宏扩展奇怪地崩溃

Question

这是我的 mwe.tex

\documentclass[12pt]{report}
\usepackage{xifthen}
\usepackage{xstring}

\def\test{\textnormal{test}}

\newcounter{wordCount}
\setcounter{wordCount}{0}
\newcounter{AllWord}
\setcounter{AllWord}{0}

\NewDocumentCommand{\exy}{ m m m}{%
    \StrCount{#2}{,}[\comma]
    \StrCount{#2}{?}[\qmark]
    \ifthenelse{\qmark > 0}{%
        \addtocounter{wordCount}{\comma + \qmark}
        \addtocounter{AllWord}{\comma + \qmark}
    }{%
        \addtocounter{wordCount}{\comma + \qmark + 1}
        \addtocounter{AllWord}{\comma + \qmark + 1}
    }
    \textbf{#2} (#3), ``#1''\\%
}

\begin{document}
    \test\par
    \exy{one \test}{two \test s}{three \test s}
\end{document}

如果你注释掉该行，\exy它会按预期工作。否则错误以

[{
    "resource": "/c:/Users/hsmye/LaTeX/Gaelic/vocab/mwe.tex",
    "owner": "LaTeX",
    "severity": 8,
    "message": "Undefined control sequence.\n\\reserved@a ->\\@nil",
    "source": "LaTeX",
    "startLineNumber": 27,
    "startColumn": 1,
    "endLineNumber": 27,
    "endColumn": 65536
}]

这超出了我的宏能力。有人能帮忙吗？应该注意的是，这不是原始问题。为了生成不需要购买字体的 MWE，我一直取出直到没有错误，然后加回来得到这个。原始问题是：

\newfontfamily{\EtGoudy}{P22 Goudy Ampersands}
\DeclareTextFontCommand{\GoudyEt}{\EtGoudy}
\newfontfamily{\cVirgi}{P22 Virginian}
\DeclareTextFontCommand{\Virgic}{\cVirgi}
\def\dispEt{\GoudyEt{c}\kern -3pt{\vspace{-0.01ex}\huge\Virgic{c}}.}
\def\Etc{\textnormal{\dispEt}}

替换\test为\Etc，结果类似。

Answer 1

注意，你应该总是以多行形式显示 TeX 错误，因为换行符对于理解消息至关重要，它们标记哪个命令未定义

! Undefined control sequence.
\reserved@a ->\@nil 
                    
l.29 ...exy{one \test}{two \test s}{three \test s}
                                                  
?

您使用了 TeX 基元定义，导致命令在扩展上下文中中断。如果您使用，\NewDocumentCommand您将\protected在此类构造中获得安全的命令。

运行没有错误

\documentclass[12pt]{report}
\usepackage{xifthen}
\usepackage{xstring}

\NewDocumentCommand\test{}{\textnormal{test}}

\newcounter{wordCount}
\setcounter{wordCount}{0}
\newcounter{AllWord}
\setcounter{AllWord}{0}

\NewDocumentCommand{\exy}{ m m m}{%
    \StrCount{#2}{,}[\comma]%%%%%%%%%%%%%%
    \StrCount{#2}{?}[\qmark]%%%%%%%%%%%%%%
    \ifthenelse{\qmark > 0}{%
        \addtocounter{wordCount}{\comma + \qmark}%%%%%%%%%%%%%%
        \addtocounter{AllWord}{\comma + \qmark}%%%%%%%%%%%%%%
    }{%
        \addtocounter{wordCount}{\comma + \qmark + 1}%%%%%%%%%%%%%%
        \addtocounter{AllWord}{\comma + \qmark + 1}%%%%%%%%%%%%%%
    }%%%%%%%%%%%%%%
    \textbf{#2} (#3), ``#1''\\%
}

\begin{document}
    \test\par
    \exy{one \test}{two \test s}{three \test s}
\end{document}

但产生

Underfull \hbox (badness 10000) in paragraph at lines 29--30

由于位置错误\\，不应在段落末尾使用。（最好使用\par）

Answer 2

我不会使用xstring。代码中的主要问题是命令\Etc（非常）脆弱。

我的建议是使用来expl3计算逗号和问号，通过在它们处拆分文本并计算项目（并减一）。

该参数已完全扩展（但强命令尚未扩展）并被“净化”，因此诸如的命令\textnormal消失了。

\documentclass[12pt]{report}

\newcommand\test{\textnormal{test}}
\NewDocumentCommand\dispEt{}{\GoudyEt{c}\kern -3pt{\huge\Virgic{c}}.}
\NewDocumentCommand\Etc{}{\textnormal{\dispEt}}
\newcommand\GoudyEt{}% just for testing
\newcommand{\Virgic}{}% just for testing

\newcounter{wordCount}
\newcounter{AllWord}

\ExplSyntaxOn

\NewDocumentCommand{\exy}{m m m}
 {
  \hsmyers_xyz_exy:nnen { #1 } { #2 } { \text_purify:n { \text_expand:n { #2 } } } { #3 }
 }

\int_new:N \l_hsmyers_xyz_comma_int
\int_new:N \l_hsmyers_xyz_qmark_int

\cs_new_protected:Nn \hsmyers_xyz_exy:nnnn
 {
  \hsmyers_xyz_count:nnN { , } { #3 } \l_hsmyers_xyz_comma_int
  \hsmyers_xyz_count:nnN { ? } { #3 } \l_hsmyers_xyz_qmark_int
  \int_compare:nTF { \l_hsmyers_xyz_qmark_int > 0 }
   {
    \addtocounter{wordCount}
     {
      \int_eval:n { \l_hsmyers_xyz_comma_int + \l_hsmyers_xyz_qmark_int }
     }
    \addtocounter{AllWord}
     {
      \int_eval:n { \l_hsmyers_xyz_comma_int + \l_hsmyers_xyz_qmark_int }
     }
    }{%
    \addtocounter{wordCount}
     {
      \int_eval:n { \l_hsmyers_xyz_comma_int + \l_hsmyers_xyz_qmark_int + 1}
     }
    \addtocounter{AllWord}
     {
      \int_eval:n { \l_hsmyers_xyz_comma_int + \l_hsmyers_xyz_qmark_int + 1}
     }
   }
  \textbf{#2}~#4,~``#1''
 }
\cs_generate_variant:Nn \hsmyers_xyz_exy:nnnn { nne }

\cs_new_protected:Nn \hsmyers_xyz_count:nnN
 {
  \seq_set_split:Nnn \l_tmpa_seq { #1 } { #2 }
  \int_set:Nn #3 { \seq_count:N \l_tmpa_seq - 1 }
 }

\ExplSyntaxOff

\begin{document}

\test\par

\exy{one \Etc}{two \test \Etc{} s}{three \Etc{} s}

wordCount=\the\value{wordCount}

AllWord=\the\value{AllWord}

\exy{one \test}{two, three?}{three \test s}

wordCount=\the\value{wordCount}

AllWord=\the\value{AllWord}

\end{document}