NAME
    Pandoc::Elements - create and process Pandoc documents
SYNOPSIS
    The output of this script hello.pl
        use Pandoc::Elements;
        use JSON;
    
        print Document({
                title => MetaInlines [ Str "Greeting" ]
            }, [
                Header( 1, attributes { id => 'top' }, [ Str 'Hello' ] ),
                Para [ Str 'Hello, world!' ],
            ])->to_json;
    can be converted for instance to HTML with via
        ./hello.pl | pandoc -f json -t html5 --standalone
    an equivalent Pandoc Markdown document would be
        % Greeting
        # Gruß {.de}
        Hello, world!
DESCRIPTION
    Pandoc::Elements provides utility functions to create abstract syntax
    trees (AST) of Pandoc  documents. Pandoc can
    convert the resulting data structure to many other document formats,
    such as HTML, LaTeX, ODT, and ePUB.
    Please make sure to use at least Pandoc 1.12 when processing documents
    See also module Pandoc::Filter, command line scripts pandocwalk and
    pod2pandoc, and the internal modules Pandoc::Walker,
    Pandoc::Filter::Lazy, and Pod::Simple::Pandoc.
 EXPORTED FUNCTIONS
    The following functions and keywords are exported by default:
      * Constructors for all Pandoc document element (block elements such
      as Para and inline elements such as Emph, metadata elements and the
      "Document" in DOCUMENT ELEMENT).
      * Type keywords such as Decimal and LowerAlpha to be used as types in
      other document elements.
      * The helper following functions pandoc_json, attributes, citation,
      and element.
  pandoc_json $json
    Parse a JSON string, as emitted by pandoc in JSON format. This is the
    reverse to method to_json but it can read both old (before Pandoc 1.16)
    and new format.
  attributes { key => $value, ... }
    Maps a hash reference or instance of Hash::MultiValue into an
    attributes list with id, classes, and ordered key-value pairs. The
    special keys id (string), and class (string or array reference with
    space-separated class names) are recognized. You can always manually
    create an attributes structure:
        [ $id, [ @classes ], [ [ key => $value ], ... ] ]
    Elements with attributes (element accessor method attr) also provide
    the accessor method id, classes, class, and keyvals. The keyvals
    accessor returns an instance of Hash::MultiValue (but key-value pairs
    cannot be modified through this interface). All attribute accessors can
    also be used as setters.
  citation { ... }
    A citation as part of document element Cite must be a hash reference
    with fields citationID (string), citationPrefix (list of inline
    elements) citationSuffix (list of inline elements), citationMode (one
    of NormalCitation, AuthorInText, SuppressAuthor), citationNoteNum
    (integer), and citationHash (integer). The helper method citation can
    be used to construct such hash by filling in default values and using
    shorter field names (id, prefix, suffix, mode, note, and hash):
        citation {
            id => 'foo',
            prefix => [ Str "see" ],
            suffix => [ Str "p.", Space, Str "42" ]
        }
    
        # in Pandoc Markdown
    
        [see @foo p. 42]
  element( $name => $content )
    Create a Pandoc document element of arbitrary name. This function is
    only exported on request.
ELEMENTS
    Document elements are encoded as Perl data structures equivalent to the
    JSON structure, emitted with pandoc output format json. All elements
    are blessed objects that provide the following element methods and
    additional accessor methods specific to each element.
 ELEMENT METHODS
  to_json
    Return the element as JSON encoded string. The following are
    equivalent:
        $element->to_json;
        JSON->new->utf8->convert_blessed->encode($element);
    Note that the JSON format changed from Pandoc 1.15 to Pandoc 1.16 by
    introduction of attributes to Link and Image elements. Since
    Pandoc::Elements 0.16 the new format is serialized by default. Set the
    package variable or environment variable PANDOC_VERSION to 1.15 or
    below to use the old format.
  name
    Return the name of the element, e.g. "Para" for a paragraph element.
  content
    Return the element content. For most elements (Para, Emph, Str...) the
    content is an array reference with child elements. Other elements
    consist of multiple parts; for instance the Link element has attributes
    (attr, id, class, classes, keyvals) a link text (content) and a link
    target (target) with url and title.
  is_block
    True if the element is a Block element
  is_inline
    True if the element is an inline Inline element
  is_meta
    True if the element is a Metadata element
  is_document
    True if the element is a Document element
  walk(...)
    Walk the element tree with Pandoc::Walker
  query(...)
    Query the element to extract results with Pandoc::Walker
  transform(...)
    Transform the element tree with Pandoc::Walker
  string
    Returns a concatenated string of element content, leaving out all
    formatting.
 BLOCK ELEMENTS
  BlockQuote
    Block quote, consisting of a list of blocks (content)
        BlockQuote [ @blocks ]
  BulletList
    Unnumbered list of items (content=items), each a list of blocks
        BulletList [ [ @blocks ] ]
  CodeBlock
    Code block (literal string content) with attributes (attr, id, class,
    classes, keyvals)
        CodeBlock $attributes, $content
  DefinitionList
    Definition list, consisting of a list of pairs (content=items), each a
    term (term, a list of inlines) and one or more definitions
    (definitions, a list of blocks).
        DefinitionList [ @definitions ]
    
