uvlhighlight.sty

%% File: uvlhighlight.sty
%% Author: José Miguel Horcas
%% Description: A LaTeX package to display UVL (Universal Variability Language) code.
%% Version: 1.3

% --- 1. Package Identification ---
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{uvlhighlight}[2026/04/13 v1.3 UVL Syntax Highlighting]

% --- 2. Dependencies ---
\RequirePackage{listings} % For code formatting engine
\RequirePackage{xcolor}   % For color management
\RequirePackage{xspace}  % For space in UVL command

% --- 3. Font Handling Logic ---
% Toggle to control font loading (True by default).
\newif\ifuvlhighlight@loadfont\uvlhighlight@loadfonttrue          % Load default font: yes
\newif\ifuvlhighlight@beramono\uvlhighlight@beramonotrue          % Load beramono by default: yes
\newif\ifuvlhighlight@inconsolata\uvlhighlight@inconsolatafalse   % Use inconsolata?: no

% --- 4. Default Color Palette (Standard Theme) ---
\newcommand{\uvlbasiccolor}{\color{black}} 

% Color Definitions (HTML format for consistency)
\definecolor{UVLKeyword}{HTML}{A586C0}       % Purple
\definecolor{UVLType}{HTML}{A586C0}          % Purple
\definecolor{UVLString}{HTML}{CE723B}        % Red/Orange
\definecolor{UVLComment}{HTML}{529955}       % Green
\definecolor{UVLAttribute}{HTML}{4E94CE}     % Light Blue
\definecolor{UVLUserAttribute}{HTML}{4E94CE} % Light Blue
\definecolor{UVLConstraint}{HTML}{D0A343}    % Gold
\definecolor{UVLFeature}{HTML}{000000}       % Black
\definecolor{UVLOperator}{HTML}{000000}      % Black
\definecolor{UVLNumber}{HTML}{000000}        % Black
\definecolor{UVLDelimiter}{HTML}{000000}     % Black
\definecolor{UVLBackground}{HTML}{FFFFFF}     % White

% --- 5. Options Handling ---

% Option: nofont (Disable automatic font loading)
\DeclareOption{nofont}{
    \uvlhighlight@loadfontfalse 
    \uvlhighlight@beramonofalse
    \uvlhighlight@inconsolatafalse
}

% Option: beramono (default, defined for clarity)
\DeclareOption{beramono}{
    \uvlhighlight@beramonotrue
    \uvlhighlight@inconsolatafalse
}

% Option: inconsolata
\DeclareOption{inconsolata}{
    \uvlhighlight@inconsolatatrue
    \uvlhighlight@beramonofalse
}

% Option: bw (Black & White - Optimized for printing)
\DeclareOption{bw}{
    \definecolor{UVLKeyword}{HTML}{000000}
    \definecolor{UVLType}{HTML}{000000}
    \definecolor{UVLString}{gray}{0.3}
    \definecolor{UVLComment}{gray}{0.5}
    \definecolor{UVLAttribute}{HTML}{000000} 
    \definecolor{UVLUserAttribute}{HTML}{000000}
    \definecolor{UVLConstraint}{HTML}{000000} 
    \definecolor{UVLFeature}{gray}{0.1}
    \definecolor{UVLBackground}{white}
    \renewcommand{\uvlbasiccolor}{\color{black}}
}

% Option: flamapy (Custom Theme)
\DeclareOption{flamapy}{
    \definecolor{UVLKeyword}{HTML}{0000FF}    
    \definecolor{UVLDelimiter}{HTML}{0431FA}  
    \definecolor{UVLString}{HTML}{A31515}     
    \definecolor{UVLNumber}{HTML}{098658}     
    \definecolor{UVLComment}{HTML}{008000}    
    \definecolor{UVLConstraint}{HTML}{D0A343} 
    \definecolor{UVLType}{HTML}{000000}
    \definecolor{UVLAttribute}{HTML}{000000}
    \definecolor{UVLUserAttribute}{HTML}{000000}
    \definecolor{UVLBackground}{white}
    \renewcommand{\uvlbasiccolor}{\color{black}}
}

