为了能够通过添加新部分来概述我的文档的大部分内容，但又不使编译后的文档中出现我未写任何内容的部分，我基于来自的宏定义了五个宏当部分为空时隐藏部分标题：
\newcommand{\showpart}[2]{%
\ifstrequal{ #2}{ }{}{\part{#1} #2}%
}
\newcommand{\showchapter}[2]{%
\ifstrequal{ #2}{ }{}{\chapter{#1} #2}%
}
\newcommand{\showsection}[2]{%
\ifstrequal{ #2}{ }{}{\section{#1} #2}%
}
\newcommand{\showsubsection}[2]{%
\ifstrequal{ #2}{ }{}{\subsection{#1} #2}%
}
\newcommand{\showsubsubsection}[2]{%
\ifstrequal{ #2}{ }{}{\subsubsection{#1} #2}%
}
现在我在整个源文件中都使用它们，而不是正常的、、\part和。我还添加了序言以获取宏。但是，我尚未开始编写任何内容的所有部分仍然显示在编译后的文档中。我做错了什么？\chapter\section\subsection\subsubsection\usepackage{etoolbox}ifstrequal
答案1
您似乎遇到的问题是\showxxxx宏的第二个参数中有空行。这些空行会导致段落中断，即\par添加了一个。这意味着您必须测试三种不同的东西：参数完全为空、参数为空格、参数为空格加\par。您可以使用以下代码执行此操作：
\documentclass{article}
\makeatletter
\newcommand{\showsection}[2]{%
\begingroup
\def\@tempa{#2}%
\def\@tempb{ \par}%
\ifcase0%
\ifx\@tempa\@empty 1\else
\ifx\@tempa\space 1\else
\ifx\@tempa\@tempb 1\fi\fi\fi
\relax
\endgroup
\section{#1} #2%
\else
\endgroup
\fi
}
\makeatother
\begin{document}
\showsection{test1}{
Some text
}
\showsection{test2}{}
\showsection{test3}{
}
\showsection{test4}{
}
\end{document}
如果您需要将其用于多个不同的分段命令，我会将其转变为通用宏，而不是为每个命令复制代码。
\makeatletter
\newcommand{\showsectioning}[3]{%
\begingroup
\def\@tempa{#3}%
\def\@tempb{ \par}%
\ifcase0%
\ifx\@tempa\@empty 1\else
\ifx\@tempa\space 1\else
\ifx\@tempa\@tempb 1\fi\fi\fi
\relax
\endgroup
#1{#2} #3%
\else
\endgroup
\fi
}
\makeatother
\newcommand\showsection{\showsectioning\section}
\newcommand\showsubsection{\showsectioning\subsection}
\newcommand\showsubsubsection{\showsectioning\subsubsection}
\newcommand\showchapter{\showsectioning\chapter}
\newcommand\showpart{\showsectioning\part}
替代更好的解决方案
由于您还想忽略较高的分段命令，而只使用空的较低分段命令，因此上述解决方案并不合理。（如果您发布了正常使用示例，那就更好了。）您必须检查很多组合。我建议采用不同的方法。您可以让宏\show...向前查看并检查是否还有\par其他宏以外的内容，而不是将整个（子..）部分作为宏参数读取，这无论如何都非常低效\show...。如果此宏是较低的分段宏，请使用缓冲区记住当前宏，并在找到某些内容或较高宏时重复此操作\show...。在 TeX 的强大功能范围内编写类似的东西，但是一个高级主题。
这里是我建议的解决方案包括示例/测试代码：
\documentclass{article}
\newcommand{\showpart}{%
\showsectioning{1}\part
}
\newcommand{\showchapter}{%
\showsectioning{2}\chapter
}
\newcommand{\showsection}{%
\showsectioning{3}\section
}
\newcommand{\showsubsection}{%
\showsectioning{4}\subsection
}
\newcommand{\showsubsubsection}{%
\showsectioning{5}\subsubsection
}
\makeatletter
\expandafter\let\csname showsectioning@buffer@1\endcsname\@empty
\expandafter\let\csname showsectioning@buffer@2\endcsname\@empty
\expandafter\let\csname showsectioning@buffer@3\endcsname\@empty
\expandafter\let\csname showsectioning@buffer@4\endcsname\@empty
\expandafter\let\csname showsectioning@buffer@5\endcsname\@empty
\chardef\showsectioning@highestlevel=0\relax
\newcommand{\showsectioning}[3]{%
\@ifnextchar\par{%