        # each item in @definitions being a pair of the form
    
            [ [ @inlines ], [ @blocks ] ]
  Div
    Generic container of blocks (content) with attributes (attr, id, class,
    classes, keyvals).
        Div $attributes, [ @blocks ]
  Header
    Header with level (integer), attributes (attr, id, class, classes,
    keyvals), and text (content, a list of inlines).
        Header $level, $attributes, [ @inlines ]
  HorizontalRule
    Horizontal rule
        HorizontalRule
  Null
    Nothing
        Null
  OrderedList
    Numbered list of items (content=items), each a list of blocks),
    preceded by list attributes (start number, numbering style, and
    delimiter).
        OrderedList [ $start, $style, $delim ], [ [ @blocks ] ]
    Supported styles are DefaultStyle, Example, Decimal, LowerRoman,
    UpperRoman, LowerAlpha, and UpperAlpha.
    Supported delimiters are DefaultDelim, Period, OneParen, and TwoParens.
  Para
    Paragraph, consisting of a list of Inline elements (content).
        Para [ $elements ]
  Plain
    Plain text, not a paragraph, consisting of a list of Inline elements
    (content).
        Plain [ @inlines ]
  RawBlock
    Raw block with format and content string.
        RawBlock $format, $content
  Table
    Table, with caption, column alignments, relative column widths (0 =
    default), column headers (each a list of blocks), and rows (each a list
    of lists of blocks).
        Table [ @inlines ], [ @alignments ], [ @width ], [ @headers ], [ @rows ]
    Possible alignments are AlignLeft, AlignRight, AlignCenter, and
    AlignDefault.
    An example:
        Table [Str "Example"], [AlignLeft,AlignRight], [0.0,0.0],
         [[Plain [Str "name"]]
         ,[Plain [Str "number"]]],
         [[[Plain [Str "Alice"]]
          ,[Plain [Str "42"]]]
         ,[[Plain [Str "Bob"]]
          ,[Plain [Str "23"]]]];
 INLINE ELEMENTS
  Cite
    Citation, a list of citations and a list of inlines (content). See
    helper function "citation" in citation to construct citations.
        Cite [ @citations ], [ @inlines ]
  Code
    Inline code, a literal string (content) with attributes (attr, id,
    class, classes, keyvals)
        Code attributes { %attr }, $content
  Emph
    Emphasized text, a list of inlines (content).
        Emph [ @inlines ]
  Image
    Image with alt text (content, a list of inlines) and target (list of
    url and title) with attributes (attr, id, class, classes, keyvals).
        Image attributes { %attr }, [ @inlines ], [ $url, $title ]
    Serializing the attributes in JSON can be disabled with PANDOC_VERSION.
  LineBreak
    Hard line break
        LineBreak
  Link
    Hyperlink with link text (content, a list of inlines) and target (list
    of url and title) with attributes (attr, id, class, classes, keyvals).
        Link attributes { %attr }, [ @inlines ], [ $url, $title ]
    Serializing the attributes in JSON can be disabled with PANDOC_VERSION.
  Math
    TeX math, given as literal string (content) with type (one of
    DisplayMath and InlineMath).
        Math $type, $content
  Note
    Footnote or Endnote, a list of blocks (content).
        Note [ @blocks ]
  Quoted
    Quoted text with quote type (one of SingleQuote and DoubleQuote) and a
    list of inlines (content).
        Quoted $type, [ @inlines ]
  RawInline
    Raw inline with format (a string) and content (a string).
        RawInline $format, $content
  SmallCaps
    Small caps text, a list of inlines (content).
        SmallCaps [ @inlines ]
  SoftBreak
    Soft line break
        SoftBreak
    Note that the SoftBreak element was added in Pandoc 1.16 to as a matter
    of editing convenience to preserve line breaks (as opposed to paragraph
    breaks) from input source to output. If you are going to feed a
    document containing SoftBreak elements to Pandoc < 1.16 you will have
    to set the package variable or environment variable PANDOC_VERSION to
    1.15 or below.
  Space
    Inter-word space
        Space
  Span
    Generic container of inlines (content) with attributes (attr, id,
    class, classes, keyvals).
        Span attributes { %attr }, [ @inlines ]
  Str
    Plain text, a string (content).
        Str $text
  Strikeout
    Strikeout text, a list of inlines (content).
        Strikeout [ @inlines ]
  Strong
    Strongly emphasized text, a list of inlines (content).
        Strong [ @inlines ]
  Subscript
    Subscripted text, a list of inlines (content).
        Supscript [ @inlines ]
  Superscript
    Superscripted text, a list of inlines (content).
        Superscript [ @inlines ]
 METADATA ELEMENTS
  MetaBlocks
  MetaBool
  MetaInlines
  MetaList
  MetaMap
  MetaString
 DOCUMENT ELEMENT
  Document
    Root element, consisting of metadata hash (meta) and document element
    array (content).
        Document $meta, [ @blocks ]
 TYPE KEYWORDS
    The following document elements are only as used as type keywords in
    other document elements:
      * SingleQuote, DoubleQuote
      * DisplayMath, InlineMath
      * AuthorInText, SuppressAuthor, NormalCitation
      * AlignLeft, AlignRight, AlignCenter, AlignDefault
      * DefaultStyle, Example, Decimal, LowerRoman, UpperRoman, LowerAlpha,
      UpperAlpha
      * DefaultDelim, Period, OneParen, TwoParens
SEE ALSO
    Pandoc implements a wrapper around the pandoc executable.
    Text.Pandoc.Definition
     contains the original definition of Pandoc document data
    structure in Haskell. This module version was last aligned with
    pandoc-types-1.16.1.
AUTHOR
    Jakob Voß 
CONTRIBUTORS
    Benct Philip Jonsson 
COPYRIGHT AND LICENSE
    Copyright 2014- Jakob Voß
    GNU General Public License, Version 2
    This module is heavily based on Pandoc by John MacFarlane.