haskell-comark

The functionality is split across several libraries which are contained in this repo:

• comark -- reexports other libraries
• comark-syntax -- definition of Commonmark's AST;
• comark-parser -- parsing commonmark text and producing AST
• comark-html -- rendering commonmark's AST into HTML
• comark-testutils -- utilities for testing these packages.

Usage

The easiest way to get it running is to use stack. For instructions see Downloading and Installation.

Executable

Executable version lets you play with and test comark easily. To get the executable try doing stack install comark.

$ comark-hs --help
Usage:    comark-hs [OPTIONS*] [FILE*]
Options:
  --to, -t FORMAT  Specify output format (html, native)
  --normalize      Consolidate adjacent text nodes
  --help, -h       Print usage information

$ echo "# Hello, Markdown" | comark-hs
<h1>Hello, Markdown</h1>
$ comark-hs --normalize README.md > README.html
$ comark-hs --to native README.md > README.hs

Library

Initially adding comark dependency should be enough. For more granular imports you might want to add some of the libraries listed above.

To learn how the dependency can be added see Adding dependencies.

import           Data.Text (Text)
import qualified Comark

markdownToHtml :: Text -> Text
markdownToHtml =
  Comark.render . Comark.parse [ Comark.Normalize ]

You can find examples of more complex transformations in comark-examples. And make sure to checkout the docs.

TODO

• Working parser implementation, pass all tests
• Fast and accurate renderer, renders things exactly as in spec.txt.
• Make full use of spec examples. Both renderer and parser are separately tested against the spec relying only on it and the reference implementation (libcmark).
• Handle pathological inputs. Benchmarks are run against markdown-it's samples and over notoriously known nested parenthesis/brackets ("[" * 50000 + "foo" + "]" * 50000)
• Revise module structure, names, and (re-)exports.
• Add to hackage and stackage.
• Document things up.
• Extend ecosystem with additional libraries that ease the integration (comark-blaze, comark-lucid, comark-json)
• Add helpers for processing/walking the AST and examples of typical manipulations.
• Work on extensibility.
• Compile with ghcjs. If performance/size isn't great, consider making bindings to commonmark.js but provide comark-syntax based interface.

License

This library is released under BSD-3-Clause license. See LICENSE for terms and copyright notice.

Custom parser combinators and block structure parser are largely based on the ones found in Cheapskate (Copyright © 2012, 2013, 2014 John MacFarlane).