning-position)))
                  (t ; Non-empty, same or more indented line.
                   (setq candidate nil)
                   nil)))))
    (when fnd
      (goto-char fnd))))

(defvar rst-font-lock-find-unindented-line-begin nil
  "Beginning of the match if `rst-font-lock-find-unindented-line-end'.")

(defvar rst-font-lock-find-unindented-line-end nil
  "End of the match as determined by `rst-font-lock-find-unindented-line-limit'.
Also used as a trigger for `rst-font-lock-find-unindented-line-match'.")

(defun rst-font-lock-find-unindented-line-limit (ind-pnt)
  "Find the next unindented line relative to indentation at IND-PNT.
Return this point, the end of the buffer or nil if nothing found.
If IND-PNT is `next' take the indentation from the next line if
this is not empty and indented more than the current one.  If
IND-PNT is non-nil but not a number take the indentation from the
next non-empty line if this is indented more than the current one."
  (setq rst-font-lock-find-unindented-line-begin ind-pnt)
  (setq rst-font-lock-find-unindented-line-end
	(save-match-data
	  (save-excursion
	    (when (not (numberp ind-pnt))
	      ;; Find indentation point in next line if any.
	      (setq ind-pnt
		    ;; FIXME: Should be refactored to two different functions
		    ;;        giving their result to this function, may be
		    ;;        integrated in caller.
		    (save-match-data
		      (let ((cur-ind (current-indentation)))
			(if (eq ind-pnt 'next)
			    (when (and (rst-forward-line-strict 1 (point-max))
				       (< (point) (point-max)))
			      ;; Not at EOF.
			      (setq rst-font-lock-find-unindented-line-begin
				    (point))
			      (when (and (not (looking-at (rst-re 'lin-end)))
					 (> (current-indentation) cur-ind))
			        ;; Use end of indentation if non-empty line.
				(looking-at (rst-re 'hws-tag))
				(match-end 0)))
			  ;; Skip until non-empty line or EOF.
			  (while (and (rst-forward-line-strict 1 (point-max))
				      (< (point) (point-max))
				      (looking-at (rst-re 'lin-end))))
			  (when (< (point) (point-max))
			    ;; Not at EOF.
			    (setq rst-font-lock-find-unindented-line-begin
				  (point))
			    (when (> (current-indentation) cur-ind)
			      ;; Indentation bigger than line of departure.
			      (looking-at (rst-re 'hws-tag))
			      (match-end 0))))))))
	    (when ind-pnt
	      (goto-char ind-pnt)
	      (or (rst-forward-indented-block nil (point-max))
		  (point-max)))))))

(defun rst-font-lock-find-unindented-line-match (_limit)
  "Set the match found earlier if match were found.
Match has been found by `rst-font-lock-find-unindented-line-limit'
the first time called or no match is found.  Return non-nil if
match was found.  _LIMIT is not used but mandated by the caller."
  (when rst-font-lock-find-unindented-line-end
    (set-match-data
     (list rst-font-lock-find-unindented-line-begin
	   rst-font-lock-find-unindented-line-end))
    (put-text-property rst-font-lock-find-unindented-line-begin
		       rst-font-lock-find-unindented-line-end
		       'font-lock-multiline t)
    ;; Make sure this is called only once.
    (setq rst-font-lock-find-unindented-line-end nil)
    t))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Adornments

(defvar rst-font-lock-adornment-level nil
  "Storage for `rst-font-lock-handle-adornment-matcher'.
Either section level of the current adornment or t for a transition.")

(defun rst-adornment-level (ado)
  "Return section level for ADO or t for a transition.
If ADO is found in the hierarchy return its level.  Otherwise
return a level one beyond the existing hierarchy."
  (if (rst-Ado-is-transition ado)
      t
    (let ((hier (rst-Hdr-ado-map (rst-hdr-hierarchy))))
      (1+ (or (rst-Ado-position ado hier)
	      (length hier))))))

(defvar rst-font-lock-adornment-match nil
  "Storage for match for current adornment.
Set by `rst-font-lock-handle-adornment-pre-match-form'.  Also used
as a trigger for `rst-font-lock-handle-adornment-matcher'.")

(defun rst-font-lock-handle-adornment-pre-match-form (ado ado-end)
  "Determine limit for adornments.
Determine all things necessary for font-locking section titles
and transitions and put the result to `rst-font-lock-adornment-match'
and `rst-font-lock-adornment-level'.  ADO is the complete adornment
matched.  ADO-END is the point where ADO ends.  Return the point
where the whole adorned construct ends.

