% INDEX PSIZZL - indexing macros for TeX version 1.0
% index entries come in two visibilities - non-silent and silent
% non-silent entries are preceeded by a ^
% while silent entries are preceeded by ^^
% the four types of non-silent entries are as follows
% ^{text}   - type 0, normal
% ^|text|   - type 1, TeX input, but not a control sequence
% ^|\text|  - type 2, TeX control sequence
% ^\<text>  - type 3, TeX concept, a mnemonic name
% the format of the entry in the index file is:
% text_!n_pp.  where _ is a space, n is the index type,
%                    pp is the page number
\newif\ifproofindex
\let\numbercount=\relax
\def\\{%
   {\tt\char'134}%
   }%
\def\<{%
   \relax\ifmmode\mskip\medmuskip\else\char'74\fi
   }%
\newwrite\@ndexwrite\def\@ndexfile{index.psiztemp }%
\adddef\fmtreset{%
   \immediate\openout\@ndexwrite=\@ndexfile % file for index reminders
   }%
\newif\ifsilent
\def\specialhat{%
   \relax\ifmmode\def\next{^}\else\let\next=\beginxref\fi\next
   }%
\def\beginxref{%
   \futurelet\next\beginxrefswitch
   }%
\def\beginxrefswitch{%
   \ifx\next\specialhat\let\next\silentxref
      \else\silentfalse\let\next\xref
      \fi
   \next
   }%
{\c@tCactive\global\let^\specialhat\gdef\silentxref^{\silenttrue\xref}}%
\c@tCactive\adddef\l@twrite\l@tCzero %this turns on indexing capability
{\c@tVcontrol\c@tBactive|gdef\{}}% \ as an active character -> nothing
\def\marginstyle{\vrule height6pt depth2pt width0pt \sevenrm}%
\chardef\bslash=`\\
\def\xref{%
   \futurelet\next\xrefswitch
   }%
\def\xrefswitch{%
   \begingroup
      \ifx\next|%
         \aftergroup\vxref % case 1 or 2, |arg| or |\arg|
         \else
         \ifx\next\<%
            \aftergroup\anglexref % case 3, "\<arg>" means angle bracke
            \else
            \aftergroup\normalxref% case 0, "{arg}"
            \fi
         \fi
      \endgroup
   }%
\def\vxref|{\c@tBactive\futurelet\next\vxrefswitch}%
\def\vxrefswitch#1|{\c@tBcontrol
   \ifx\next\empty
      \def\xreftype{2}\def\next{{\tt\bslash\text}}% type 2, |\arg|
      \else
      \def\xreftype{1}\def\next{{\tt\text}}% type 1, |arg|
      \fi
   \edef\text{#1}\makexref
   }%
\def\anglexref\<#1>{%
   \def\xreftype{3}\def\text{#1}\def\next{$\langle$\text$\rangle$}%
   \makexref
   }%
\def\normalxref#1{%
   \def\xreftype{0}\def\text{#1}\let\next=\text\makexref
   }%
\def\makexref{%
   \ifproofindex
      \insert\margin{\hbox{\marginstyle\text}}%
      \xdef\writeit{%
         \write\@ndexwrite{%
            \text\space!\xreftype\space\noexpand\number\p@gecount.%
            }%
         }%
      \writeit
      \else\ifhmode\kern\z@\fi
      \fi
   \ifsilent\ignorespaces\else\next\fi
   }%
% the \insert (which is done in proofmode only) suppresses hyphenation,
% so the \kern\z@ is put in to give the same effect in non-proofmode.