如何用参数替换字符串中的占位符？

Question 1

使用 expl3 你可以定义一个\MyReplace带有三个参数的命令，

⟨英文原文⟩
⟨中文文本⟩
⟨英文/中文文本中常用替换 {1}、{2}、{3}、… 的文本短语列表⟩

，它实际上包含括号嵌套的未分隔参数列表。

取决于迭代是否\englishtrue发生\englishfalse在⟨英文文本⟩或⟨中文文本⟩的未限定参数上，其中每个元素处理如下：

如果它的第一个标记是，:则假定它表示一个非常见的文本短语，并且它会被:删除。
如果它的第一个标记不是，:则假定它表示数字 k，并且如果该列表有第 k^个元素，则传递⟨常用文本短语列表⟩的第 k^个元素。

起初我考虑过反过来做，即:⟨number⟩用而不是:⟨non-common text phrase⟩，但随后出现了一个问题，即如何处理非常见文本短语以为前导的情况:，而不会错误地将其作为 :⟨number⟩ 传递给处理，这可能会导致低级 TeX 错误消息。

\documentclass{article}

\ExplSyntaxOn
\bool_new:N \l_english_bool
\cs_new_protected:Npn \englishtrue {\bool_set_true:N \l_english_bool}
\cs_new_protected:Npn \englishfalse {\bool_set_false:N \l_english_bool}
\cs_new_protected:Npn \enzh #1#2 {\bool_if:nTF \l_english_bool {#1}{#2}}
\cs_new_protected:Npn \MyReplace #1#2#3
  {
    \bool_if:nTF \l_english_bool
    {\tl_map_tokens:nn {#1} }
    {\tl_map_tokens:nn {#2} }
    {\mymodule_get_kth_arg:nn{#3}}
  }
\cs_new:Nx \mymodule_get_kth_arg:nn
  {
    \exp_not:N\tl_if_blank:nF {#2} {
      \exp_not:N\tl_if_head_eq_meaning:nNTF 
         {#2}\token_to_str:N :
         {\exp_not:N\tl_tail:n {#2}}
         {\exp_not:N\tl_item:nn{#1}{#2}}
    }
  }
\ExplSyntaxOff

\begin{document}

\englishtrue

\enzh{English text}{Chinese text}

\MyReplace{ {1}{: }{2}{: English text A }{2}{: English text B }{5}{: English text C }{4}{: English text D }{3} }%
          { {2}{: }{1}{: Chinese Text text A }{1}{: Chinese text B }{3}{: Chinese Text text C }{4}{: Chinese text D }{5} }%
          { 
             {Common Phrase 1} 
             {Common Phrase 2}
             {Common Phrase 3}
             {Common Phrase 4}
             {Common Phrase 5}
          }

\bigskip

\englishfalse

\enzh{English text}{Chinese text}

\MyReplace{ {1}{: }{2}{: English text A }{2}{: English text B }{5}{: English text C }{4}{: English text D }{3} }%
          { {2}{: }{1}{: Chinese Text text A }{1}{: Chinese text B }{3}{: Chinese Text text C }{4}{: Chinese text D }{5} }%
          { 
             {Common Phrase 1}
             {Common Phrase 2}
             {Common Phrase 3}
             {Common Phrase 4}
             {Common Phrase 5}
          }

\end{document}

在上述示例的 ⟨英文文本⟩ 和 ⟨中文文本⟩ 中，{: }空格都用作非常用文本短语。您也可以将空格用作另一个常用文本短语，然后执行

\MyReplace{ {1}{6}{2}{: English text A }{2}{: English text B }{5}{: English text C }{4}{: English text D }{3} }%
          { {2}{6}{1}{: Chinese Text text A }{1}{: Chinese text B }{3}{: Chinese Text text C }{4}{: Chinese text D }{5} }%
          { 
             {Common Phrase 1}
             {Common Phrase 2}
             {Common Phrase 3}
             {Common Phrase 4}
             {Common Phrase 5}
             { }
          }

#1如果您更喜欢通过, #2, ... , #11... 而不是{1}, {2}, ... , ...来表示常见的文本短语/替换，{11}并且如果可扩展性不是问题，那么您可以使用 l3regex 的正则表达式。

在以下示例中，正则表达式将搜索#以一系列数字0, 1, 2, 3, 4, 5, 6, 7, 8,9结尾，并以一个可选斜杠结尾，/这样您就可以将属于常用文本短语/替换列表元素编号的数字与属于要传递的文本的数字分开 - 因此，如果您希望在文本中紧跟在常用文本短语后面/紧跟在表示的替换后面出现斜杠#⟨sequence of digits denoting the number of the common text phrase/replacement⟩，则需要输入两个斜杠：
#⟨sequence of digits denoting the number of the common text phrase/replacement⟩//The second one of these slashes goes into the text. The first one is removed as "digit"-separator":

