% tagging.sty
% Copyright 2011 Brent Longborough
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3 or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% This work has the LPPL maintenance status `maintained'.
% The Current Maintainer of this work is Brent Longborough.
%
% This work consists of these files: 
%     tagging.sty, tagging.tex, and tagging.pdf
% --------------------------------------------------------------
\ProvidesPackage{tagging}[2011/08/04]
\RequirePackage{etoolbox,verbatim}
\newcommand{\taggedy}{\relax}
\newcommand{\taggedn}{\relax}
\newcommand\usetag[1]{%
  \def\do##1{\csdef{tagged@##1}{}}%
  \docsvlist{#1}}%
\newcommand\droptag[1]{%
  \def\do##1{\csundef{tagged@##1}{}}%
  \docsvlist{#1}}%
\newenvironment{taggedblock}[1]%
    {\def\do##1{%
        \ifcsname tagged@##1\endcsname%
        \let\comment\relax%
        \let\endcomment\relax%
    \fi}%
    \docsvlist{#1}%
    \comment}%
    {\endcomment\leavevmode}%
\newenvironment{untaggedblock}[1]{%
    \csdef{@tagged@flag}{}
    \def\do##1{%
        \ifcsname tagged@##1\endcsname%
            \csundef{@tagged@flag}{}
        \fi}%
    \docsvlist{#1}%
    \ifcsname @tagged@flag\endcsname%
        \let\comment\relax%
        \let\endcomment\relax%
    \fi%
    \comment}%
    {\endcomment\leavevmode}%
\newcommand{\iftagged}[3]%
  {\renewcommand{\taggedy}{#2}%
   \renewcommand{\taggedn}{#3}%
   \def\do##1{%
     \ifcsdef{tagged@##1}{\renewcommand{\taggedn}{\taggedy}}{}}%
   \docsvlist{#1}%
   \taggedn%
  }%
\newcommand{\tagged}[2]{\iftagged{#1}{#2}{}}
\newcommand{\untagged}[2]{\iftagged{#1}{}{#2}}
