answers.sty

%%
%% This is file `answers.sty',
%% generated with the docstrip utility.
%%
%% The original source files were:
%%
%% answers.dtx  (with options: `answers')
%% 
%% Originally developed by Mike Piff
%% Copyright (C) 1990,1994-1996 by Mike Piff
%% Copyright (C) 2009 by
%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
%% 
%% It may be distributed and/or modified under the conditions of
%% the LaTeX Project Public License (LPPL), either version 1.3c of
%% this license or (at your option) any later version.  The latest
%% version of this license is in the file:
%% 
%%    http://www.latex-project.org/lppl.txt
%% 
%% This work is "maintained" (as per LPPL maintenance status) by
%%   Joseph Wright.
%% 
\def\fileversion{2.13}
\def\filedate{11 Oct 2010 00:00:00 BST}
\def\filename{answers.dtx}
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{answers}
    [2010/10/11 v2.13 Production of solution sheets in LaTeX2e]
\newif\ifanswerfiles \answerfilestrue
\DeclareOption{nosolutionfiles}{\answerfilesfalse
   \typeout{No answer files being produced}}%
\ProcessOptions

\RequirePackage{verbatim}
\newcommand{\solutionpoint}{.}
\newcommand{\solutionextension}{tex}
\newenvironment{Filesave}[1]{%
   \@bsphack
   \def\verbatim@processline{}%
   \Iffileundefined{#1}{}{%
      \Ifopen{#1}{%
         \def\verbatim@processline{%
            \Ifanswerfiles{%
               \immediate\write\@nameuse{#1@file}%
                  {\the\verbatim@line}%
            }{}%
         }%
      }{}%
   }%
   \let\do\@makeother\dospecials
   \catcode`\^^M\active \catcode`\^^I=12\relax
   \verbatim@start
}{\@esphack}
\newcommand{\Writetofile}[2]{%
   \@bsphack
   \Iffileundefined{#1}{}{%
      \Ifopen{#1}{%
         {%
            \let\protect\string
            \Ifanswerfiles{%
               \immediate\write\@nameuse{#1@file}{#2}%
            }{}%
         }%
      }{}%
   }%
   \@esphack
}
\newcommand{\Ifopen}[3]{%
   \csname if#1open\endcsname#2\else#3\fi}%
\newcommand{\Iffileundefined}[3]{%
   \csname ifx\expandafter\endcsname
      \csname #1@file\endcsname\relax
      #2\else#3\fi}
\newcommand{\Ifanswerfiles}[2]{%
   \ifanswerfiles #1\else #2\fi}
\def\Opensolutionfile#1{%
   \@ifnextchar[{\define@filename{#1}}%
      {\define@filename{#1}[#1]}}%
\def\define@filename#1[#2]{%
   \global\@namedef{#1@filename}{#2\solutionpoint\solutionextension}%
   \Ifanswerfiles{%
      \typeout{Output from handle #1 going
         to #2.\solutionextension}%
   }{}%
   \Iffileundefined{#1}{%
      \expandafter\newwrite\csname #1@file\endcsname
      \csname newif\expandafter\endcsname
         \csname if#1open\endcsname
      \global\csname #1openfalse\endcsname
      \expandafter\ifx\csname Open#1hook\endcsname\relax
         \global\@namedef{Open#1hook}##1{}%
      \fi
      \expandafter\ifx\csname Close#1hook\endcsname\relax
         \global\@namedef{Close#1hook}##1{}%
      \fi
   }{}%
   \let\Tmp\relax
   \Ifopen{#1}{\typeout{File #1 already open}}{%
      \Ifanswerfiles{%
         \immediate\openout\@nameuse{#1@file}=%
         \@nameuse{#1@filename}%
      }{}%
      \global\csname#1opentrue\endcsname
      \def\Tmp{\@nameuse{Open#1hook}{#1}}%
   }%
   \Tmp
}
\def\Closesolutionfile#1{%
   \let\Tmp\relax
   \Iffileundefined{#1}{}{%
      \Ifopen{#1}{%
         \Ifanswerfiles{%
            \immediate\closeout\@nameuse{#1@file}%
         }{}%
         \global\csname #1openfalse\endcsname
         \def\Tmp{\@nameuse{Close#1hook}{#1}}%
      }{}%
   }%
   \Tmp
}
\def\Readsolutionfile#1{%
   \Ifanswerfiles{%
      \Iffileundefined{#1}{}{%
         \Ifopen{#1}{%
            \typeout{WARNING: attempt to read open file #1}%
         }{%
            \edef\Tmp{%
               \noexpand\InputIfFileExists
                  {\@nameuse{#1@filename}}{}%
               {\noexpand\message{File
                  \@nameuse{#1@filename}%
                     \space not found}}%
            }%
            \Tmp
         }%
      }%
   }{}%
}

\newcommand{\Newassociation}[3]{%
   \newsolution{#2}%
   \expandafter\ifx\csname #3opentrue\endcsname\relax
      \expandafter\newif\csname if#3open\endcsname
   \fi
   \newenvironment{#1}{%
      \Ifanswerfiles{%
         \let\Tmp\relax
         \Iffileundefined{#3}{}{%
            \Ifopen{#3}{%
               \immediate\write\@nameuse{#3@file}%
                  {\string\begin{#2}\@nameuse{#2params}}%
            \def\Tmp{\Filesave{#3}}%
            }{}%
         }%
      }{%
         \edef\Tmp{\noexpand\begin{#2}\@nameuse{#2params}}%
      }%
      \csname pre#1\endcsname
      \Tmp
   }%
   {%
      \Ifanswerfiles{%
         \Iffileundefined{#3}{}{%
            \Ifopen{#3}{%
               \endFilesave%
               \immediate\write\@nameuse{#3@file}%
                  {\string\end{#2}}%
               \csname post#1\endcsname
            }{}%
         }%
      }{%
         \end{#2}%
      }%
   }%
}
\newcommand{\newsolution}[1]{%
   \@ifundefined{#1}{%
      \global\@definecounter{#1}%
      \global\@namedef{#1params}{{\Currentlabel}}%
      \newenvironment{#1}[1]%
      {%
         \refstepcounter{#1}%
         \csname pre#1\endcsname
         \trivlist
         \item[\hskip\itemsep{\@nameuse{#1label}{##1}}]}%
      {\csname post#1\endcsname\endtrivlist}%
      \global\@namedef{#1label}##1{\solutionstyle{##1}}%
   }{\typeout{WARNING: environment #1 already in use}}%
}
\newcommand{\solutionstyle}[1]{\textbf{#1}}
\newcommand{\Currentlabel}{\@currentlabel}
\endinput
%%
%% End of file `answers.sty'.