\documentclass{article}

\ExplSyntaxOn
\bool_new:N \l_english_bool
\tl_new:N \l_mymodule_replacementlist_tl
\tl_new:N \l_mymodule_textphrase_tl
\cs_new_protected:Npn \englishtrue {\bool_set_true:N \l_english_bool}
\cs_new_protected:Npn \englishfalse {\bool_set_false:N \l_english_bool}
\cs_new_protected:Npn \enzh #1#2 {\bool_if:nTF \l_english_bool {#1}{#2}}
\cs_new_protected:Npn \MyReplace #1#2#3
  {
    \bool_if:nTF \l_english_bool
    {\tl_set:Nn\l_mymodule_textphrase_tl {#1} }
    {\tl_set:Nn\l_mymodule_textphrase_tl {#2} }
    \tl_set:Nn \l_mymodule_replacementlist_tl {#3}
    % \cA. denotes any active character; \cC. denotes any control sequence token, 
    % so the following prepends \noexpand to tokens that might be expandable:
    \regex_replace_all:nnN {(?:\cA.|\cC.)}{\c{exp\_not\:N}\0}\l_mymodule_textphrase_tl
%    \tl_show:N \l_mymodule_textphrase_tl
    % Replace any #<digit sequence><optional slash> of category 6 that is preceeded by an even amount of hashes 
    % by \tl_\item:Nn \l_mymodule_replacementlist_tl {<digit sequence>}:
    \regex_replace_all:nnN {  ((?:\G|[^\cP.])(?:[\cP.][\cP.])*)  [\cP.]   (\cO[\d]+)\cO\/?  }
                           {\1 \c{tl\_item\:Nn} \c{l\_mymodule\_replacementlist\_tl} \cB\{ \2 \cE\}}
                           \l_mymodule_textphrase_tl
%    \tl_show:N \l_mymodule_textphrase_tl
    % Expand the token list to get the token-list-items and halve doubled hashes:
    \exp_args:NNx \tl_set:Nn \l_mymodule_textphrase_tl {\tl_use:N \l_mymodule_textphrase_tl }
%    \tl_show:N \l_mymodule_textphrase_tl
    \tl_use:N \l_mymodule_textphrase_tl
  }
\ExplSyntaxOff

\begin{document}

\tableofcontents

\englishtrue

\MyReplace{\section{#1 English text #2}}
          {\section{#2 Chinese text #1}}
          {
             {Common 1} % <- this is #1
             {Common 2} % <- this is #2
          }

\enzh{English text}{Chinese text}

\bigskip

\MyReplace{#1 #2 English text A #2//English text B #5 English text C #4 English text D #3/7 is a nice digit.}%
          {#2 #1 Chinese Text text A #1//Chinese text B #3 Chinese Text text C #4 Chinese text D #5/7 is a nice digit.}%
          { 
             {Common Phrase 1} % <- this is #1
             {Common Phrase 2} % <- this is #2
             {Common Phrase 3} % <- this is #3
             {Common Phrase 4} % <- this is #4
             {Common Phrase 5} % <- this is #5
          }

\bigskip

\MyReplace{\def\MACRO##1##2{#1 English text #2}}%
          {\def\MACRO##1##2{#2 Chinese text #1}}%
          { 
             {Common Phrase 1, Argument 1: #1, Argument 2: #2} % <- in the two arguments above this is #1
             {Common Phrase 2, Argument 1: #1, Argument 2: #2} % <- in the two arguments above this is #2
          }%
{\tt\frenchspacing\string\MACRO: \meaning\MACRO}

\englishfalse

\MyReplace{\section{#1 English text #2}}
          {\section{#2 Chinese text #1}}
          {
             {Common 1} % <- this is #1
             {Common 2} % <- this is #2
          }

\enzh{English text}{Chinese text}

\bigskip

\MyReplace{#1 #2 English text A #2//English text B #5 English text C #4 English text D #3/7 is a nice digit.}%
          {#2 #1 Chinese Text text A #1//Chinese text B #3 Chinese Text text C #4 Chinese text D #5/7 is a nice digit.}%
          { 
             {Common Phrase 1} % <- this is #1
             {Common Phrase 2} % <- this is #2
             {Common Phrase 3} % <- this is #3
             {Common Phrase 4} % <- this is #4
             {Common Phrase 5} % <- this is #5
          }

\bigskip

\MyReplace{\def\MACRO##1##2{#1 English text #2}}%
          {\def\MACRO##1##2{#2 Chinese text #1}}%
          { 
             {Common Phrase 1, Argument 1: #1, Argument 2: #2} % <- in the two arguments above this is #1
             {Common Phrase 2, Argument 1: #1, Argument 2: #2} % <- in the two arguments above this is #2
          }%
{\tt\frenchspacing\string\MACRO: \meaning\MACRO}

\end{document}

如果您按照这种方式执行操作并将其用作\MyReplace宏的 ⟨定义⟩ 的替换文本/⟨平衡文本⟩的组成部分，则#表示常用文本短语/替换的数量的哈希值需要加倍，就像在 ⟨定义⟩ 内嵌套 ⟨定义⟩ 时表示参数的哈希值需要加倍一样。

Answer