后提问关于如何从头开始实现特定的基本索引，我使用我找到的解决方案创建了一个 LaTeX 包（hereapplies.sty）。
使用方法非常简单。例如，
\documentclass{article}
\usepackage{hereapplies}
\begin{document}
\title{Some title}
\author{Some author}
\maketitle
This is concept one. To see this concept applied, please
see\whereapplies{conceptone}.
This is concept four. To see this concept applied, please
see\whereapplies{conceptfour}.\newpage
\hereapplies{conceptone}This is page \thepage. As you can see, ``concept
one'' applies here.\newpage
\hereapplies{conceptfour}This is page \thepage. As you can see,
``concept four'' applies here.\newpage
\hereapplies{conceptone}This is page \thepage. As you can see, ``concept
one'' applies here.\newpage
\hereapplies{conceptfour}This is page \thepage. As you can see,
``concept four'' applies here.\newpage
\hereapplies{conceptone}This is page \thepage. As you can see, ``concept
one'' applies here.
\end{document}
生成以下输出：
但是还有一个 bug，如果你仔细看，你会发现稿件文本中please see\whereapplies{conceptone}的“see”后面没有空格，但 pdf 中却加了一个空格。如果我尝试在稿件中添加一个空格（如please see \whereapplies{conceptone}），结果会包含两个空格，如下图所示：
我怎样才能去掉那个不需要的双倍空格？如果我不在手稿中添加空格，我希望输出中也不包含空格。
为了完整起见，我在这里粘贴我的包的当前状态：
% -*- Mode: latex; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*-
%
% hereapplies.sty
%
% A LaTeX package for cross-linking applications of concepts
%
% https://github.com/madmurphy/hereapplies.sty
%
% Version 0.2.0a
%
% Copyright (C) 2022 madmurphy <[email protected]>
%
% **Here Applies** is free software: you can redistribute it and/or modify it
% under the terms of the GNU Affero General Public License as published by the
% Free Software Foundation, either version 3 of the License, or (at your
% option) any later version.
%
% **Here Applies** is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
% FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
% for more details.
%
% You should have received a copy of the GNU Affero General Public License
% along with this program. If not, see <http://www.gnu.org/licenses/>.
%
%
%
% Example usage:
%
% \documentclass{article}
%
% \usepackage{hereapplies}
%
% \begin{document}
%
% \title{Some title}
%
% \author{Some author}
%
% \maketitle
%
% This is concept one. To see this concept applied, please
% see\whereapplies{conceptone}.
%
% This is concept four. To see this concept applied, please
% see\whereapplies{conceptfour}.\newpage
%
% \hereapplies{conceptone}This is page \thepage. As you can see, ``concept
% one'' applies here.\newpage
%
% \hereapplies{conceptfour}This is page \thepage. As you can see,
% ``concept four'' applies here.\newpage
%
% \hereapplies{conceptone}This is page \thepage. As you can see, ``concept
% one'' applies here.\newpage
%
% \hereapplies{conceptfour}This is page \thepage. As you can see,
% ``concept four'' applies here.\newpage
%
% \hereapplies{conceptone}This is page \thepage. As you can see, ``concept
% one'' applies here.
%
% \end{document}
%
%
\ProvidesPackage{hereapplies}
\RequirePackage{hyperref}
%
%
%
% PRIVATE ENVIRONMENT
% ===================
%
%
% Assign a unique number to each applicable concept
\newcounter{@ha@concept@counter}
%
%
% Macro `\@ha@newapplicable{concept_name}`
% *****************************************************************************
%
% Initialize a new applicable concept
%
% Thie macro is for internal purposes only. When invoked it sets up the helper
% macros, counters and auxiliary files needed for keeping track of a concept.
% If the concept was already initialized this macro will be no op.
%
\newcommand{\@ha@newapplicable}[1]{%
% Was this concept already initialized?
