末尾附有作者参考的引文

Question

我已经重新定义了引用环境以允许我将作者放在引用的末尾，但我的代码中某处有一个错误，有人可以检查一下：

%Add source argument to quote
\let\oldquote\quote
\newsavebox\first
\newsavebox\second
\renewenvironment{quote}[2][0]
  {\savebox\second{#1}
   \savebox\first{#2}
  \begin{oldquote}}
  {\smallskip\par\hfill(\usebox\first ~---~\usebox\second)\bigskip\break
  \end{oldquote}}

如果我尝试使用超过 6 个，我会收到“嵌套太深”错误，所以我认为我没有正确结束环境，但我找不到错误。

Answer 1

当 LaTeX 发现\end{oldquote}它时，它只会结束该组，而不会结束（原始）quote环境，因为\endoldquote没有定义。

同时添加

\let\endoldquote\endquote

删除最后的\break，其唯一的作用是发出“Underfull \hbox(badness 10000)”警告。

---

目前还不清楚为什么更新的quote环境有一个可选参数：将默认值设置0为

\begin{quote}{Somebody}
<text>
\end{quote}

打印“（Somebody — 0）”，这似乎不是我想要的。

也可以看看引用环境并在末尾引用对于一个非常相似的问题。

---

可能的改进：

\documentclass{article}

\let\oldquote\quote
\let\endoldquote\endquote
\renewenvironment{quote}[2][]
  {\if\relax\detokenize{#1}\relax
     \def\quoteauthor{#2}%
   \else
     \def\quoteauthor{#2~---~#1}%
   \fi
   \oldquote}
  {\par\nobreak\smallskip\hfill(\quoteauthor)%
   \endoldquote\addvspace{\bigskipamount}}

\begin{document}

\begin{quote}{Somebody}
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
\end{quote}

\begin{quote}[Somewhere]{Somebody}
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
\end{quote}

\end{document}

\par请注意和之间的反转\smallskip，并添加了\nobreak以避免在引用和归因之间出现分页符。无需将参数存储在框中；将它们存储在宏中更容易，当缺少可选参数时，宏将包含不同的内容。此外，最好\bigskip将 放在关闭（原始） 之后quote。

一种更简单的方法xparse，可以在“结束部分”中使用参数：

\documentclass{article}
\usepackage{xparse}

\let\oldquote\quote
\let\endoldquote\endquote

\RenewDocumentEnvironment{quote}{om}
  {\oldquote}
  {\par\nobreak\smallskip
   \hfill(#2\IfValueT{#1}{~---~#1})\endoldquote 
   \addvspace{\bigskipamount}}

\begin{document}

\begin{quote}{Somebody}
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
\end{quote}

\begin{quote}[Somewhere]{Somebody}
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
This is a quote This is a quote This is a quote
\end{quote}

\end{document}