CSS: style.css
LaTeX_use_listings: true
html_use_syntax: true
use_numbered_headers: true

Mar**u**k**u**: a Markdown interpreter 
======================================

[Maruku][] is a Markdown interpreter written in [Ruby][].

[maruku]: <http://maruku.rubyforge.org/>

Maruku allows you to write in an easy-to-read-and-write syntax, like this:

> [This document in Markdown](http://maruku.rubyforge.org/maruku.md)

Then it can be translated to HTML:

> [This document in HTML](http://maruku.rubyforge.org/maruku.html)
	
or LaTeX, which is then converted to PDF:

> [This document in PDF](http://maruku.rubyforge.org/maruku.pdf)

Maruku implements:

* the original [Markdown syntax][] 
([HTML](http://maruku.rubyforge.org/markdown_syntax.html) or
[PDF](http://maruku.rubyforge.org/markdown_syntax.pdf), translated by Maruku).

* all the improvements in [PHP Markdown Extra][]. 

* a new [meta-data syntax](#meta)

* some ideas from [MultiMarkdown][]
  * attributes in image links

The [test directory][tests] is quite messy but it shows every capability.

[tests]: http://maruku.rubyforge.org/tests/

### Authors ###

Maruku has been developed so far by [Andrea Censi][].
Contributors are most welcome!

[Andrea Censi]: http://www.dis.uniroma1.it/~acensi/

* * *

Table of contents: (**auto-generated by Maruku!**)

@toc 

* This list will contain the toc (it doesn't matter what you write here)

* * *

@ class: head

Download       {#download}
--------

The development site is <http://rubyforge.org/projects/maruku/>.

Install with:

	$ gem install maruku

Released files can also be seen at <http://rubyforge.org/frs/?group_id=2795>.

Anonymous access to the repository is possible with:

	$ svn checkout svn://rubyforge.org/var/svn/maruku

If you want commit access to the repository, just create an account on Rubyforge and [drop me a mail][drop].

[drop]: http://www.dis.uniroma1.it/~acensi/contact.html
[gem]: http://rubygems.rubyforge.org/

### Bugs report ###

Use the [tracker](http://rubyforge.org/tracker/?group_id=2795)
or [drop me an email][drop].

Usage
--------

This is the basic usage:

@ lang: ruby

	require 'rubygems'
	require 'maruku'

	doc = Maruku.new(markdown_string)
	puts doc.to_html

The method `to_html` outputs only an HTML fragment, while the method `to_html_document` outputs a complete XHTML 1.0 document:

@ lang: ruby

	puts doc.to_html_document
	
You can have the REXML document tree with:

@ lang: ruby

	tree = doc.to_html_document_tree

### From the command line ###

There are two command-line programs installed: `maruku` and `marutex`.

* `maruku` converts Markdown to HTML:

  	$ maruku file.md  # creates file.html

* `marutex` converts Markdown to LaTeX, then calls `pdflatex` to 
transform to PDF:

  	$ marutex file.md  # creates file.tex and file.pdf


Examples of PHP Markdown Extra syntax {#extra}
-------------------------------------

* tables

  	Col1 | Very very long head | Very very long head|
  	-----|:-------------------:|-------------------:|
  	cell | center-align        | right-align        |

  @ class: example

  Col1 | Very very long head | Very very long head|
  -----|:-------------------:|-------------------:|
  cell | center-align        | right-align        |


* footnotes [^foot]

  	* footnotes [^foot]

  	[^foot]: I really was missing those.

[^foot]: I really was missing those.

* Markdown inside HTML elememnts

@lang: html

  	<div markdown="1" style="border: solid 1px black">
  	   This is a div with Markdown **strong text**
  	</div>

  <div markdown="1" style="border: solid 1px black">
     This is a div with Markdown **strong text**
  </div>


* header ids
      ## Download ##     {#download}
  For example, [a link to the download](#download) header.

  Note that you can use also the new [meta-data syntax](#meta) for the same purpose:

  	@ id: download 
  	## Header ##     

* definition lists

  	Definition list
  	: something very hard to parse

  Definition list
  : something very hard to parse

* abbreviations or ABB for short.

*[ABB]: Simply an abbreviation



Maruku and Bluecloth          {#maruku-and-bluecloth}
--------------------

The other Ruby implementation of Markdown is [Bluecloth][]. 

Maruku is much different in philosophy from Bluecloth: the biggest 
difference is that *parsing* is separated from *rendering*.
In Maruku, an in-memory representation of the Markdown
document is created. Instead, Bluecloth mantains the document in
memory as a String at all times, and does a series of `gsub` 
to transform to HTML.

