将许多数学宏包装到 `\ensuremath` 中

Question

我觉得更自然地引用\Phi，，，\alpha\simETC。外部数学模式与内部数学模式相同。IE写作：

Consider \Phi, \alpha{} and \sim{} in the following equation:
\begin{equation}
    \Phi \sim \alpha
\end{equation}

代替：

Consider $\Phi$, $\alpha$ and $\sim$ in the following equation:
\begin{equation}
    \Phi \sim \alpha
\end{equation}

我的幼稚方法是用它们自己的变体覆盖我需要的所有宏，如下所示这个帖子， 和：

\let\NPhi\Phi % native phi
\def\Phi{\ensuremath{\NPhi}}
\let\Nalpha\alpha % native alpha
\def\alpha{\ensuremath{\Nalpha}}
\let\Nsim\sim
\def\sim{\ensuremath{\Nsim}}
..

但这很繁琐。我该如何循环呢？这样：

\magiccommand{
    Phi,
    alpha,
    sim,
    ..}

会产生同样的结果吗？

Answer 1

您所需要的只是一个逗号分隔值的解析器。以下示例使用\comma@parse包kvsetkeys。宏会自动删除值开头和结尾的空格。

\documentclass{article}
\usepackage{kvsetkeys}
\makeatletter
\newcommand*{\EnsureMathDef}[1]{%
  % Throw error, if "\N#1" is already defined.
  \expandafter\@ifdefinable\csname N#1\endcsname{%
    % Save old meaning
    \expandafter
    \let\csname N#1\expandafter\endcsname
    \csname #1\endcsname
    % Define new macro
    \expandafter\edef\csname #1\endcsname{%
      \noexpand\ensuremath{%
        \expandafter\noexpand\csname N#1\endcsname
      }%
    }%
  }%
}
\comma@parse{
  Phi,
  alpha,
  sim,
}\EnsureMathDef
\makeatother

\begin{document}
Consider \Phi, \alpha{} and \sim{} in the following equation:
\begin{equation}
    \Phi \sim \alpha
\end{equation}
\end{document}

无附加包装

宏内核提供\@for。必须对行尾进行注释以避免出现多余的空格。

\documentclass{article}
\makeatletter
\@for\x:=%
  Phi,%
  alpha,%
  sim%
\do{%
  % Throw error if macro with prefix N is already defined.
  \expandafter\@ifdefinable\csname N\x\endcsname{%
    % Save old meaning
    \expandafter
    \let\csname N\x\expandafter\endcsname
    \csname\x\endcsname
    % Define new macro
    \expandafter\edef\csname\x\endcsname{%
      \noexpand\ensuremath{%
        \expandafter\noexpand\csname N\x\endcsname
      }%
    }%
  }%
}
\makeatother

\begin{document}
Consider \Phi, \alpha{} and \sim{} in the following equation:
\begin{equation}
    \Phi \sim \alpha
\end{equation}
\end{document}