The (Lua)LaTeX Highlighter

Package dependencies

The current version of the LuaLaTeX highlighter is based on the following packages:

xcolor, for basic color support.
lua-ul, for proper background highlighting.
listings, to hold the listings themselves.
tcolorbox, to fix an annoying problem with extra space appearing between listing lines in some circumstances.

Fonts

The default mono font does not support boldface. If you need boldface in your highlighting schemas (the default ones supplied with the Rexx Parser use boldface), you should use a different mono font. The Hack font, for example, available at https://sourcefoundry.org/hack/, seems to produce decent results.

Listing width

You will most probably need to adjust the size of your font, depending on the page size and the number of characters you want displayed on the largest line. The following style definition allows for exactly 80 characters per line, when using the Hack font and an A4 paper size:

\lstdefinestyle{rexx}
{
    basicstyle=\fontsize{8.0pt}{11.0pt}\selectfont\color{white}\ttfamily
}

Commands

The LuaLaTeX highlighting framework defines a single command. The exclamation mark is being used as an escape character, and the command is needed when the exclamation appears in a Rexx program.

\newcommand{\textexclamup}{!}

Selecting LaTeX mode

The -l and --latex options of the highlight utility will select the LuaLaTeX highlighter. The highlighter output will be a complete lstlisting environment.

Example output

\begin{lstlisting}[ style=rexx, frame=single, escapechar=!, backgroundcolor={\color[HTML]{000000}} ]
!\textcolor[HTML]{cccc00}{~~}\textcolor[HTML]{ffcc00}{\textit{.environment}}\textcolor[HTML]{ff0000}{\~{}}\textcolor[HTML]{b8fa5c}{\textit{test.2.x}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{dddddd}{\textbf{=}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{ff66ff}{test.}\textcolor[HTML]{33cccc}{2}\textcolor[HTML]{ff0000}{.}\textcolor[HTML]{ff66ff}{\textit{x}}\textcolor[HTML]{cccc00}{~~~~~~}\textcolor[HTML]{00cc00}{\textit{--~Method~call,~compound~variable...}}!
!\textcolor[HTML]{cccc00}{~~}\textcolor[HTML]{dddddd}{\textbf{Exit}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{ffcc00}{\textit{.test.2.x}}\textcolor[HTML]{cccc00}{~~~~~~~~~~~~~~~~~~~~~~~~}\textcolor[HTML]{00cc00}{\textit{--~...and~environment~variable}}!
\end{lstlisting}

An complete sample Tex file

\documentclass[12pt,a4paper,english]{article}
\usepackage{xcolor}
\usepackage{lua-ul}
\usepackage{fontspec}
\setmonofont{Hack}
\usepackage{listings}
\usepackage[many]{tcolorbox}

\lstdefinestyle{rexx}
{
    basicstyle=\fontsize{8.0pt}{11.0pt}\selectfont\color{white}\ttfamily
}

\begin{document}

\newcommand{\textexclamup}{!}

\begin{lstlisting}[ style=rexx, frame=single, escapechar=!, backgroundcolor={\color[HTML]{000000}} ]
!\textcolor[HTML]{cccc00}{~~}\textcolor[HTML]{ffcc00}{\textit{.environment}}\textcolor[HTML]{ff0000}{\~{}}\textcolor[HTML]{b8fa5c}{\textit{test.2.x}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{dddddd}{\textbf{=}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{ff66ff}{test.}\textcolor[HTML]{33cccc}{2}\textcolor[HTML]{ff0000}{.}\textcolor[HTML]{ff66ff}{\textit{x}}\textcolor[HTML]{cccc00}{~~~~~~}\textcolor[HTML]{00cc00}{\textit{--~Method~call,~compound~variable...}}!
!\textcolor[HTML]{cccc00}{~~}\textcolor[HTML]{dddddd}{\textbf{Exit}}\textcolor[HTML]{cccc00}{~}\textcolor[HTML]{ffcc00}{\textit{.test.2.x}}\textcolor[HTML]{cccc00}{~~~~~~~~~~~~~~~~~~~~~~~~}\textcolor[HTML]{00cc00}{\textit{--~...and~environment~variable}}!
\end{lstlisting}

\end{document}