用宏替换 \begin{comment} 和 \end{comment}，拼写更短

Question 1

这样的事情对你有用吗？

\documentclass{article}
\usepackage{xcolor}
\long\def\ansin#1\sna{\color{red}#1\color{black}}
\long\def\ansex#1\sna{}
\newcommand\excludecomment{\let\ans\ansex}
\newcommand\includecomment{\let\ans\ansin}
\excludecomment
\begin{document}
Hello!\\
\ans
I say hello because I have no better idea !\\
\sna
\includecomment
How are you?\\
Separate \ans lines are not \sna required.
\end{document}

Answer

这样的事情对你有用吗？

\documentclass{article}
\usepackage{xcolor}
\long\def\ansin#1\sna{\color{red}#1\color{black}}
\long\def\ansex#1\sna{}
\newcommand\excludecomment{\let\ans\ansex}
\newcommand\includecomment{\let\ans\ansin}
\excludecomment
\begin{document}
Hello!\\
\ans
I say hello because I have no better idea !\\
\sna
\includecomment
How are you?\\
Separate \ans lines are not \sna required.
\end{document}

Question 2

\includecomment对于通过/定义的环境\excludecomment，需要检测此类环境实例的结束。

检测机制“假定”表示环境结束的短语可以通过在环境名称前面添加短语\end{并附加短语来得出}。

检测机制不会触发事物的扩展来检测该短语，但“期望”找到它逐字。

因此，使用
      \ans→\begin{detail}和\sna→\end{detail}
你可以执行
      \excludecomment{detail}... \ans... \end{detail}
，但是你不能做
      \excludecomment{detail}... \ans... \sna   ：

\documentclass[10pt]{article}
\usepackage{comment}

\begin{document}

\newcommand{\ans}{\begin{detail}}
\newcommand{\sna}{\end{detail}}

\excludecomment{detail}
%\includecomment{detail}


Hello !\\
\ans
I say hello because I have no better idea !\\
\end{detail}
How are you ?

\end{document}

顺便一提：

\excludecomment{detail}…… \begin{detail}（和\end⎵{detail}之间的空格）也不起作用。它与（没有空格）不一样。\end{detail}\end{detail}

如果你真的绝对希望\ans..像..\sna一样工作，你可以定义一个命令来保存当前颜色并破解命令和（它们是-environment 的组件），以便让-environment 扫描短语而不是短语。你需要对事物被标记化的 catcode-régime 挑剔——因此这很棘手。\begin{detail}\end{detail}\ans\Enddetailtest\AfterdetailCommentdetaildetail\sna\end{detail}

你既不能做\begin{detail}..\sna也不能做\ans..。\end{detail}

使用\ans..时适用与..\sna相同的规则。例如，必须独占一行，前面不能有空格，...\begin{detail}\end{detail}\sna

\documentclass[10pt]{article}
\usepackage[dvipsnames]{xcolor}
\usepackage{comment}

\setlength\parindent{0mm}

\begingroup
\makeatletter
\catcode`\^^M=12\relax%%%
\@firstofone{%
  \endgroup%%%
  \newcommand{\ans}{%
    \let\savedEnddetailTest=\EnddetailTest%%%
    \let\savedAfterdetailComment=\AfterdetailComment%%%
    \colorlet{savedcurrentcolor}{.}%
    {%
     \escapechar=-1\relax%%%
     \expandafter%%%
    }\expandafter\def\expandafter\EnddetailTest\expandafter{\string\\sna}%
    \toks@\expandafter{%
      \AfterdetailComment%%%
      \let\EnddetailTest=\savedEnddetailTest%%%
      \let\AfterdetailComment=\savedAfterdetailComment%%%
      \color{savedcurrentcolor}%
    }%
    \edef\AfterdetailComment{\the\toks@}%
    \begin{detail}^^M\color{Plum}%
  }%
}%

\begin{document}

\includecomment{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

\bigskip

\hrule

\bigskip

\excludecomment{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

\end{document}

在上述示例中，使用 -command 后，\ans返回字符的 catcode（^^M在 TeX 的^^-notation 中）会更改为 12，以便将颜色规范处理为出现在新行上。

因此，使用\ans..\sna命令时事物为颜色Plum，而使用\begin{detail}..命令时\end{detail}事物为颜色black。

Plum如果您希望同时使用\ans..\sna和\begin{detail}..的颜色\end{detail}，则可以省略这个 catcode-trickery 并detail根据\specialcomment而不是来定义环境\includecomment：

\documentclass[10pt]{article}
\usepackage[dvipsnames]{xcolor}
\usepackage{comment}

\setlength\parindent{0mm}

\newcommand{\ans}{%
  \let\savedEnddetailTest=\EnddetailTest
  \let\savedAfterdetailComment=\AfterdetailComment
  {%
   \escapechar=-1\relax
   \expandafter
  }\expandafter\def\expandafter\EnddetailTest\expandafter{\string\\sna}%
  \csname toks@\endcsname\expandafter{%
    \AfterdetailComment
    \let\EnddetailTest=\savedEnddetailTest
    \let\AfterdetailComment=\savedAfterdetailComment
  }%
  \edef\AfterdetailComment{\the\csname toks@\endcsname}%
  \begin{detail}%
}%

\begin{document}

\specialcomment{detail}%
               {\colorlet{savedcurrentcolor}{.}\color{Plum}}%
               {\color{savedcurrentcolor}}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

\bigskip

\hrule

\bigskip

\excludecomment{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

Hello !\\
\ans
I say hello because I have no better idea !\\
\sna

Hello !\\
\begin{detail}
I say hello because I have no better idea !\\
\end{detail}

\end{document}

对于这个问题：

有没有办法定义 \sna 以使其完成这项工作？

在前两个例子中，命令\sna根本没有定义。;-)

在编写此答案和编译/测试代码时，根据.log文件，正在使用以下文件/版本/版本：

This is pdfTeX, Version 3.14159265-2.6-1.40.21 (TeX Live 2020) (preloaded format=pdflatex 2021.1.17)  29 JAN 2021 23:13
LaTeX2e  patch level 4
L3 programming layer <2021-01-09> xparse <2020-03-03>
[...]
Document Class: article 2020/04/10 v1.4m Standard LaTeX document class
[...]
Package: xcolor 2016/05/11 v2.12 LaTeX color extensions (UK)
[...]
File: dvipsnam.def 2016/06/17 v3.0m Driver-dependent file (DPC,SPQR)
[...]
File: l3backend-pdftex.def 2021-01-09 L3 backend support: PDF output (pdfTeX)
[...]
/usr/local/texlive/2020/texmf-dist/tex/latex/comment/comment.sty

.log 文件仅显示文件的位置comment.sty，而不是版本。

查看指定位置的文件显示：

% Comment.sty   version 3.8, July 2016
% copyright 1998-2016 Victor Eijkhout

Answer