定义新环境时出错

Question

我尝试使用\newenvironmentXeLaTeX 下的命令fontspec和polyglossia包，但新环境的关闭命令似乎无法识别。我该如何让它工作？

这是一个最简单的代码：

\documentclass[a4paper,12pt]{report}
\usepackage{fontspec}
\usepackage{polyglossia}

\setdefaultlanguage{english}
\setotherlanguage{tamil}

\setmainfont{Times New Roman}
\newfontfamily{\texttamil}{Nirmala UI}
\newenvironment{Tam}{\begin{texttamil}}{\end{texttamil}}

\begin{document}
text in Times 1
\begin{texttamil}
உடல் text in Nirmala 1
\end{texttamil}
text in Times 2
\Tam{உடல் text in Nirmala 2}
text in Times 3
\end{document}

“Times 3 中的文本”无法正确显示，因为它仍保留在 Nirmala 中。我得到：

! LaTeX Error: \begin{texttamil} on input line 18 ended by \end{document}.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...

l.20 \end{document}

?
[1] (Default.aux) )
(\end occurred inside a group at level 1)

### semi simple group (level 1) entered at line 18 (\begingroup)
### bottom levelstdin -> Default.pdf
[1]
27625 bytes written

我正在使用 Windows 10、Miktex 和 Texmaker。

Answer 1

当你这样做时\newenvironment{Tam}{...x...}{...y...}，你应该使用

\begin{Tam}
<text>
\end{Tam}

不是\Tam{<text>}。

也不要使用\begin{texttamil}。

\documentclass[a4paper,12pt]{report}
\usepackage{fontspec}
\usepackage{polyglossia}

\setdefaultlanguage{english}
\setotherlanguage{tamil}

\setmainfont{Times New Roman}
\newfontfamily{\texttamil}{Tamil Sangam MN} % the one I have
\newenvironment{Tam}
  {\texttamil\ignorespaces}
  {\ignorespacesafterend}

\begin{document}

text in Times 1
{\texttamil உடல் text in Nirmala 1}
text in Times 2
\begin{Tam}
உடல் text in Nirmala 2
\end{Tam}
text in Times 3

\end{document}