Docstrings from 'org-element.el'

(eval-when-compile (require 'cl))
(require 'org)

(defconst org-element-paragraph-separate
  (concat "^\\(?:"
          ;; Headlines, inlinetasks.
          org-outline-regexp "\\|"
          ;; Footnote definitions.
          "\\[\\(?:[0-9]+\\|fn:[-_[:word:]]+\\)\\]" "\\|"
          ;; Diary sexps.
          "%%(" "\\|"
          "[ \t]*\\(?:"
          ;; Empty lines.
          "$" "\\|"
          ;; Tables (any type).
          "\\(?:|\\|\\+-[-+]\\)" "\\|"
          ;; Blocks (any type), Babel calls, drawers (any type),
          ;; fixed-width areas and keywords.  Note: this is only an
          ;; indication and need some thorough check.
          "[#:]" "\\|"
          ;; Horizontal rules.
          "-\\{5,\\}[ \t]*$" "\\|"
          ;; LaTeX environments.
          "\\\\begin{\\([A-Za-z0-9]+\\*?\\)}" "\\|"
          ;; Planning and Clock lines.
          (regexp-opt (list org-scheduled-string
                            org-deadline-string
                            org-closed-string
                            org-clock-string))
          "\\|"
          ;; Lists.
          (let ((term (case org-plain-list-ordered-item-terminator
                        (?\) ")") (?. "\\.") (otherwise "[.)]")))
                (alpha (and org-list-allow-alphabetical "\\|[A-Za-z]")))
            (concat "\\(?:[-+*]\\|\\(?:[0-9]+" alpha "\\)" term "\\)"
                    "\\(?:[ \t]\\|$\\)"))
          "\\)\\)")
  "Regexp to separate paragraphs in an Org buffer.
In the case of lines starting with \"#\" and \":\", this regexp
is not sufficient to know if point is at a paragraph ending.  See
`org-element-paragraph-parser' for more information.")

(defconst org-element-all-elements
  '(babel-call center-block clock comment comment-block diary-sexp drawer
               dynamic-block example-block export-block fixed-width
               footnote-definition headline horizontal-rule inlinetask item
               keyword latex-environment node-property paragraph plain-list
               planning property-drawer quote-block quote-section section
               special-block src-block table table-row verse-block)
  "Complete list of element types.")

(defconst org-element-greater-elements
  '(center-block drawer dynamic-block footnote-definition headline inlinetask
                 item plain-list property-drawer quote-block section
                 special-block table)
  "List of recursive element types aka Greater Elements.")

(defconst org-element-all-successors
  '(export-snippet footnote-reference inline-babel-call inline-src-block
                   latex-or-entity line-break link macro plain-link radio-target
                   statistics-cookie sub/superscript table-cell target
                   text-markup timestamp)
  "Complete list of successors.")

(defconst org-element-object-successor-alist
  '((subscript . sub/superscript) (superscript . sub/superscript)
    (bold . text-markup) (code . text-markup) (italic . text-markup)
    (strike-through . text-markup) (underline . text-markup)
    (verbatim . text-markup) (entity . latex-or-entity)
    (latex-fragment . latex-or-entity))
  "Alist of translations between object type and successor name.
Sharing the same successor comes handy when, for example, the
regexp matching one object can also match the other object.")

(defconst org-element-all-objects
  '(bold code entity export-snippet footnote-reference inline-babel-call
         inline-src-block italic line-break latex-fragment link macro
         radio-target statistics-cookie strike-through subscript superscript
         table-cell target timestamp underline verbatim)
  "Complete list of object types.")

(defconst org-element-recursive-objects
  '(bold italic link subscript radio-target strike-through superscript
         table-cell underline)
  "List of recursive object types.")

(defvar org-element-block-name-alist
  '(("CENTER" . org-element-center-block-parser)
    ("COMMENT" . org-element-comment-block-parser)
    ("EXAMPLE" . org-element-example-block-parser)
    ("QUOTE" . org-element-quote-block-parser)
    ("SRC" . org-element-src-block-parser)
    ("VERSE" . org-element-verse-block-parser))
  "Alist between block names and the associated parsing function.
Names must be uppercase.  Any block whose name has no association
is parsed with `org-element-special-block-parser'.")