% Option: uvls (Visual Studio / Dark Theme)
\DeclareOption{uvls}{
    \definecolor{UVLFeature}{HTML}{9EDCFA}    
    \definecolor{UVLKeyword}{HTML}{C586BF}    
    \definecolor{UVLType}{HTML}{4EC9B0}       
    \definecolor{UVLString}{HTML}{CD9077}     
    \definecolor{UVLComment}{HTML}{58894B}    
    \definecolor{UVLAttribute}{HTML}{41C6F6}  
    \definecolor{UVLUserAttribute}{HTML}{41C6F6}
    \definecolor{UVLConstraint}{HTML}{C2C385} 
    \definecolor{UVLOperator}{HTML}{FFFFFF}    
    \definecolor{UVLNumber}{HTML}{B5CEA8}     
    \definecolor{UVLDelimiter}{HTML}{EECE0C}  
    \definecolor{UVLBackground}{HTML}{000000} 
    \renewcommand{\uvlbasiccolor}{\color{UVLFeature}}
}

\ProcessOptions\relax

% --- 6. Implementation & Execution ---

% Safe loading of fontenc (T1) to avoid conflicts (needed for symbol such as < > |)
\@ifpackageloaded{fontenc}{}{%
    \RequirePackage[T1]{fontenc}%
}

% Logic for font loading
\ifuvlhighlight@loadfont
    \ifuvlhighlight@beramono
        \RequirePackage[scaled=0.85]{beramono}
        \renewcommand{\bfdefault}{b} % bold is 'b' for Beramono, not 'bx'
    \else\ifuvlhighlight@inconsolata
        \RequirePackage[varqu]{zi4} % zi4 is Inconsolata
    \fi\fi
\else
    % User choose 'nofont'
    \RequirePackage{lmodern}
\fi


% --- 7. Language Definition (Internal) ---
\lstdefinelanguage{UVLInternal}{
  % -- Group 1: Structure Keywords --
  morekeywords={alternative, or, optional, mandatory, features, constraints, constraint, cardinality, imports, as, include, true, false, attributes, xor, namespace},
  % -- Group 2: Modifiers --
  morekeywords=[2]{abstract},
  % -- Group 3: User Defined (Empty by default) --
  morekeywords=[3]{},
  % -- Group 4: Math/Aggr Functions --
  morekeywords=[4]{sum, avg, ceil, floor, len},
  % -- Group 5: Types --
  morekeywords=[5]{Boolean, Integer, Real, String},
  % -- General Settings --
  sensitive=true,                % Case sensitive syntax (Capitalization matters)
  % -- Comments --
  morecomment=[l]{//},           % Line comment style (//)
  morecomment=[s]{/*}{*/},       % Block comment style (starts /* ends */)
  % -- Strings --
  morestring=[b]',               % Strings defined by single quotes
  % -- Styles --
  keywordstyle=\color{UVLKeyword}\bfseries,      % Style for Group 1 (Structure)
  keywordstyle=[2]\color{UVLAttribute},          % Style for Group 2 (Modifiers)
  keywordstyle=[3]\color{UVLUserAttribute},      % Style for Group 3 (User Attributes)
  keywordstyle=[4]\color{UVLConstraint}\bfseries,% Style for Group 4 (Functions)
  keywordstyle=[5]\color{UVLType}\bfseries,      % Style for Group 5 (Types)
  commentstyle=\color{UVLComment}\itshape,       % Style for comments (Italic)
  stringstyle=\color{UVLString},                 % Style for strings
  % -- Environment Layout --
  backgroundcolor=\color{UVLBackground},         % Background color
  basicstyle=\uvlbasiccolor\ttfamily\scriptsize, % Base font family and size (script size)
  numbers=left,                  % Position of line numbers (left, right, or none)
  numberstyle=\tiny\color{gray}, % Style of line numbers
  stepnumber=1,                  % Interval of line numbers (1 = every line)
  numbersep=2pt,                 % Distance between line numbers and code
  tabsize=2,                     % Width of tab character (equivalent spaces)
  showstringspaces=false,        % Do not visualize spaces inside strings
  breaklines=true,               % Automatically wrap long lines
  extendedchars=true,            % Allow extended ASCII characters (utf8)
  upquote=true,                  % Force straight quotes (') instead of curly (’)
  frame=lines,                   % Draw a line above and below the snippet
  captionpos=t,                  % Caption position (b = bottom, t = top)
  rulecolor=\uvlbasiccolor,      % Color of the frame/border
  % -- Literate (Symbol & Number Replacement) --
  % Replaces specific characters with colored versions.
  literate={<=>}{{\textcolor{UVLOperator}{<=>}}}3
           {=>}{{\textcolor{UVLOperator}{=>}}}2
           {<=}{{\textcolor{UVLOperator}{<=}}}2
           {>=}{{\textcolor{UVLOperator}{>=}}}2
           {==}{{\textcolor{UVLOperator}{==}}}2
           {!=}{{\textcolor{UVLOperator}{!=}}}2
           {|}{{\textcolor{UVLOperator}{|}}}1
           {&}{{\textcolor{UVLOperator}{\&}}}1
           {!}{{\textcolor{UVLOperator}{!}}}1
           % Numbers (0-9)
           {0}{{\textcolor{UVLNumber}{0}}}1
           {1}{{\textcolor{UVLNumber}{1}}}1
           {2}{{\textcolor{UVLNumber}{2}}}1
           {3}{{\textcolor{UVLNumber}{3}}}1
           {4}{{\textcolor{UVLNumber}{4}}}1
           {5}{{\textcolor{UVLNumber}{5}}}1
           {6}{{\textcolor{UVLNumber}{6}}}1
           {7}{{\textcolor{UVLNumber}{7}}}1
           {8}{{\textcolor{UVLNumber}{8}}}1
           {9}{{\textcolor{UVLNumber}{9}}}1
           % Delimiters (Braces and Brackets)
           {\{}{{\textcolor{UVLDelimiter}{\{}}}1
           {\}}{{\textcolor{UVLDelimiter}{\}}}}1
           {[}{{\textcolor{UVLDelimiter}{[}}}1
           {]}{{\textcolor{UVLDelimiter}{]}}}1
           {(}{{\textcolor{UVLDelimiter}{(}}}1
           {)}{{\textcolor{UVLDelimiter}{)}}}1,
}