\@firstoftwo{\showsectioning{#1}{#2}{#3}}%
}{%
\@showsectioning{#1}{#2}{#3}%
}%
}
% Own macro for efficiency
% The next token is in \@let@token
\newcommand{\@showsectioning}[3]{%
% Store highest level
\ifnum\showsectioning@highestlevel=0
\chardef\showsectioning@highestlevel=#1\relax
\fi
% Store number of next sectioning macro (0 = no sectioning macro)
\chardef\showsectioning@number=0%
\ifx\@let@token\showpart 1\else
\ifx\@let@token\showchapter 2\else
\ifx\@let@token\showsection 3\else
\ifx\@let@token\showsubsection 4\else
\ifx\@let@token\showsubsubsection 5\fi
\fi\fi\fi\fi\relax
\ifcase0%
\ifnum#1<\showsectioning@number 1\else
\ifnum\showsectioning@number>\showsectioning@highestlevel 2\else
\ifnum\showsectioning@number>0 3\else
\ifx\@let@token\end 3\fi
\fi\fi\fi
\relax% case 0
% Some content found
% Pasting and clearing all buffers
\@tempcnta=\showsectioning@highestlevel
\loop
\csname showsectioning@buffer@\number\@tempcnta\endcsname
\global\expandafter\let\csname showsectioning@buffer@\number\@tempcnta\endcsname\@empty
\advance\@tempcnta\@ne
\ifnum\@tempcnta<6
\repeat
#2{#3}%
\or% case 1
% Lower sectioning command found, buffering current level
\global\@namedef{showsectioning@buffer@#1}{#2{#3}}%
\or% case 2
% Higher sectioning command found, but still a lower one than the highest level
% Clearing all buffers up to this level
\@tempcnta=\showsectioning@number
\loop
\global\expandafter\let\csname showsectioning@buffer@\number\@tempcnta\endcsname\@empty
\advance\@tempcnta\@ne
\ifnum\@tempcnta<6
\repeat
\else% case 3
% Some end delimiter found (\end, \show... command of higher level)
% Therefore no content, clearing all buffers
\@tempcnta=\showsectioning@highestlevel
\loop
\global\expandafter\let\csname showsectioning@buffer@\number\@tempcnta\endcsname\@empty
\advance\@tempcnta\@ne
\ifnum\@tempcnta<6
\repeat
\fi
}
\makeatother
\begin{document}
\showsection{Not empty}
test
\showsection{empty}
\showsection{Not empty again}
Hello
\showsection{With empty subsection}
\showsubsection{empty subsection}
\showsection{With non empty subsection}
\showsubsection{Non empty subsection}
Not empty
\showsection{With empty subsection and empty subsubsection}
\showsubsection{empty subsection}
\showsubsubsection{empty subsubsection}
\showsection{Not empty, but with empty subsection}
Stuff
\showsubsection{empty subsection}
\showsection{With \texttt{\string\empty}}
\empty
\showsection{With \texttt{\string\relax}}
\relax
\showsection{Multiple levels 1}
\showsubsection{Multiple levels 1a}
\showsubsection{Multiple levels 1b}
\showsubsubsection{Multiple levels 1bI}
\showsubsubsection{Multiple levels 1bII}
\showsubsection{Multiple levels 1c}
test
\showsection{trailing}
\end{document}