[^1]: "a different philosophy" stands for "ugly" `:-)`

The in-memory representation makes it very easy to export
to various formats (altough, for, now)

Other improvements over Bluecloth:

* the HTML output is provided also as a `REXML` document tree.

* PHP Markdown Syntax support.

[ruby]: http://www.ruby-lang.org
[bluecloth]: http://www.deveiate.org/projects/BlueCloth
[Markdown syntax]: http://daringfireball.net/projects/markdown/syntax
[PHP Markdown Extra]: http://www.michelf.com/projects/php-markdown/extra/


New meta-data syntax {#meta}
--------------------

Maruku implements a syntax that allows to attach "meta" information
to objects.

### Meta-data for the document ###

Meta-data for the document itself is specified through the use
of email headers:

	Title: A simple document containing meta-headers
	CSS: style.css
	
	Content of the document

When creating the document through 

@ lang: ruby

	Maruku.new(s).to_html_document

the title and stylesheet are added as expected.

Meta-data keys are assumed to be case-insensitive.

### Meta-data for elements ###

Maruku introduces a new syntax for attaching metadata to paragraphs, tables, and
so on.

For example, consider the creation of two paragraphs:

	Paragraph 1 is a warning.

	Paragraph 2

Now you really want to attach a 'class' attribute to the paragraphs (for
example for CSS styling). Maruku allows you to use:

	@ class: warning
	Paragraph 1 is a warning

	Paragraph 2
	

You can add more by separating with a `;`:

	@ class: warning; id: warning1
	Paragraph 1 is a warning

A meta-data declaration is composed of 

1. newline
2. an at-symbol `@`
3. a series of name-value pairs. Each name-value is separated 
   by a colon `:`, pairs are separated by semi-colons `;` 

Many declaration can be used, and they refer to _the following_ object:

	@ class: warning
	@ id: warning1
	Paragraph 1 is a warning

These can also be separated by newlines:

	@ class: warning

	@ id: warning1

	Paragraph 1 is a warning


### Shortcuts ###

This:

	@ .xyz
	Paragraph

is equivalent to:

	@ class: xyz
	Paragraph

This:

	@ #xyz
	Paragraph

is equivalent to:

	@ id: xyz
	Paragraph

Also, if the value is not present, it defaults to `true`:

	@ test

	This paragraph has the attribute `test` set to `true`.

* * *



@ #metalist

### List of meta-data  ### 

[listings]: http://www.ctan.org/tex-archive/macros/latex/contrib/listings/

**`title`, `subject`**
: (document) Sets the title of the document (HTML: used in the `TITLE` element).

**`use_numbered_headers`**
: (document) If `true`, headers are numbered (just like this document). Default is `false`.

**`css`**
: (document, HTML) Url of stylesheet.

**`html_use_syntax`**
: (document, HTML) If set, use the [Ruby `syntax` library][syntax] to add source highlighting.

**`latex_use_listings`**
: (document, LaTeX) If set, use the fancy [`listings` package][listings] for better displaying code blocks.
     
     If not set,  use standard `verbatim` environment.

**`style`, `id`, `class`**
: (any block object, HTML) Standard CSS attributes are copied.

**`lang`**
: (code blocks) Name of programming language (`ruby`) for syntax highlighting.

      Default for this is `code_lang` in document.
      
      Syntax highlighting is delegated to the [`syntax` library][syntax] for
      HTML output and to the [`listings` package][listings] for LaTeX output.


**`code_show_spaces`**
: Shows tabs and newlines (default is read in the document object).

**`code_background_color`**
: Background color for code blocks. (default is read in the document object).

    The format is either a named color (`green`, `red`) or a CSS color
    of the form `#ff00ff`. 

    * for **HTML output**, the value is put straight in the `background-color` CSS 
      property of the block.

    * for **LaTeX output**, if it is a named color, it must be a color accepted
      by the LaTeX `color` packages. If it is of the form `#ff00ff`, Maruku
      defines a color using the `\color[rgb]{r,g,b}` macro. 

      For example, for `#0000ff`, the macro is called as: `\color[rgb]{0,0,1}`.

[syntax]: http://syntax.rubyforge.org/


### Examples ###

An example of this is the following:

@ code_show_spaces
	@ code_show_spaces; code_background_color: green
	
		 One space
		  Two spaces
			 	Tab, space, tab
					Tab, tab, tab and all is green!

