\def\filedate{2003/12/03}
\def\fileversion{2.21}
%
% \iffalse
% File: nameref.dtx
% Copyright (C) 1995-9 Sebastian Rahtz
%               2000-3 Sebastian Rahtz, Heiko Oberdiek
%
%% This file is part of the `Hyperref Bundle'.
%% -------------------------------------------
%%
%% It may be distributed under the conditions of the LaTeX Project Public
%% License, either version 1.2 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 1.2 or later is part of all distributions of LaTeX
%% version 1999/12/01 or later.
%%
%% The list of all files belonging to the `Hyperref Bundle' is
%% given in the file `manifest.txt'.
%<*driver>
\documentclass{ltxdoc}
\begin{document}
  \title{%
    Section name references in \LaTeX
    \thanks{%
      This file has version number \fileversion,
      last revised \filedate.%
    }%
  }
  \author{Sebastian Rahtz}
  \date{\filedate}
  \maketitle
  \tableofcontents
  \DocInput{nameref.dtx}
\end{document}
%</driver>
% \fi
% \CheckSum{463}
% \StopEventually{}
% \section{Introduction}
% Cross-referencing to include the \emph{name} of the section, rather than
% just the number or page. This works by redefining some of the inside
% \LaTeX\ macros, so it is vulnerable to future changes.
% \section{History}
% Sebastian Rahtz, for Lou Burnard, March 15th 1994;
% SPQR CERN July 1994;
% Last mod. Sept. 3th MG;
% Sept. 19th SPQR;
% April 11th 1995 SPQR (added section formatting hook);
% April 14th 1995 SPQR (compatibility with hyperref);
% June 22 1995 SPQR (removed typeout from Sectionformat);
% September 22 1997 added varioref hacks by Corey Minyard;
% September 28th changes by David Carlisle.
%    \begin{macrocode}
%<*package>
\ProvidesPackage{nameref}[\filedate\space v\fileversion
  \space Cross-referencing by name of section]
%    \end{macrocode}
%
% We redefine |\label| so that it also writes the name of the
% current section to the .aux file; if the name ends in a dot,
% we zap it. To allow for the hyperref package, also write
% fourth and fifth fields (empty by default;
% used for cross-ref name, and file).
%    \begin{macrocode}
\def\strip@period#1.\relax#2\@@@{#1}
%    \end{macrocode}
%
%    Here is tested, whether package showkeys is loaded.
%    But if option final is used, the macros of showkeys
%    are not defined, so we have to check an additional
%    test.
%    \begin{macrocode}
\newif\ifNR@showkeys
\NR@showkeysfalse
\@ifpackageloaded{showkeys}{%
  \begingroup
    \@ifundefined{SK@@label}{%
    }{%
      \global\NR@showkeystrue
    }%
  \endgroup
}{}
%    \end{macrocode}
%    \begin{macrocode}
\def\label#1{%
  \@bsphack
  \begingroup
    \let\label\@gobble
    \def\ref{\protect\ref}%
    \edef\@currentlabstr{%
      \expandafter\strip@prefix\meaning\@currentlabelname
    }%
    \protected@write\@auxout{}{%
      \string\newlabel{#1}{%
        {\@currentlabel}%
        {\thepage}%
        {\expandafter\strip@period\@currentlabstr\relax.\relax\@@@}%
        {\@currentHref}{}%
      }%
    }%
  \endgroup
  \@esphack
}%
\ifNR@showkeys
  \def\label#1{%
    \@bsphack
    \SK@\SK@@label{#1}%
    \begingroup
      \let\label\@gobble
      \def\ref{\protect\ref}%
      \edef\@currentlabstr{%
        \expandafter\strip@prefix\meaning\@currentlabelname
      }%
      \protected@write\@auxout{}{%
        \string\newlabel{#1}{%
          {\@currentlabel}%
          {\thepage}%
          {\expandafter\strip@period\@currentlabstr\relax.\relax\@@@}%
          {\@currentHref}{}%
        }%
      }%
    \endgroup
    \@esphack
  }%
\fi
%    \end{macrocode}
%    \begin{macrocode}
\let\ltx@label\label
%    \end{macrocode}
% Needed for the \emph{subeqnarray} package.
%    \begin{macrocode}
\@ifundefined{slabel}{}{%
  \def\slabel#1{%
    \@bsphack
    \if@filesw
      {%
        \let\label\@gobble
        \def\ref{\protect\ref}%
        \edef\@currentlabstr{%
          \expandafter\strip@prefix\meaning\@currentlabelname
        }%
        \let\thepage\relax
        \def\protect{\noexpand\noexpand\noexpand}%
        \edef\@tempa{%
          \write\@auxout{%
            \string\newlabel{#1}{%
              {\thesubequation}%
              {\thepage}%
              {\expandafter\strip@period
                \@currentlabstr\relax.\relax\@@@}%
              {\@currentHref}{}%
            }%
          }%
        }%
        \expandafter
      }%
      \@tempa
      \if@nobreak\ifvmode\nobreak\fi\fi
    \fi
    \@esphack
  }%
}
%    \end{macrocode}
% Overload an AMS \LaTeX\ command, which uses |\newlabel|. Sigh!
