#The LaTeXC class#
\hatex has two different interfaces. One uses blocks as \{Monoid\} elements and the other
as \{Monad\} actions. If we want to keep both interfaces we have two choices: to duplicate
function definitions\f
This was the approach taken in \hatex 3 until the version 3.3, where the \{LaTeXC\} class was included.
\f
or to have a typeclass which unifies both interfaces. Since duplicate definitions is a hard work
and can arise problems\f
In fact, we had a problem with \hatex-meta, the program that automatically generated the duplicated functions.
The problem was described in a blog post: <http://deltadiaz.blogspot.com.es/2012/04/hatex-trees-and-problems.html>.
\f, we took the second alternative and defined the \{LaTeXC\} typeclass. Both \{LaTeX\} and \{LaTeXT m a\} are
instances of \{LaTeXC\} (the second one is a little tricky), so every function in \hatex is defined using the
typeclass. This way, we have both interfaces with a single import, without being worry about maintaining
duplicated code. The cost is to have class constraints in type signatures. But these constraints are only required
in the package. At the user level, you choose your interface and write type signatures in consequence.