# fox-listings — Listings language definition for COSYScript (COSY INFINITY)

A LaTeX package providing `listings` language support for
COSYScript, the programming language of
[COSY INFINITY](https://cosyinfinity.org), a beam dynamics code
using high-order differential-algebraic (DA) transfer maps and
methods.  COSYScript source files use the `.fox` extension; this
package uses `FOX` as the `listings` language identifier.

## Features

- Complete keyword coverage: control flow, intrinsic functions,
  DA procedures, beam physics commands, graphics, constants
- Case-insensitive matching (FOX is case-insensitive)
- Nested `{...}` comment support
- Single-quoted string literals
- Two predefined styles: `FOXcolor` (screen) and `FOXmono` (print)
- Six keyword groups with independent styling

## Usage

```latex
\usepackage{fox-listings}

\begin{lstlisting}[style=FOXcolor]
INCLUDE 'COSY' ;
VARIABLE X 1 ;
X := SIN(0.5) ;
WRITE 6 X ;
END ;
\end{lstlisting}
```

Or with just the language (bring your own style):

```latex
\begin{lstlisting}[language=FOX]
...
\end{lstlisting}
```

## Installation

**From CTAN** (when available): Install via your TeX distribution's package
manager (`tlmgr install fox-listings`).

**Manual install**: Copy `fox-listings.sty` to your local texmf tree and
refresh the filename database:

```
cp fox-listings.sty $(kpsewhich -var-value=TEXMFHOME)/tex/latex/fox-listings/
texhash
```

**Per-project**: Place `fox-listings.sty` alongside your `.tex` file — no
installation needed.

## Requirements

- `listings` package
- `xcolor` package (loaded automatically)

## Known limitations

The `listings` package does not highlight in-code numbers for user-defined
languages.  Fortran-style `D`-exponent notation (e.g., `1.5D-3`) and
standard decimal literals (`0.5`, `1E-3`) are rendered in the base style.
This is a `listings` limitation, not a `fox-listings` bug.

The `listings` tokenizer has no scope or context awareness, so a user variable
that shares its name with a keyword (e.g., `OV`, `MQ`, `CR`) will be
highlighted as a keyword.

## License

This material is subject to the LaTeX Project Public License 1.3c.
See https://www.latex-project.org/lppl/lppl-1-3c/

## Author

Eremey Valetov — https://github.com/evvaletov

## Links

- COSY INFINITY: https://cosyinfinity.org
- foxkernel (Jupyter kernel for FOX): https://github.com/evvaletov/foxkernel
- cosy-vim (Vim/Neovim syntax): https://github.com/evvaletov/cosy-vim