## Monday, February 20, 2012

### HaTeX: Chapter 3.2

It's time for a new release of HaTeX: the version 3.2, as announced in my previous post. I'm glad each time I see my library get better. Although the major version is increased again, I expect backwards compatibility, in spite of the changes done in some type signatures. I have tried to get previous code working.

Get HaTeX 3.2 from Hackage: http://hackage.haskell.org/package/HaTeX-3.2.

This is how HaTeX has changed this time.

The LaTeX Parser

It makes me happy to get working a parser of LaTeX. I have tested it with some examples (for instance, with the "fibs.hs" example, included in the library) with a reasonable output. Anyway, the parser is not mature yet. Future working on it will be done when a bugged output is found parsing some LaTeX code.

Greek alphabet

The AMSMath module is still very incomplete, but now it contains the entire greek alphabet.

The graphicx package

A new module with a new LaTeX package has been added. This time was for the graphicx package. The point here is to get all to be done with types, wherever possible. The way to achieve this is to define datatypes that will force you to put correct arguments to the functions. So the includegraphics function receives a [IGOption] and a FilePath as arguments, where each IGOption is a typed representation of each valid argument for includegraphics.

Changes in documentclass

Until now, documentclass function had type:

documentclass :: [LaTeX] -> String -> LaTeX

So if you want to set the font size to 12pt, you had to do:

documentclass [rendertex $Pt 12] or to do the trick: documentclass ["12pt"] which looks quite dirty. Following my all-typed approach, I defined a new datatype (ClassOption) for documentclass arguments. This way, the former get done like this: documentclass [FontSize$ Pt 12]

I find this more correct. Anyway, the second way still work, while the first one don't.

Other minor changes

Other minor changes have been done, like GHC 7.4 compatibility (thanks to Alexey Khudyakov) or addition of some new functions. To view a complete list see the commit history of the library.