(defconst org-element-link-type-is-file
  '("file" "file+emacs" "file+sys" "docview")
  "List of link types equivalent to \"file\".
Only these types can accept search options and an explicit
application to open them.")

(defconst org-element-affiliated-keywords
  '("CAPTION" "DATA" "HEADER" "HEADERS" "LABEL" "NAME" "PLOT" "RESNAME" "RESULT"
    "RESULTS" "SOURCE" "SRCNAME" "TBLNAME")
  "List of affiliated keywords as strings.
By default, all keywords setting attributes (i.e. \"ATTR_LATEX\")
are affiliated keywords and need not to be in this list.")

(defconst org-element--affiliated-re
  (format "[ \t]*#\\+%s:"
          ;; Regular affiliated keywords.
          (format "\\(%s\\|ATTR_[-_A-Za-z0-9]+\\)\\(?:\\[\\(.*\\)\\]\\)?"
                  (regexp-opt org-element-affiliated-keywords)))
  "Regexp matching any affiliated keyword.

Keyword name is put in match group 1.  Moreover, if keyword
belongs to `org-element-dual-keywords', put the dual value in
match group 2.

Don't modify it, set `org-element-affiliated-keywords' instead.")

(defconst org-element-keyword-translation-alist
  '(("DATA" . "NAME")  ("LABEL" . "NAME") ("RESNAME" . "NAME")
    ("SOURCE" . "NAME") ("SRCNAME" . "NAME") ("TBLNAME" . "NAME")
    ("RESULT" . "RESULTS") ("HEADERS" . "HEADER"))
  "Alist of usual translations for keywords.
The key is the old name and the value the new one.  The property
holding their value will be named after the translated name.")

(defconst org-element-multiple-keywords '("CAPTION" "HEADER")
  "List of affiliated keywords that can occur more than once in an element.

Their value will be consed into a list of strings, which will be
returned as the value of the property.

This list is checked after translations have been applied.  See
`org-element-keyword-translation-alist'.

By default, all keywords setting attributes (i.e. \"ATTR_LATEX\")
allow multiple occurrences and need not to be in this list.")

(defconst org-element-parsed-keywords '("CAPTION")
  "List of affiliated keywords whose value can be parsed.

Their value will be stored as a secondary string: a list of
strings and objects.

This list is checked after translations have been applied.  See
`org-element-keyword-translation-alist'.")

(defconst org-element-dual-keywords '("CAPTION" "RESULTS")
  "List of affiliated keywords which can have a secondary value.

In Org syntax, they can be written with optional square brackets
before the colons.  For example, RESULTS keyword can be
associated to a hash value with the following:

  #+RESULTS[hash-string]: some-source

This list is checked after translations have been applied.  See
`org-element-keyword-translation-alist'.")

(defconst org-element-document-properties '("AUTHOR" "DATE" "TITLE")
  "List of properties associated to the whole document.
Any keyword in this list will have its value parsed and stored as
a secondary string.")

(defconst org-element-object-restrictions
  (let* ((standard-set
          (remq 'plain-link (remq 'table-cell org-element-all-successors)))
         (standard-set-no-line-break (remq 'line-break standard-set)))
    `((bold ,@standard-set)
      (footnote-reference ,@standard-set)
      (headline ,@standard-set-no-line-break)
      (inlinetask ,@standard-set-no-line-break)
      (italic ,@standard-set)
      (item ,@standard-set-no-line-break)
      (keyword ,@standard-set)
      ;; Ignore all links excepted plain links in a link description.
      ;; Also ignore radio-targets and line breaks.
      (link export-snippet inline-babel-call inline-src-block latex-or-entity
            macro plain-link statistics-cookie sub/superscript text-markup)
      (paragraph ,@standard-set)
      ;; Remove any variable object from radio target as it would
      ;; prevent it from being properly recognized.
      (radio-target latex-or-entity sub/superscript)
      (strike-through ,@standard-set)
      (subscript ,@standard-set)
      (superscript ,@standard-set)
      ;; Ignore inline babel call and inline src block as formulas are
      ;; possible.  Also ignore line breaks and statistics cookies.
      (table-cell export-snippet footnote-reference latex-or-entity link macro
                  radio-target sub/superscript target text-markup timestamp)
      (table-row table-cell)
      (underline ,@standard-set)
      (verse-block ,@standard-set)))
  "Alist of objects restrictions.

