Hemingway

Hemingway can translate a very rigid subset of LaTeX commands into HTML markup that can then be styled at the user's whim.

The parser was created using Treetop, so it might be useful to consult the Treetop Documentation to learn more about the inner workings.

Throughout you'll notice this character: \\. This is the string represntation of the \ character.

So if your latex is coming from a file you would just write \emph{wookies}, and if it were programatically coming from a string you would write \\emph{wookies}

Installation

Add this line to your application's Gemfile:

gem 'hemingway'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hemingway

Usage

First, instantiate the parser.

parser = Hemingway::Parser.new

Next, chuck some Latex markup into it.

result = parser.parse("do, or do not, there is no \\emph{try}")

Finally, convert the result to html markup.

markup = result.html

If something goes really wrong, the parse method will return nil. If that's the case, you can say something like

parser.failure_reason

to figure out what happened. Hemingway::Parser is a delegator for a Treetop parser, so check out the Treetop Documentation to see what other useful methods you can use in case of something going wrong.

Supported Syntax

Here is a breakdown of supported latex and its markup equivalent. In most examples, I only show the interesting bits of conversion. Note that at the top level, everything is wrapped in

<div class='entry'></div>

but I'm omitting that detail from the examples for brevity. Throughout this, the : operator simply says the LHS maps to the RHS.

Newlines

Delimits paragraphs

wookie\n\nbreakfast : <p>wookie></p><p>breakfast</p>

Maths

Adds math symbols

$\\Gamma$" : &Gamma;
$\\Delta$" : &Delta;
$\\Theta$" : &Theta;
$\\Lambda$" : &Lambda;
$\\Xi$" : &Xi;
$\\Pi$" : &Pi;
$\\Sigma$" : &Sigma;
$\\Upsilon$" : &Upsilon;
$\\Phi$" : &Phi;
$\\Psi$" : &Psi;
$\\Omega$" : &Omega;
$\\alpha$" : &alpha;
$\\beta$" : &beta;
$\\gamma$" : &gamma;
$\\delta$" : &delta;
$\\epsilon$" : &epsilon;
$\\zeta$" : &zeta;
$\\eta$" : &eta;
$\\theta$" : &theta;
$\\iota$" : &iota;
$\\kappa$" : &kappa;
$\\lambda$" : &lambda;
$\\mu$" : &mu;
$\\nu$" : &nu;
$\\xi$" : &xi;
$\\pi$" : &pi;
$\\rho$" : &rho;
$\\varsigma$" : &sigmaf;
$\\sigma$" : &sigma;
$\\tau$" : &tau;
$\\upsilon$" : &upsilon;
$\\phi$" : &phi;
$\\chi$" : &chi;
$\\psi$" : &psi;
$\\omega$" : &omega;

One can also exponentiate something by using math mode:

December 7$^{th}$ : <div class='entry'><p>December 7<sup>th</sup></p></div>

Special Characters

\\# : #
\\$ : $
\\% : %
\\& : &
\\_ : _
\\{ : {
\\} : }

Blocks

You can make lists with itemize, description, or enumerate.

\\begin{itemize}\\item Wookie \\item Jedi \\end{itemize} : <ul><li>Wookie </li><li>Jedi </li></ul>

\\begin{enumerate} \\item Frodo \\item Sam \\end{enumerate} : <ol><li>Frodo </li><li>Sam </li></ol>

\\begin{description} \\item Ginger-Nut \\item Turkey \\end{description} : <dl><dd>Ginger-Nut </dd><dd>Turkey </dd></dl>

Add labels to a list with \item[label]:

\\begin{itemize}\\item[bros] before hoes \\item \\n [chicks] before dicks \\end{itemize} : <ul><li><span class='list-label'>bros</span> before hoes </li><li><span class='list-label'>chicks</span> before dicks </li></ul>

\\begin{description} \\item [Frodo] Intrepid Adventurer \\item [Sam] Faithful Companion \\end{description} : <dl><dd><dt>Frodo</dt> Intrepid Adventurer </dd><dd><dt>Sam</dt> Faithful Companion </dd></dl>

Go ahead, nest lists in all sorts of interesting ways. No reason you couldn't chuck some empahsized text in a label either.

Enter in preformatted text:

\\begin{verbatim} don't  we  \n \n all wish \n \n   for a little sleep? \\end{verbatim}") : <pre>don't  we  \n \n all wish \n \n   for a little sleep? </pre>

Footnotes

Putting in a bunch of footnotes inline with your content is an awesome idea. All footnotes within an entry will be yanked out, linked with an anchor tag, and placed after all paragraphs in the entry. Naturally you can put just about whatever you want in a footnote (save another footnote).

I might have made a bad assumption here and used the <sup> tag for the footnote number because it assumes formatting, something I've been trying to avoid. If you'd like that assumption removed, you're just a pull request away.

For example this latex markup:

So we met up with Han and saw his ship, The Millennium Falcon\footnotetotal piece of junk. I had no idea how that thing was supposed to get us to Alderaan\footnoteof the \emph{hidden rebel base}.

On board we found homely accommodations including a Dejarik\footnotelike chess set that I indulged in with Chewbacca\footnotecarpety first mate.

Renders to this html:

<div class='entry'>
  <p>
    So we met up with Han and saw his ship, The Millenium Falcon<a href='#footnote1'><span class='inline-footnote-number'><sup>1</sup></span></a>. I had no idea how that thing was supposed to get us to Alderaan<a href='#footnote2'><span class='inline-footnote-number'><sup>2</sup></span></a>.
  </p>
  <p>
    On board we found homely accommodations including a Dejarik<a href='#footnote3'><span class='inline-footnote-number'><sup>3</sup></span></a> set that I indulged in with Chewbacca<a href='#footnote4'><span class='inline-footnote-number'><sup>4</sup></span></a>.
  </p>

  <div id='footnote1' class='footnote'>
    <span class='footnote-number'><sup>1</sup></span>a total piece of junk
  </div>

  <div id='footnote2' class='footnote'>
    <span class='footnote-number'><sup>2</sup></span>location of the <em>hidden rebel base</em>
  </div>

  <div id='footnote3' class='footnote'>
    <span class='footnote-number'><sup>3</sup></span>much like chess
  </div>

  <div id='footnote4' class='footnote'>
    <span class='footnote-number'><sup>4</sup></span>Han's carpety first mate
  </div>

</div>

And looks like this:

So we met up with Han and saw his ship, The Millennium Falcon¹. I had no idea how that thing was supposed to get us to Alderaan².

On board we found homely accommodations including a Dejarik³ set that I indulged in with Chewbacca⁴.

¹a total piece of junk

²location of the hidden rebel base

³much like chess

⁴Han's carpety first mate

I've added a timestamp onto footnote hrefs and ids to make the unique incase you are parsing multiple entries on a given HTML document.

Block Quotes

Pretty standard. You can put anything in there except a footnote. That seemed excessive.

\\begin{quote}
Have you guys ever heard the song \\emph{Blow} by \\emph{MILF}?
\\end{quote}

maps to

<blockquote>
  <p>
    Have you guys ever heard the song <em>Blow</em> by <em>MILF</em>?
  </p>
</blockquote>

Centering Text

\\begin{center} Dromiceiomimus \\end{center} : <div class="center">Dromiceiomimus</div>

Inline Right Justification

The love, \\hfill Will