Reasons: - Performance: HsYAML is around 20 times slower in parsing large YAML bibliographies (#6084). - An issue was submitted to HsYAML, but it hasn't gotten any attention. HsYAML seems borderline unmaintained; it hasn't had a commit in over a year. - Unfortunately this goes back on our attempts to free ourselves from C dependencies (#4535). But I don't see a better alternative until a better pure Haskell parser is available. Closes #6084. Notes: - We've removed the FromYAML instances for all types that had them, since this is a HsYAML-specific typeclass [API change]. (The yaml package just uses From/ToJSON.) - Unlike HsYAML (in the configuration we were using), yaml parses 'Y', 'N', 'Yes', 'No', 'On', 'Off' as boolean values. Users may need to quote these when they are meant to be interpreted as strings. Similarly, 'null' is parsed as a YAML null value (and will be treated as an empty string by pandoc rather than the string 'null'). Quoting it will force it to be interpreted as a string. - Some tests had to be adjusted accordingly. - Pandoc now behaves better when the YAML metadata contains escaping errors: instead of just falling back on treating the section as a table, it raises a YAML parsing error.
Pandoc
The universal markup converter
Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library. It can convert from
bibtex(BibTeX bibliography)biblatex(BibLaTeX bibliography)commonmark(CommonMark Markdown)commonmark_x(CommonMark Markdown with extensions)creole(Creole 1.0)csljson(CSL JSON bibliography)csv(CSV table)docbook(DocBook)docx(Word docx)dokuwiki(DokuWiki markup)epub(EPUB)fb2(FictionBook2 e-book)gfm(GitHub-Flavored Markdown), or the deprecated and less accuratemarkdown_github; usemarkdown_githubonly if you need extensions not supported ingfm.haddock(Haddock markup)html(HTML)ipynb(Jupyter notebook)jats(JATS XML)jira(Jira/Confluence wiki markup)json(JSON version of native AST)latex(LaTeX)markdown(Pandoc’s Markdown)markdown_mmd(MultiMarkdown)markdown_phpextra(PHP Markdown Extra)markdown_strict(original unextended Markdown)mediawiki(MediaWiki markup)man(roff man)muse(Muse)native(native Haskell)odt(ODT)opml(OPML)org(Emacs Org mode)rtf(Rich Text Format)rst(reStructuredText)t2t(txt2tags)textile(Textile)tikiwiki(TikiWiki markup)twiki(TWiki markup)vimwiki(Vimwiki)
It can convert to
asciidoc(AsciiDoc) orasciidoctor(AsciiDoctor)beamer(LaTeX beamer slide show)bibtex(BibTeX bibliography)biblatex(BibLaTeX bibliography)commonmark(CommonMark Markdown)commonmark_x(CommonMark Markdown with extensions)context(ConTeXt)csljson(CSL JSON bibliography)docbookordocbook4(DocBook 4)docbook5(DocBook 5)docx(Word docx)dokuwiki(DokuWiki markup)epuborepub3(EPUB v3 book)epub2(EPUB v2)fb2(FictionBook2 e-book)gfm(GitHub-Flavored Markdown), or the deprecated and less accuratemarkdown_github; usemarkdown_githubonly if you need extensions not supported ingfm.haddock(Haddock markup)htmlorhtml5(HTML, i.e. HTML5/XHTML polyglot markup)html4(XHTML 1.0 Transitional)icml(InDesign ICML)ipynb(Jupyter notebook)jats_archiving(JATS XML, Archiving and Interchange Tag Set)jats_articleauthoring(JATS XML, Article Authoring Tag Set)jats_publishing(JATS XML, Journal Publishing Tag Set)jats(alias forjats_archiving)jira(Jira/Confluence wiki markup)json(JSON version of native AST)latex(LaTeX)man(roff man)markdown(Pandoc’s Markdown)markdown_mmd(MultiMarkdown)markdown_phpextra(PHP Markdown Extra)markdown_strict(original unextended Markdown)mediawiki(MediaWiki markup)ms(roff ms)muse(Muse),native(native Haskell),odt(OpenOffice text document)opml(OPML)opendocument(OpenDocument)org(Emacs Org mode)pdf(PDF)plain(plain text),pptx(PowerPoint slide show)rst(reStructuredText)rtf(Rich Text Format)texinfo(GNU Texinfo)textile(Textile)slideous(Slideous HTML and JavaScript slide show)slidy(Slidy HTML and JavaScript slide show)dzslides(DZSlides HTML5 + JavaScript slide show),revealjs(reveal.js HTML5 + JavaScript slide show)s5(S5 HTML and JavaScript slide show)tei(TEI Simple)xwiki(XWiki markup)zimwiki(ZimWiki markup)- the path of a custom Lua writer, see Custom writers below
Pandoc can also produce PDF output via LaTeX, Groff ms, or HTML.
Pandoc’s enhanced version of Markdown includes syntax for tables, definition lists, metadata blocks, footnotes, citations, math, and much more. See the User’s Manual below under Pandoc’s Markdown.
Pandoc has a modular design: it consists of a set of readers, which parse text in a given format and produce a native representation of the document (an abstract syntax tree or AST), and a set of writers, which convert this native representation into a target format. Thus, adding an input or output format requires only adding a reader or writer. Users can also run custom pandoc filters to modify the intermediate AST (see the documentation for filters and Lua filters).
Because pandoc’s intermediate representation of a document is less expressive than many of the formats it converts between, one should not expect perfect conversions between every format and every other. Pandoc attempts to preserve the structural elements of a document, but not formatting details such as margin size. And some document elements, such as complex tables, may not fit into pandoc’s simple document model. While conversions from pandoc’s Markdown to all formats aspire to be perfect, conversions from formats more expressive than pandoc’s Markdown can be expected to be lossy.
Installing
Here’s how to install pandoc.
Documentation
Pandoc’s website contains a full User’s Guide. It is also available here as pandoc-flavored Markdown. The website also contains some examples of the use of pandoc and a limited online demo.
Contributing
Pull requests, bug reports, and feature requests are welcome. Please make sure to read the contributor guidelines before opening a new issue.
License
© 2006-2021 John MacFarlane (jgm@berkeley.edu). Released under the GPL, version 2 or greater. This software carries no warranty of any kind. (See COPYRIGHT for full copyright and warranty notices.)