CAR is an element or object type containing objects and CDR is
a list of successors that will be called within an element or
object of such type.

For example, in a `radio-target' object, one can only find
entities, latex-fragments, subscript and superscript.

This alist also applies to secondary string.  For example, an
`headline' type element doesn't directly contain objects, but
still has an entry since one of its properties (`:title') does.")

(defconst org-element-secondary-value-alist
  '((headline . :title)
    (inlinetask . :title)
    (item . :tag)
    (footnote-reference . :inline-definition))
  "Alist between element types and location of secondary value.")

(defconst org-element-object-variables '(org-link-abbrev-alist-local)
  "List of buffer-local variables used when parsing objects.
These variables are copied to the temporary buffer created by
`org-export-secondary-string'.")

(defsubst org-element-type (element)
  "Return type of ELEMENT.

The function returns the type of the element or object provided.
It can also return the following special value:
  `plain-text'       for a string
  `org-data'         for a complete document
  nil                in any other case.")

(defsubst org-element-property (property element)
  "Extract the value from the PROPERTY of an ELEMENT.")

(defsubst org-element-contents (element)
  "Extract contents from an ELEMENT.")

(defsubst org-element-restriction (element)
  "Return restriction associated to ELEMENT.
ELEMENT can be an element, an object or a symbol representing an
element or object type.")

(defsubst org-element-put-property (element property value)
  "In ELEMENT set PROPERTY to VALUE.
Return modified element.")

(defsubst org-element-set-contents (element &rest contents)
  "Set ELEMENT contents to CONTENTS.
Return modified element.")

(defsubst org-element-set-element (old new)
  "Replace element or object OLD with element or object NEW.
The function takes care of setting `:parent' property for NEW.")

(defsubst org-element-adopt-elements (parent &rest children)
  "Append elements to the contents of another element.

PARENT is an element or object.  CHILDREN can be elements,
objects, or a strings.

The function takes care of setting `:parent' property for CHILD.
Return parent element.")

(defun org-element--current-element
  (limit &optional granularity special structure)
  "Parse the element starting at point.

LIMIT bounds the search.

Return value is a list like (TYPE PROPS) where TYPE is the type
of the element and PROPS a plist of properties associated to the
element.

Possible types are defined in `org-element-all-elements'.

Optional argument GRANULARITY determines the depth of the
recursion.  Allowed values are `headline', `greater-element',
`element', `object' or nil.  When it is broader than `object' (or
nil), secondary values will not be parsed, since they only
contain objects.

Optional argument SPECIAL, when non-nil, can be either
`first-section', `item', `node-property', `quote-section',
`section', and `table-row'.

If STRUCTURE isn't provided but SPECIAL is set to `item', it will
be computed.

This function assumes point is always at the beginning of the
element it has to parse.")

(defun org-element--collect-affiliated-keywords (limit)
  "Collect affiliated keywords from point down to LIMIT.

Return a list whose CAR is the position at the first of them and
CDR a plist of keywords and values and move point to the
beginning of the first line after them.

As a special case, if element doesn't start at the beginning of
the line (i.e. a paragraph starting an item), CAR is current
position of point and CDR is nil.")

(defun org-element-parse-buffer (&optional granularity visible-only)
  "Recursively parse the buffer and return structure.
If narrowing is in effect, only parse the visible part of the
buffer.

Optional argument GRANULARITY determines the depth of the
recursion.  It can be set to the following symbols:

`headline'          Only parse headlines.
`greater-element'   Don't recurse into greater elements excepted
                    headlines and sections.  Thus, elements
                    parsed are the top-level ones.
`element'           Parse everything but objects and plain text.
`object'            Parse the complete buffer (default).