%    \begin{macrocode}
\def\@writetocindents@{%
  \begingroup
  \@for\@tempa:=-1,0,1,2,3\do{%
    \immediate\write\@auxout{%
      \string\newlabel{tocindent\@tempa}{%
        \csname r@tocindent\@tempa\endcsname{}{}{}{}%
      }%
    }%
  }%
  \endgroup}
%    \end{macrocode}
% Add to the underlying section heading macros so that they
% note the section name for use by label.
%
% If a section heading or the like has a |\label| in it,
% we need to extract it, or subsequent processing breaks.
% This is done by the label-writing routine.
%
% First the numbered sections. While we are about it, put in
% a useful section formatting macro.
%    \begin{macrocode}
\let\NR@sect\@sect
\newcounter{section@level}
\def\@sect#1#2#3#4#5#6[#7]#8{%
  \setcounter{section@level}{#2}%
  \def\@currentlabelname{#7}%
  \NR@sect{#1}{#2}{#3}{#4}{#5}{#6}[{#7}]{\Sectionformat{#8}{#2}}%
}
%    \end{macrocode}
% and now the unnumbered ones
%    \begin{macrocode}
\let\NR@ssect\@ssect
\def\@ssect#1#2#3#4#5{%
  \def\@currentlabelname{#5}%
  \NR@ssect{#1}{#2}{#3}{#4}{\Sectionformat{#5}{#1}}%
}
%    \end{macrocode}
%
% Parts and chapters are treated differently. sigh.
%
%    \begin{macrocode}
\let\NR@part\@part
\def\@part[#1]#2{%
  \def\@currentlabelname{#1}%
  \NR@part[{#1}]{#2}%
}
\let\NR@chapter\@chapter
\def\@chapter[#1]#2{%
  \def\@currentlabelname{#1}%
  \NR@chapter[{#1}]{#2}%
}
\let\NR@schapter\@schapter
\def\@schapter#1{%
  \def\@currentlabelname{#1}%
  \NR@schapter{#1}%
}
%    \end{macrocode}
%
% Compatibility for package titlesec.
%    \begin{macrocode}
\AtBeginDocument{%
  \@ifpackageloaded{titlesec}{%
    \let\NRorg@ttl@sect@i\ttl@sect@i
    \def\ttl@sect@i#1#2[#3]#4{%
      \def\@currentlabelname{#4}%
      \NRorg@ttl@sect@i{#1}{#2}[{#3}]{#4}%
    }%
  }{}%
}
%    \end{macrocode}
%
% We default the label and hypertext reference to be empty.
%    \begin{macrocode}
\def\@currentlabelname{}
\def\@currentHref{}
%    \end{macrocode}
% Since the second part of the preserved reference now has five parts
% (number, page, name, hypertext reference and file), we need extra utility
% macros:
%    \begin{macrocode}
\long\def\@firstoffive#1#2#3#4#5{#1}
\long\def\@secondoffive#1#2#3#4#5{#2}
\long\def\@thirdoffive#1#2#3#4#5{#3}
\long\def\@fourthoffive#1#2#3#4#5{#4}
\long\def\@fifthoffive#1#2#3#4#5{#5}
%    \end{macrocode}
% We have to redefine |\ref| and |\pageref| to know about extra
% reference elements. Make them robust, and compatible with Babel.
% The Babel switch is mimicked if not already defined.
% Some support for package |showkeys| is implemented. If
% option |notref| of that package is set, |\SK@ref| has the
% meaning of |\@empty|.
%    \begin{macrocode}
\providecommand*\@safe@activestrue{}%
\providecommand*\@safe@activesfalse{}%
\def\T@ref#1{%
  \@safe@activestrue
  \expandafter\@setref\csname r@#1\endcsname\@firstoffive{#1}%
  \@safe@activesfalse
}%
\def\T@pageref#1{%
  \@safe@activestrue
  \expandafter\@setref\csname r@#1\endcsname\@secondoffive{#1}%
  \@safe@activesfalse
}%
\ifNR@showkeys
  \ifx\SK@ref\@empty
  \else
    \def\T@ref#1{%
      \@safe@activestrue
      \SK@\SK@@ref{#1}%
      \expandafter\@setref\csname r@#1\endcsname\@firstoffive{#1}%
      \@safe@activesfalse
    }%
    \def\T@pageref#1{%
      \@safe@activestrue
      \SK@\SK@@ref{#1}%
      \expandafter\@setref\csname r@#1\endcsname\@secondoffive{#1}%
      \@safe@activesfalse
    }%
  \fi
\fi
%    \end{macrocode}
%    Package |hyperref| uses its own definitions of |\ref| and
%    |\pageref| because it extends the syntax by the star form.