That will produce:

@ code_show_spaces
@ code_background_color: green

	 One space
	  Two spaces
		 	Tab, space, tab
				Tab, tab, tab and all is green!

Example with css-style color:

	@ code_background_color: #455678

		A strange color

produces:

@ code_background_color: #455678

	A strange color

Or highlighting (does not work well yet):

	@ lang: xml
		<div style="text-align:center">Div</div>

produces:

@ lang: xml
	<div style="text-align:center">Div</div>



* * *

Other Features
--------------

### Automatic generation of the table of contents ###

If you create a list, and the set the `toc` attribute, when rendering
Maruku will create an auto-generated table of contents.

	@ toc
	* This will become a table of contents

You can see an example of this at the beginning of this document.

### This header contains *emphasis* **strong text** and `code` ####

Note that this header contains formatting and it still works, also
in the table of contents.

TODO list
--------------------------


* Export to HTML
  1. Add `-split` options to `maruku` that splits the document over multiple 
     pages. 

     This should require the possibility of specifying a template for navigational
     elements. Investigate template engine.

  2. Include RubyPants

* Export to PDF 
  * support for images

* Export to Markdown (pretty-printing)


Future developments                              {#future}
-------------------

I think that [Pandoc][] and [MultiMarkdown][] are very cool projects.
However, they are written in Haskell and Perl, respectively. 
I would love to have an equivalent in Ruby.


[Pandoc]: http://sophos.berkeley.edu/macfarlane/pandoc/
[MultiMarkdown]: http://fletcher.freeshell.org/wiki/MultiMarkdown


### A syntax for specifying meta-data for span-level elements ###

Maybe something like this:
  
	This is a paragraph. The second line of this paragraph has
	the last element {with meta data}@ class: important_span
	and the paragraph continues...

So the idea is:

* Only elements at the end of the line can have meta data.
* Syntax is:
  1. Opening brace `{`.
  2. Any string that does not contain the sequence `}@`.
  3. Closing brace and at-symbol `}@`.
  4. Attributes specification like the block-level metadata.

Other examples:

	Lorem ipsum dolor sit amet, consectetuer adipiscing 
	elit. Donec sit amet sapien vitae augue {interdum hendrerit.}@  id: special
	Maecenas tempor ultrices nisl. Praesent laoreet tortor sit
	amet est. Praesent in nisl eu libero sodales bibendum.

Or, we could allow metadata specified **after the text**.
In the following, three fragments are marked as "special", 
and, after their containing block-level elements, their 
attributes are set:

	Lorem ipsum dolor sit @{amet}, consectetuer adipiscing 
	elit. Donec sit amet sapien vitae augue @{interdum hendrerit.}
	Maecenas tempor ultrices nisl. @{Praesent laoreet tortor sit
	amet est.} Praesent in nisl eu libero sodales bibendum.

	@{1} id: amet
	@{2} style: "font-style: bold"
	@{3} class: warning

We can be much liberal in the syntax. For example, instead of 
numeric references to the part in the text, we could write:

	Lorem ipsum dolor sit @{amet}, consectetuer adipiscing 
	elit. Donec sit amet sapien vitae augue @{interdum hendrerit.}
	Maecenas tempor ultrices nisl. @{Praesent laoreet tortor sit
	amet est.} Praesent in nisl eu libero sodales bibendum.

	@{amet} id: amet
	@{interdum ...} style: "font-style: bold"
	@{Praesent ...} class: warning

with `...` acting as a wildcard, to match a long phrase (`{	Praesent laoreet tortor sit amet est.}`) without specifying the full text.

I feel this is very readable and not intrusive. But then again,
subjective tastes vary. Let me know of any comments and suggestions.
I want to wait for feedback before implementing this.

### A syntax for commenting parts of the document ###

	This is a paragraph
	% This is a comment

Or `%` on a line by itself comments the following block:

	% The following paragraph is ignored
	
	%
	Lorem ipsum dolor sit amet, consectetuer adipiscing 
	elit. Donec sit amet sapien vitae augue interdum hendrerit.
	Maecenas tempor ultrices nisl. Praesent laoreet tortor sit
	amet est. Praesent in nisl eu libero sodales bibendum.

	This paragraph is not ignored.

### A syntax for adding math ###

Something inspired from LaTeX should be familiar to all:

	This is inline math: $\alpha$


	This is an equation with label:

	$ \alpha = \beta + \gamma  $        (eq:1)

	This is a reference to equation: please see (eq:1)