When VISIBLE-ONLY is non-nil, don't parse contents of hidden
elements.

An element or an objects is represented as a list with the
pattern (TYPE PROPERTIES CONTENTS), where :

  TYPE is a symbol describing the element or object.  See
  `org-element-all-elements' and `org-element-all-objects' for an
  exhaustive list of such symbols.  One can retrieve it with
  `org-element-type' function.

  PROPERTIES is the list of attributes attached to the element or
  object, as a plist.  Although most of them are specific to the
  element or object type, all types share `:begin', `:end',
  `:post-blank' and `:parent' properties, which respectively
  refer to buffer position where the element or object starts,
  ends, the number of white spaces or blank lines after it, and
  the element or object containing it.  Properties values can be
  obtained by using `org-element-property' function.

  CONTENTS is a list of elements, objects or raw strings
  contained in the current element or object, when applicable.
  One can access them with `org-element-contents' function.

The Org buffer has `org-data' as type and nil as properties.
`org-element-map' function can be used to find specific elements
or objects within the parse tree.

This function assumes that current major mode is `org-mode'.")

(defun org-element-parse-secondary-string (string restriction &optional parent)
  "Recursively parse objects in STRING and return structure.

RESTRICTION is a symbol limiting the object types that will be
looked after.

Optional argument PARENT, when non-nil, is the element or object
containing the secondary string.  It is used to set correctly
`:parent' property within the string."
  ;; Copy buffer-local variables listed in
  ;; `org-element-object-variables' into temporary buffer.  This is
  ;; required since object parsing is dependent on these variables.)

(defun org-element-map
  (data types fun &optional info first-match no-recursion with-affiliated)
  "Map a function on selected elements or objects.

DATA is a parse tree, an element, an object, a string, or a list
of such constructs.  TYPES is a symbol or list of symbols of
elements or objects types (see `org-element-all-elements' and
`org-element-all-objects' for a complete list of types).  FUN is
the function called on the matching element or object.  It has to
accept one argument: the element or object itself.

When optional argument INFO is non-nil, it should be a plist
holding export options.  In that case, parts of the parse tree
not exportable according to that property list will be skipped.

When optional argument FIRST-MATCH is non-nil, stop at the first
match for which FUN doesn't return nil, and return that value.

Optional argument NO-RECURSION is a symbol or a list of symbols
representing elements or objects types.  `org-element-map' won't
enter any recursive element or object whose type belongs to that
list.  Though, FUN can still be applied on them.

When optional argument WITH-AFFILIATED is non-nil, FUN will also
apply to matching objects within parsed affiliated keywords (see
`org-element-parsed-keywords').

Nil values returned from FUN do not appear in the results.


Examples:
---------

Assuming TREE is a variable containing an Org buffer parse tree,
the following example will return a flat list of all `src-block'
and `example-block' elements in it:

  \(org-element-map tree '(example-block src-block) 'identity)

The following snippet will find the first headline with a level
of 1 and a \"phone\" tag, and will return its beginning position:

  \(org-element-map tree 'headline
   \(lambda (hl)
     \(and (= (org-element-property :level hl) 1)
          \(member \"phone\" (org-element-property :tags hl))
          \(org-element-property :begin hl)))
   nil t)

The next example will return a flat list of all `plain-list' type
elements in TREE that are not a sub-list themselves:

  \(org-element-map tree 'plain-list 'identity nil nil 'plain-list)

Eventually, this example will return a flat list of all `bold'
type objects containing a `latex-snippet' type object, even
looking into captions:

  \(org-element-map tree 'bold
   \(lambda (b)
     \(and (org-element-map b 'latex-snippet 'identity nil t) b))
   nil nil nil t)"
  ;; Ensure TYPES and NO-RECURSION are a list, even of one element.
  (unless (listp types) (setq types (list types)))
  (unless (listp no-recursion) (setq no-recursion (list no-recursion)))
  ;; Recursion depth is determined by --CATEGORY.
  (let* ((--category
          (catch 'found
            (let ((category 'greater-elements))
              (mapc (lambda (type)
                      (cond ((or (memq type org-element-all-objects)
                                 (eq type 'plain-text))
                             ;; If one object is found, the function
                             ;; has to recurse into every object.
                             (throw 'found 'objects))
                            ((not (memq type org-element-greater-elements))
                             ;; If one regular element is found, the
                             ;; function has to recurse, at least,
                             ;; into every element it encounters.
                             (and (not (eq category 'elements))
                                  (setq category 'elements)))))
                    types)
              category)))
         ;; Compute properties for affiliated keywords if necessary.
         (--affiliated-alist
          (and with-affiliated
               (mapcar (lambda (kwd)
                         (cons kwd (intern (concat ":" (downcase kwd)))))
                       org-element-affiliated-keywords)))
         --acc
         --walk-tree
         (--walk-tree
          (function
           (lambda (--data)
             ;; Recursively walk DATA.  INFO, if non-nil, is a plist
             ;; holding contextual information.
             (let ((--type (org-element-type --data)))
               (cond
                ((not --data))
                ;; Ignored element in an export context.
                ((and info (memq --data (plist-get info :ignore-list))))
                ;; List of elements or objects.
                ((not --type) (mapc --walk-tree --data))
                ;; Unconditionally enter parse trees.
                ((eq --type 'org-data)
                 (mapc --walk-tree (org-element-contents --data)))
                (t
                 ;; Check if TYPE is matching among TYPES.  If so,
                 ;; apply FUN to --DATA and accumulate return value
                 ;; into --ACC (or exit if FIRST-MATCH is non-nil).
                 (when (memq --type types)
                   (let ((result (funcall fun --data)))
                     (cond ((not result))
                           (first-match (throw '--map-first-match result))
                           (t (push result --acc)))))
                 ;; If --DATA has a secondary string that can contain
                 ;; objects with their type among TYPES, look into it.
                 (when (and (eq --category 'objects) (not (stringp --data)))
                   (let ((sec-prop
                          (assq --type org-element-secondary-value-alist)))
                     (when sec-prop
                       (funcall --walk-tree
                                (org-element-property (cdr sec-prop) --data)))))
                 ;; If --DATA has any affiliated keywords and
                 ;; WITH-AFFILIATED is non-nil, look for objects in
                 ;; them.
                 (when (and with-affiliated
                            (eq --category 'objects)
                            (memq --type org-element-all-elements))
                   (mapc (lambda (kwd-pair)
                           (let ((kwd (car kwd-pair))
                                 (value (org-element-property
                                         (cdr kwd-pair) --data)))
                             ;; Pay attention to the type of value.
                             ;; Preserve order for multiple keywords.
                             (cond
                              ((not value))
                              ((and (member kwd org-element-multiple-keywords)
                                    (member kwd org-element-dual-keywords))
                               (mapc (lambda (line)
                                       (funcall --walk-tree (cdr line))
                                       (funcall --walk-tree (car line)))
                                     (reverse value)))
                              ((member kwd org-element-multiple-keywords)
                               (mapc (lambda (line) (funcall --walk-tree line))
                                     (reverse value)))
                              ((member kwd org-element-dual-keywords)
                               (funcall --walk-tree (cdr value))
                               (funcall --walk-tree (car value)))
                              (t (funcall --walk-tree value)))))
                         --affiliated-alist))
                 ;; Determine if a recursion into --DATA is possible.
                 (cond
                  ;; --TYPE is explicitly removed from recursion.
                  ((memq --type no-recursion))
                  ;; --DATA has no contents.
                  ((not (org-element-contents --data)))
                  ;; Looking for greater elements but --DATA is simply
                  ;; an element or an object.
                  ((and (eq --category 'greater-elements)
                        (not (memq --type org-element-greater-elements))))
                  ;; Looking for elements but --DATA is an object.
                  ((and (eq --category 'elements)
                        (memq --type org-element-all-objects)))
                  ;; In any other case, map contents.
                  (t (mapc --walk-tree (org-element-contents --data)))))))))))
    (catch '--map-first-match
      (funcall --walk-tree data)
      ;; Return value in a proper order.
      (nreverse --acc))))
(put 'org-element-map 'lisp-indent-function 2)

(defun org-element--parse-elements
  (beg end special structure granularity visible-only acc)
  "Parse elements between BEG and END positions.

