renewcommand 中的 xstring 指令

Question

我正在嘗試\texttt以結束.或為條件更新命令,。但做了這個之後：

\usepackage{xstring}

\let\OldTexttt\texttt
\renewcommand{\texttt}[1]{%
    \OldTexttt{\hspace{0.4em}#1}%
    \IfEndWith{#1}{.}{}{\hspace{0.4em}}%    
}

編輯：不工作的例子。

\documentclass{article}

\usepackage{xstring}

\let\OldTexttt\texttt
\renewcommand{\texttt}[1]{%
    \OldTexttt{\hspace{0.4em}#1}%
    \IfEndWith{#1}{.}{}{\hspace{0.4em}}%
    \IfEndWith{#1}{,}{}{\hspace{0.4em}}%    
}


\begin{document}

\section{This is \texttt{section.}}
bbbb 
\texttt{test}
\texttt{section.}
\texttt{section,}
\texttt{test}
aaa

\end{document}

錯誤：

! Argument of \@sect has an extra }.
<inserted text> 
                \par 
l.18 \section{This is \texttt{section.}}

? 
! Emergency stop.
<inserted text> 
                \par 
l.18 \section{This is \texttt{section.}}

有人可以幫忙出什麼問題嗎？

Answer 1

這是一個嘗試的解決方案expl3

\documentclass[]{article}
\usepackage[T1]{fontenc}
\usepackage{beramono}
\usepackage{letltxmacro}

\LetLtxMacro\OldTexttt\texttt

\usepackage{xparse}
\ExplSyntaxOn
\cs_new:Npn \petr_extract_lasttoken:n #1
  {
   \tl_head:f { \tl_reverse:n { #1 } }
 }
\cs_generate_variant:Nn \tl_if_eq:nnF {xnF}

\DeclareDocumentCommand \texttt { m }
 {
  \hspace*{0.4cm}
  \OldTexttt{ #1 }
  \tl_if_eq:xnF  { \petr_extract_lasttoken:n {#1}  } { . } {\hspace*{0.4cm}}
 }
\ExplSyntaxOff
\begin{document}


foo \texttt{bar} foo

foo \texttt{bar.} foo

\section{This is \texttt{section.}}
bbbb 
\texttt{test}
\texttt{section.}
\texttt{section,}
\texttt{test}
aaa
\end{document}

Answer 2

重新定義的\texttt並不穩健。這可以透過使用\DeclareRobustCommand和使用letltxmacro負責 LaTeX 原始健壯內部結構的套件來完成\texttt：

\documentclass{article}

\usepackage{xstring}
\usepackage{letltxmacro}

\LetLtxMacro\OldTexttt\texttt
\DeclareRobustCommand*{\texttt}[1]{%
    \OldTexttt{\hspace{0.4em}#1}%
    \IfEndWith{#1}{.}{}{%
      \IfEndWith{#1}{,}{}{\hspace{0.4em}}%
    }%
}

\begin{document}

\section{This is \texttt{section.}}
bbbb
[\texttt{test}]
[\texttt{section.}]
[\texttt{section,}]
[\texttt{test}]
aaa

\end{document}

更新：此外，宏中的邏輯也被固定為獲取0.4em字串是否不以. 或者 ,。

Answer 3

這是一份工作l3regex！當然，人們仍然應該保存\texttt使用\LetLtxMacro.但是，我不會使用\hspace*：額外的空格應該會在換行符處消失。

\documentclass{article}
\usepackage[T1]{fontenc}

\usepackage{letltxmacro,xparse,l3regex}
\LetLtxMacro\latextexttt\texttt

\ExplSyntaxOn
\DeclareDocumentCommand \texttt { m }
 {
  \petr_spaced_texttt:n { #1 }
 }
\cs_new_protected:Npn \petr_spaced_texttt:n #1
 {
  \hspace{0.4em}
  \latextexttt{ #1 }
  % Check if the string ends with a period or a comma
  % \Z matches the end of the string
  \regex_match:nnF { (\.|\,) \Z } { #1 } { \hspace{0.4em} }
 }
\ExplSyntaxOff
\begin{document}
\tableofcontents

\section{This is |\texttt{section.}|}
bbbb 
|\texttt{test}|
|\texttt{section.}|
|\texttt{section,}|
|\texttt{test}|
aaa
\end{document}