Called as a PRE-MATCH-FORM in the sense of `font-lock-keywords'."
  (let ((ttl (rst-classify-adornment ado ado-end)))
    (if (not ttl)
	(setq rst-font-lock-adornment-level nil
	      rst-font-lock-adornment-match nil)
      (setq rst-font-lock-adornment-level
	    (rst-adornment-level (rst-Ttl-ado ttl)))
      (setq rst-font-lock-adornment-match (rst-Ttl-match ttl))
      (goto-char (rst-Ttl-get-beginning ttl))
      (rst-Ttl-get-end ttl))))

(defun rst-font-lock-handle-adornment-matcher (_limit)
  "Set the match found earlier if match were found.
Match has been found by
`rst-font-lock-handle-adornment-pre-match-form' the first time
called or no match is found.  Return non-nil if match was found.

Called as a MATCHER in the sense of `font-lock-keywords'.
_LIMIT is not used but mandated by the caller."
  (let ((match rst-font-lock-adornment-match))
    ;; May run only once - enforce this.
    (setq rst-font-lock-adornment-match nil)
    (when match
      (set-match-data match)
      (goto-char (match-end 0))
      (put-text-property (match-beginning 0) (match-end 0)
			 'font-lock-multiline t)
      t)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Compilation

(defgroup rst-compile nil
  "Settings for support of conversion of reStructuredText
document with \\[rst-compile]."
  :group 'rst
  :version "21.1")

(defcustom rst-compile-toolsets
  `((html ,(if (executable-find "rst2html.py") "rst2html.py" "rst2html")
          ".html" nil)
    (latex ,(if (executable-find "rst2latex.py") "rst2latex.py" "rst2latex")
           ".tex" nil)
    (newlatex ,(if (executable-find "rst2newlatex.py") "rst2newlatex.py"
                 "rst2newlatex")
              ".tex" nil)
    (pseudoxml ,(if (executable-find "rst2pseudoxml.py") "rst2pseudoxml.py"
                  "rst2pseudoxml")
               ".xml" nil)
    (xml ,(if (executable-find "rst2xml.py") "rst2xml.py" "rst2xml")
         ".xml" nil)
    (pdf ,(if (executable-find "rst2pdf.py") "rst2pdf.py" "rst2pdf")
         ".pdf" nil)
    (s5 ,(if (executable-find "rst2s5.py") "rst2s5.py" "rst2s5")
        ".html" nil))
  ;; FIXME: Add at least those converters officially supported like `rst2odt'
  ;;        and `rst2man'.
  ;; FIXME: To make this really useful there should be a generic command the
  ;;        user gives one of the symbols and this way select the conversion to
  ;;        run. This should replace the toolset stuff somehow.
  ;; FIXME: Allow a template for the conversion command so `rst2pdf ... -o ...'
  ;;        can be supported.
  "Table describing the command to use for each tool-set.
An association list of the tool-set to a list of the (command to use,
extension of produced filename, options to the tool (nil or a
string)) to be used for converting the document."
  ;; FIXME: These are not options but symbols which may be referenced by
  ;;        `rst-compile-*-toolset` below. The `:validate' keyword of
  ;;        `defcustom' may help to define this properly in newer Emacs
  ;;        versions (> 23.1).
  :type '(alist :options (html latex newlatex pseudoxml xml pdf s5)
                :key-type symbol
                :value-type (list :tag "Specification"
                             (file :tag "Command")
                             (string :tag "File extension")
                             (choice :tag "Command options"
                                     (const :tag "No options" nil)
                                     (string :tag "Options"))))
  :group 'rst-compile
  :package-version "1.2.0")

;; FIXME: Must be defcustom.
(defvar rst-compile-primary-toolset 'html
  "The default tool-set for `rst-compile'.")

;; FIXME: Must be defcustom.
(defvar rst-compile-secondary-toolset 'latex
  "The default tool-set for `rst-compile' with a prefix argument.")