SPECIAL prioritize some elements over the others.  It can be set
to `first-section', `quote-section', `section' `item' or
`table-row'.

When value is `item', STRUCTURE will be used as the current list
structure.

GRANULARITY determines the depth of the recursion.  See
`org-element-parse-buffer' for more information.

When VISIBLE-ONLY is non-nil, don't parse contents of hidden
elements.

Elements are accumulated into ACC.")

(defun org-element--parse-objects (beg end acc restriction)
  "Parse objects between BEG and END and return recursive structure.

Objects are accumulated in ACC.

RESTRICTION is a list of object successors which are allowed in
the current object.")

(defun org-element--get-next-object-candidates (limit restriction objects)
  "Return an alist of candidates for the next object.

LIMIT bounds the search, and RESTRICTION narrows candidates to
some object successors.

OBJECTS is the previous candidates alist.  If it is set to
`initial', no search has been done before, and all symbols in
RESTRICTION should be looked after.

Return value is an alist whose CAR is the object type and CDR its
beginning position.")

(defun org-element-interpret-data (data &optional parent)
  "Interpret DATA as Org syntax.

DATA is a parse tree, an element, an object or a secondary string
to interpret.

Optional argument PARENT is used for recursive calls.  It contains
the element or object containing data, or nil.

Return Org syntax as a string.")

(defun org-element--interpret-affiliated-keywords (element)
  "Return ELEMENT's affiliated keywords as Org syntax.
If there is no affiliated keyword, return the empty string.")

(defun org-element-normalize-string (s)
  "Ensure string S ends with a single newline character.

If S isn't a string return it unchanged.  If S is the empty
string, return it.  Otherwise, return a new string with a single
newline character at its end.")

(defun org-element-normalize-contents (element &optional ignore-first)
  "Normalize plain text in ELEMENT's contents.

ELEMENT must only contain plain text and objects.

If optional argument IGNORE-FIRST is non-nil, ignore first line's
indentation to compute maximal common indentation.

Return the normalized element that is element with global
indentation removed from its contents.  The function assumes that
indentation is not done with TAB characters.")

(defun org-element-at-point (&optional keep-trail)
  "Determine closest element around point.

Return value is a list like (TYPE PROPS) where TYPE is the type
of the element and PROPS a plist of properties associated to the
element.

Possible types are defined in `org-element-all-elements'.
Properties depend on element or object type, but always include
`:begin', `:end', `:parent' and `:post-blank' properties.

As a special case, if point is at the very beginning of a list or
sub-list, returned element will be that list instead of the first
item.  In the same way, if point is at the beginning of the first
row of a table, returned element will be the table instead of the
first row.

If optional argument KEEP-TRAIL is non-nil, the function returns
a list of elements leading to element at point.  The list's CAR
is always the element at point.  The following positions contain
element's siblings, then parents, siblings of parents, until the
first element of current section.")

(defun org-element-context (&optional element)
  "Return closest element or object around point.

Return value is a list like (TYPE PROPS) where TYPE is the type
of the element or object and PROPS a plist of properties
associated to it.

Possible types are defined in `org-element-all-elements' and
`org-element-all-objects'.  Properties depend on element or
object type, but always include `:begin', `:end', `:parent' and
`:post-blank'.

Optional argument ELEMENT, when non-nil, is the closest element
containing point, as returned by `org-element-at-point'.
Providing it allows for quicker computation.")

(defun org-element-nested-p (elem-A elem-B)
  "Non-nil when elements ELEM-A and ELEM-B are nested.")

(defun org-element-swap-A-B (elem-A elem-B)
  "Swap elements ELEM-A and ELEM-B.
Assume ELEM-B is after ELEM-A in the buffer.  Leave point at the
end of ELEM-A.")

(provide 'org-element)