我尝试重新定义\selectlanguage如下polyglossia：
\LetLtxMacro{\selectlanguage@original}{\selectlanguage}
\renewcommand{\selectlanguage}[2][]{\selectlanguage@original[#1]{#2}}
据我了解，这个新版本的\selectlanguage行为应该与以前完全一样。但是我一直收到错误
Package polyglossia: language * is not loaded. Please load it before using it..
我怎样才能正确应用这个重新定义，即\selectlanguage重建\selectlanguage@original？
下面是 MWE。
%! TEX program = xelatex
\documentclass{article}
\usepackage{polyglossia}
\setdefaultlanguage{english}
\setotherlanguage{french}
\makeatletter
\usepackage{letltxmacro}
\LetLtxMacro{\selectlanguage@original}{\selectlanguage}
\renewcommand{\selectlanguage}[2][]{\selectlanguage@original[#1]{#2}}
\makeatother
\begin{document}
\selectlanguage{french}
Text.
\selectlanguage{english}
Text.
\end{document}
答案1
您已删除对*表单的支持，并进行了重新定义
\selectlanguage * {english}
是
\selectlanguage@original[]{*}{english}
并导致错误
! Package polyglossia Error: language * is not loaded. Please load it before us
ing it..
See the polyglossia package documentation for explanation.
Type H <return> for immediate help.
...
l.2 \selectlanguage *
{english}
?