(defun rst-compile-find-conf ()
  "Look for the configuration file in the parents of the current path."
  (interactive)
  (let ((file-name "docutils.conf")
        (buffer-file (buffer-file-name)))
    ;; Move up in the dir hierarchy till we find a change log file.
    (let* ((dir (file-name-directory buffer-file))
	   (prevdir nil))
      (while (and (or (not (string= dir prevdir))
		      (setq dir nil)
		      nil)
                  (not (file-exists-p (concat dir file-name))))
        ;; Move up to the parent dir and try again.
	(setq prevdir dir)
        (setq dir (expand-file-name (file-name-directory
                                     (directory-file-name
				      (file-name-directory dir))))))
      (or (and dir (concat dir file-name)) nil))))

(require 'compile)

(defun rst-compile (&optional use-alt)
  "Compile command to convert reST document into some output file.
Attempts to find configuration file, if it can, overrides the
options.  There are two commands to choose from; with USE-ALT,
select the alternative tool-set."
  (interactive "P")
  ;; Note: maybe we want to check if there is a Makefile too and not do anything
  ;; if that is the case.  I dunno.
  (cl-destructuring-bind
      (command extension options
       &aux (conffile (rst-compile-find-conf))
       (bufname (file-name-nondirectory buffer-file-name)))
      (cdr (assq (if use-alt
		     rst-compile-secondary-toolset
		   rst-compile-primary-toolset)
		 rst-compile-toolsets))
    ;; Set compile-command before invocation of compile.
    (setq-local
     compile-command
     (mapconcat
      #'identity
      (list command
	    (or options "")
	    (if conffile
		(concat "--config=" (shell-quote-argument conffile))
	      "")
	    (shell-quote-argument bufname)
	    (shell-quote-argument (concat (file-name-sans-extension bufname)
					  extension)))
      " "))
    ;; Invoke the compile command.
    (if (or compilation-read-command use-alt)
        (call-interactively #'compile)
      (compile compile-command))))

(defun rst-compile-alt-toolset ()
  "Compile command with the alternative tool-set."
  (interactive)
  (rst-compile t))

(defun rst-compile-pseudo-region ()
  "Show pseudo-XML rendering.
Rendering is done of the current active region, or of the entire
buffer, if the region is not selected."
  ;; FIXME: The region should be given interactively.
  (interactive)
  (with-output-to-temp-buffer "*pseudoxml*"
    (shell-command-on-region
     (if mark-active (region-beginning) (point-min))
     (if mark-active (region-end) (point-max))
     (cadr (assq 'pseudoxml rst-compile-toolsets))
     standard-output)))

;; FIXME: Should be integrated in `rst-compile-toolsets'.
(defvar rst-pdf-program "xpdf"
  "Program used to preview PDF files.")

(defun rst-compile-pdf-preview ()
  "Convert the document to a PDF file and launch a preview program."
  (interactive)
  (let* ((tmp-filename (make-temp-file "rst_el" nil ".pdf"))
         (pdf-compile-program (cadr (assq 'pdf rst-compile-toolsets)))
	 (command (format "%s %s %s && %s %s ; rm %s"
			  pdf-compile-program
			  buffer-file-name tmp-filename
			  rst-pdf-program tmp-filename tmp-filename)))
    (unless (executable-find pdf-compile-program)
      (error "Cannot find executable `%s'" pdf-compile-program))
    (unless (executable-find rst-pdf-program)
      (error "Cannot find executable `%s'" rst-pdf-program))
    (start-process-shell-command "rst-pdf-preview" nil command)
    ;; Note: you could also use (compile command) to view the compilation
    ;; output.
    ))

;; FIXME: Should be integrated in `rst-compile-toolsets' defaulting to
;;        something like `browse-url'.
(defvar rst-slides-program "firefox"
  "Program used to preview S5 slides.")

(defun rst-compile-slides-preview ()
  "Convert the document to an S5 slide presentation and launch a preview program."
  (interactive)
  (let* ((tmp-filename (make-temp-file "rst_el" nil ".html"))
	 (command (format "%s %s %s && %s %s ; rm %s"
			  (cadr (assq 's5 rst-compile-toolsets))
			  buffer-file-name tmp-filename
			  rst-slides-program tmp-filename tmp-filename)))
    (start-process-shell-command "rst-slides-preview" nil command)
    ;; Note: you could also use (compile command) to view the compilation
    ;; output.
    ))

;; FIXME: Add `rst-compile-html-preview'.

;; FIXME: Add support for `restview` (https://mg.pov.lt/restview/). May be a
;;        more general facility for calling commands on a reST file would make
;;        sense.


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Imenu support

;; FIXME: Consider a key binding. A key binding needs to definitely switch on
;;        `which-func-mode' - i.e. `which-func-modes' must be set properly.

;; Based on ideas from Masatake YAMATO <yamato@redhat.com>.