% --- 8. Public Interface ---

% Inheritance: UVL mimics UVLInternal.
% This allows us to rebuild UVL when adding user keywords without breaking styles.
\lstdefinelanguage{UVL}[]{UVLInternal}{}

% Command: \inputuvl
% Usage: \inputuvl[options]{filename.uvl}
% Description: Helper to import external UVL files.
\newcommand{\inputuvl}[2][]{%
    \lstinputlisting[language=UVL, #1]{#2}%
}

% Command: \uvlattributes
% Usage: \uvlattributes{Attr1, Attr2}
% Description: Adds custom keywords to Group 3 dynamically using inheritance.
\newcommand{\uvlattributes}[1]{%
    \lstdefinelanguage{UVL}[]{UVLInternal}{%
        morekeywords=[3]{#1}%
    }%
}

% --- Additional User Commands for Inline Use ---

% Command: \UVLKeyword
% Usage: \UVLKeyword{alternative}
% Description: Applies the UVL Keyword color and monospaced font.
\newcommand{\UVLKeyword}[1]{\textcolor{UVLKeyword}{\texttt{#1}}}

% Command: \feature
% Usage: \feature{Pizza}
% Description: Applies the UVL Feature color and monospaced font for feature names.
\newcommand{\feature}[1]{\textcolor{UVLFeature}{\texttt{#1}}}

% Command: \attribute
% Usage: \attribute{Price}
% Description: Applies the UVL Attribute color and monospaced font for attributes names.
\newcommand{\attribute}[1]{\textcolor{UVLAttribute}{\texttt{#1}}}

% Command: \constraint
% Usage: \constraint{Big => Mozzarella}
% Description: Applies the monospaced font for constraints.
\newcommand{\constraint}[1]{\texttt{#1}}

% Command: \UVL
% Usage: \UVL
% Description: Write the acronym using the same style as in the official paper.
\newcommand{\UVL}{\textsf{UVL}\xspace}

\endinput
%% End of file uvlhighlight.sty