meg.js

meg.js is a parsing expression parser for HTML and Markdown. It is based on the insanely great peg.js by David Majda (@dmajda).

Note: While the transformatiom from Markdown to HTML is lossless, parsing HTML to Markdown is not. meg.js is designed to be used to help save data inside contenteditable elements in a (hopefully) more universal format.

Gettings Started

You have to install node.js if you haven't already.

After you have setup node run npm install. When all packages have been installed you can run:

• grunt or grunt release to build the project (minified)
• grunt test to run the test suite (via Karma).
• grunt dev will build the project unminified.
• grunt tdd if you want to write new tests and work on the project.

Grammar

For reference here is the grammar used to transform HTML to Markdown:

Char <- /[^<]/
LowerCase <- /[a-z]/
TagName <- LowerCase+
TextNode <- Char*
StartTag <- '<' TagName '>'
ClosingTag <- '</' TagName '>'
Element <- StartTag Content ClosingTag
Content <- Element / TextNode

while Content is the only starting expression. Char and LowerCase are terminal symbols.

Example Usage

var parser = meg(),
    result = parser.fromHTML('<div>This is an <em>example</em>!</div>');

    // result is "This is an *example*!"

You can also pass additional mutation rules to meg.js:

var parser = meg({ exp: /^sup$/, start: '^', end: '' }),
    result = parser.fromHTML('I am n<sup>2</sup>.');

    // result is "i am n²."

Warning: This feature is experimental, because it is not tested! For more informations see the tests.