(defun rst-imenu-convert-cell (stn)
  "Convert a STN to an Imenu index node and return it."
  (let ((ttl (rst-Stn-ttl stn))
	(children (rst-Stn-children stn))
	(pos (rst-Stn-get-title-beginning stn))
	(txt (rst-Stn-get-text stn ""))
	(pfx " ")
	(sfx "")
	name)
    (when ttl
      (let ((hdr (rst-Ttl-hdr ttl)))
	(setq pfx (char-to-string (rst-Hdr-get-char hdr)))
	(when (rst-Hdr-is-over-and-under hdr)
	  (setq sfx pfx))))
    ;; FIXME: Overline adornment characters need to be in front so they
    ;;        become visible even for long title lines. May be an additional
    ;;        level number is also useful.
    (setq name (format "%s%s%s" pfx txt sfx))
    (cons name ; The name of the entry.
	  (if children
	      (cons ; The entry has a submenu.
	       (cons name pos) ; The entry itself.
	       (mapcar #'rst-imenu-convert-cell children)) ; The children.
	    pos)))) ; The position of a plain entry.

;; FIXME: Document title and subtitle need to be handled properly. They should
;;        get an own "Document" top level entry.
(defun rst-imenu-create-index ()
  "Create index for Imenu.
Return as described for `imenu--index-alist'."
  (rst-reset-section-caches)
  (let ((root (rst-all-stn)))
    (when root
      (mapcar #'rst-imenu-convert-cell (rst-Stn-children root)))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Convenience functions

;; FIXME: Unbound command - should be bound or removed.
(defun rst-replace-lines (fromchar tochar)
  "Replace flush-left lines of FROMCHAR with equal-length lines of TOCHAR."
  (interactive "\
cSearch for flush-left lines of char:
cand replace with char: ")
  (save-excursion
    (let ((searchre (rst-re "^" fromchar "+\\( *\\)$"))
          (found 0))
      (while (search-forward-regexp searchre nil t)
        (setq found (1+ found))
        (goto-char (match-beginning 1))
        (let ((width (current-column)))
          (rst-delete-entire-line 0)
          (insert-char tochar width)))
      (message "%d lines replaced." found))))

;; FIXME: Unbound command - should be bound or removed.
(defun rst-join-paragraph ()
  "Join lines in current paragraph into one line, removing end-of-lines."
  (interactive)
  (let ((fill-column 65000)) ; Some big number.
    (call-interactively #'fill-paragraph)))

;; FIXME: Unbound command - should be bound or removed.
(defun rst-force-fill-paragraph ()
  "Fill paragraph at point, first joining the paragraph's lines into one.
This is useful for filling list item paragraphs."
  (interactive)
  (rst-join-paragraph)
  (fill-paragraph nil))


;; FIXME: Unbound command - should be bound or removed.
;; Generic character repeater function.
;; For sections, better to use the specialized function above, but this can
;; be useful for creating separators.
(defun rst-repeat-last-character (use-next)
  "Fill the current line using the last character on the current line.
Fill up to the length of the preceding line or up to `fill-column' if preceding
line is empty.

If USE-NEXT, use the next line rather than the preceding line.

If the current line is longer than the desired length, shave the characters off
the current line to fit the desired length.

As an added convenience, if the command is repeated immediately, the alternative
column is used (fill-column vs. end of previous/next line)."
  (interactive "P")
  (let* ((curcol (current-column))
         (curline (+ (count-lines (point-min) (point))
                     (if (zerop curcol) 1 0)))
         (lbp (line-beginning-position 0))
         (prevcol (if (and (= curline 1) (not use-next))
                      fill-column
                    (save-excursion
                      (forward-line (if use-next 1 -1))
                      (end-of-line)
                      (skip-chars-backward " \t" lbp)
                      (let ((cc (current-column)))
                        (if (zerop cc) fill-column cc)))))
         (rightmost-column
          (cond ((equal last-command 'rst-repeat-last-character)
                 (if (= curcol fill-column) prevcol fill-column))
                (t (save-excursion
                     (if (zerop prevcol) fill-column prevcol))))))
    (end-of-line)
    (if (> (current-column) rightmost-column)
        ;; Shave characters off the end.
        (delete-region (- (point)
                          (- (current-column) rightmost-column))
                       (point))
      ;; Fill with last characters.
      (insert-char (preceding-char)
                   (- rightmost-column (current-column))))))



;; LocalWords:  docutils http sourceforge rst html wp svn svnroot txt reST regex
;; LocalWords:  regexes alist seq alt grp keymap abbrev overline overlines toc
;; LocalWords:  XML PNT propertized init referenceable

(provide 'rst)

;; Local Variables:
;; sentence-end-double-space: t
;; End:

;;; rst.el ends here
