shamansir/mdown-parse-pegjs

:raised_hand: Parsing Markdown with PegJS

Markdown parser with PegJS

A Markdown parser written in JavaScript, generated with PEG grammar. Currently, in progress.

This is a component of xtd project, but I plan to finish developing it separately and then merge the result there. (So, the most part of its development history is located there).

In fact, it is a translation of PegC Markdown parser to JavaScript. But in the end, there are a lot differences in the sources and result.

The both C variant and JS (this) variant build a tree of parsed document elements, including their offsets and additional data required for generating some HTML result or hightlighting a syntax in some JavaScript implementation.

Sources

• Markdown by John Gruber, a great documents' syntax agreement
• PegJS by David Majda, a JavaScript parsers generator using PEG-like grammars
• My Customized PegJS Implementation with chunk variables inside actions and merged with PegJS predicate fix.
• PegC GUI-oriented Markdown parser by Ali Rantakari, the place where I've found a parser and copied it and now I am modifying it for JavaScript
• PegC Markdown parser by John MacFarlane, the version the previous author adapted to implement his GUI-oriented version and in fact the actual and the main PegC parser (and I am taking parts from there to include new things here)
• PegC by Stephan Beal, itself
• PegHS Markdown parser, again by John MacFarlane, if you are interested
• Codemirror 2, the nerdy JS-written any-language source-code editor I plan to integrate with
• MDTest 1.1 by Michel Fortin

The Development State

Finished

• Inlines: Strong, Em, Code
• Html Blocks, Html entities
• Headings
• Horizontal Rules
• Paragraphs
• Top-level Lists
• Top-level verbatims
• Links, all modifications
• Images, all modifications
• Oh, all that stuff except complex lists

Not finished

(They were working some not ideal way, but I am currently refactoring this part)

• Nested lists and blocks inside them
• Different extra syntax
• Search over the new stuff in PegC Markdown parser implementation
• Test over for for Markdown Syntax
• Check out [Markdown Gotchas][]
• Test with MDTest 1.1 by Michel Fortin
• Support Markdown Extra

So currently, the lists are parsed ok, but I plan to modify their rules to support complex indentations.

Which Way the Result Looks Like

When parsing a MarkDown document, you get a JavaScript Object containing the document tree in Markdown terms. I'll make a detailed description when I'll finish an implementation.

Competitors

Just a JS-ones:

• Showdown by Corey Innis
• MarkdownJS by Dominic Baggott
• Pagedown used at StackOverflow
• WMDEditor used at StackOverflow

To Develop

Install last node.js version (v0.5.8+)

Install npm

Run in node directory (or with -g):

npm install pegjs
npm install [email protected] # or higher

cd ~/Worktable # (for example)
git clone [email protected]:shamansir/pegjs.git
cd ./pegjs
jake build
node test/run
ln -sf ~/Worktable/pegjs <nodejs-location>/lib/node_modules
ln -s <nodejs-location>/lib/node_modules ./node_modules # optional, if pegjs module not found
cd ~/Workspace # (for example) 
git clone [email protected]:shamansir/mdown-parse-pegjs.git
cd ./mdown-parse-pegjs
node ./test-mdown-parser-with-node.js