%    |\DeclareRobustCommand| is used by hyperref.
%    Package |nameref| can be loaded before, after hyperref or after
%    hyperref's definitions in |\AtBeginDocument|.
%    \begin{macrocode}
\@ifpackageloaded{hyperref}{%
}{%
  \DeclareRobustCommand{\ref}{\T@ref}%
  \DeclareRobustCommand{\pageref}{\T@pageref}%
}
%    \end{macrocode}
% \section{Usage and frontend}
% Access the (third) name part with |\nameref|;
%    \begin{macrocode}
\def\T@nameref#1{%
  \@safe@activestrue
  \expandafter\@setref\csname r@#1\endcsname\@thirdoffive{#1}%
  \@safe@activesfalse
}%
\ifNR@showkeys
  \ifx\SK@ref\@empty
  \else
    \def\T@nameref#1{%
      \@safe@activestrue
      \SK@\SK@@ref{#1}%
      \expandafter\@setref\csname r@#1\endcsname\@thirdoffive{#1}%
      \@safe@activesfalse
    }%
  \fi
\fi
\def\nameref{\protect\T@nameref}
%    \end{macrocode}
% An extended form which gives title and page number.
%    \begin{macrocode}
\def\Nameref#1{`\nameref{#1}' on page~\pageref{#1}}
%    \end{macrocode}
%
% The default for |\Sectionformat|
%    \begin{macrocode}
\providecommand\Sectionformat[2]{#1}
%    \end{macrocode}
% \subsection{Compatibility with varioref}
% [This section was derived by Corey Minyard \texttt{minyard@acm.org}
% from the varioref package]
%    \begin{macrocode}
\ifx\csname @@vpageref\endcsname\relax
\else
  \def\@@vpageref#1[#2]#3{%
    \leavevmode\unskip
    \global\advance\c@vrcnt\@ne
    \@ifundefined{r@\the\c@vrcnt @vr}%
      {\@namedef{r@\the\c@vrcnt @vr}{{??}{??}{??}{??}{??}}}{}%
    \edef\@tempa{%
      \expandafter\expandafter\expandafter
      \@secondoffive\csname r@\the\c@vrcnt @vr\endcsname
    }%
    \@ifundefined{r@\the\c@vrcnt @xvr}%
      {\@namedef{r@\the\c@vrcnt @xvr}{{??}{??}{??}{??}{??}}}{}%
    \edef\@tempb{%
      \expandafter\expandafter\expandafter
      \@secondoffive\csname r@\the\c@vrcnt @xvr\endcsname
    }%
    {%
      \let\@currentlabel\@empty
      \expandafter\label\expandafter{\the\c@vrcnt @xvr}%
    }%
    \ifx\@tempa\@tempb
    \else
      \vref@err{%
        \noexpand\vref at page boundary
        \@tempb-\@tempa\space (may loop)%
      }%
    \fi
    \@ifundefined{r@#3}{\@namedef{r@#3}{{??}{??}{??}{??}{??}}}{}%
    \edef\@tempb{%
      \expandafter\expandafter\expandafter
      \@secondoffive\csname r@#3\endcsname
    }%
    \space
    \ifx\@tempa\@tempb
      #1%
    \else
      #2%
      \is@pos@number\@tempb{%
        \is@pos@number\@tempa{%
          \@tempcnta\@tempa
          \advance\@tempcnta\@ne
        }{%
          \@tempcnta\maxdimen
        }%
        \ifnum \@tempb =\@tempcnta
          \ifodd\@tempcnta
            \if@twoside
              \reftextfaceafter
            \else
              \reftextafter
            \fi
          \else
            \reftextafter
          \fi
        \else
          \advance\@tempcnta-2
          \ifnum \@tempb =\@tempcnta
            \ifodd\@tempcnta
              \reftextbefore
            \else
              \if@twoside
                \reftextfacebefore
              \else
                \reftextbefore
              \fi
            \fi
          \else
            \reftextfaraway{#3}%
          \fi
        \fi
      }{%
        \reftextfaraway{#3}%
      }%
    \fi
    {%
      \let\@currentlabel\@empty
      \expandafter\label\expandafter{\the\c@vrcnt @vr}%
    }%
  }%
  \DeclareRobustCommand\vnameref[1]{%
    \unskip~\nameref{#1}%
    \@vpageref[\unskip]{#1}%
  }
\fi
%</package>
%    \end{macrocode}
%
% \Finale
\endinput