\expandafter\ifx\csname @ha@concept@#1@cursor\endcsname\relax%
% The concept was never initialized
% Move the counter to the current id
\stepcounter{@ha@concept@counter}%
% Count unnamed occurrences
\newcounter{@ha@concept@#1@unnamed@counter}%
% Saved in .haN file
\expandafter\def\csname @ha@concept@#1@output\endcsname{\textbf{??}}%
% Last page that applies
\expandafter\def\csname @ha@concept@#1@cursor\endcsname{-1}%
% Store the id of the current concept
\expandafter\edef\csname @ha@concept@#1@id\endcsname{\arabic{@ha@concept@counter}}%
% Executes stuff in .haN file
\@starttoc{ha\csname @ha@concept@#1@id\endcsname}%
% Store all the occurrences when the document ends
\AtEndDocument{%
% Set the .haN file as the output
\addtocontents{ha\csname @ha@concept@#1@id\endcsname}{%
% Check that there are occurrences
\expandafter\ifcsname @ha@concept@#1@cache\endcsname%
% There are occurrences - write "p./pp. ..." to the output
\gdef\expandafter\protect\csname @ha@concept@#1@output\endcsname{%
\csname @ha@concept@#1@preamble\endcsname\csname @ha@concept@#1@cache\endcsname%
}%
\else%
% There are no occurrences - write "??" to the output
\gdef\expandafter\protect\csname @ha@concept@#1@output\endcsname{%
\textbf{??}%
}%
\fi%
}%
}%
\fi%
}
%
%
% Macro: `\starred@hereapplies[occurrence_name]{concept_name}`
% *****************************************************************************
%
% Equivalent to `\hereapplies*`
%
% Thie macro is for internal purposes (but nothing forbids invoking it
% directly).
%
\newcommand{\starred@hereapplies}[2][]{%
% Make sure that the concept has been initialized
\@ha@newapplicable{#2}%
\ifx&%
% The macro has been called with only one argument
% Assign a unique number to the unnamed occurrence
\stepcounter{@ha@concept@#2@unnamed@counter}%
% Call `\starred@hereapplies` again (recursion), but this time with 2 arguments
\edef\tmp{\noexpand\starred@hereapplies[__unnamed\arabic{@ha@concept@#2@unnamed@counter}__]{#2}}\tmp%
\else%
% The macro has been called with two arguments
% Assign a label to this occurrence
\label{appl:#2:#1}%
% If the cursor already points to the current page do nothing
\unless\ifnum\csname @ha@concept@#2@cursor\endcsname=\thepage%
% Make the cursor point to the current page
\expandafter\edef\csname @ha@concept@#2@cursor\endcsname{\thepage}%
% Is this the first occurrence?
\expandafter\ifcsname @ha@concept@#2@cache\endcsname%
% This is *not* the first occurrence
% Use "pp." for the preamble when there are multiple occurrences
\expandafter\def\csname @ha@concept@#2@preamble\endcsname{pp.~}%
% Populate the cache
\expandafter\g@addto@macro\csname @ha@concept@#2@cache\endcsname{, \pageref{appl:#2:#1}}%
\else%
% This is the first occurrence
% Use "p." for the preamble when there is only one occurrence
\expandafter\def\csname @ha@concept@#2@preamble\endcsname{p.~}%
% Initialize the cache
\expandafter\def\csname @ha@concept@#2@cache\endcsname{\pageref{appl:#2:#1}}%
\fi%
\fi%
\fi%
}
%
%
%
% PUBLIC ENVIRONMENT
% ===================
%
%
% Macro: `\hereapplies[occurrence_name]{concept_name}`
% *****************************************************************************
%
% Notify the document that here a particular concept applies
%
% If the `occurrence_name` argument is passed, a new label will be created in
% the form `appl:[concept_name]:[occurrence_name]`. Without this argument the
% label created will have an opaque name.
%
% The starred version of this macro (`\hereapplies*`) will not invoke the
% `\phantomsection` directive before generating the label.
%
\newcommand{\hereapplies}{%
% Check if a star is present
\@ifstar{\starred@hereapplies}{\phantomsection\relax\starred@hereapplies}%
}
%
%
% Macro: `\whereapplies{concept_name}`
% *****************************************************************************
%
% Print all the applications of a concept in the form "p./pp. ..."
%
\newcommand{\whereapplies}[1]{%
% Make sure that the applicable concept is initialized
\@ha@newapplicable{#1}%
% Print all the applications of the concept
\csname @ha@concept@#1@output\endcsname%
}
答案1
你做的\@starttoc{ha\csname @ha@concept@#1@id\endcsname}，以及\@starttoc其他事情做的\@input{\jobname.#1}
很难避免\input至少在文件末尾的行尾生成空格标记，但是在文件末尾有额外的空格，}例如
\gdef \@ha@concept@conceptfour@output {pp.\nobreakspace {}\pageref {appl:concept
four:__unnamed1__}, \pageref {appl:conceptfour:__unnamed2__}}
因为看起来你使用了全局定义，所以你可以使用
{\endlinechar=\m@ne\@starttoc{ha\csname @ha@concept@#1@id\endcsname}}%
在第 104 行，以便在读取文件时忽略行尾。