lualatex 自动转换 --- 为自定义命令？

Question

这个答案显示一个间距合适的破折号。我想知道，如果使用 lualatex 及其所有功能，是否可以自动转换---为\dash上述链接中的命令？（例如使用切换\autodashON和\autodashOFF）

Answer 1

您可以---在输入中替换\dash

\documentclass{article}

\DeclareRobustCommand\dash{%
  \unskip\nobreak\thinspace\textemdash\allowbreak\thinspace\ignorespaces}

\directlua{
function dashes(s)
return string.gsub(s,'[-][-][-]','\string\\dash ')
end}

\def\autodashON{\directlua{%
luatexbase.add_to_callback("process_input_buffer",dashes,"spaced em dash")%
}}
\def\autodashOFF{\directlua{%
luatexbase.remove_from_callback("process_input_buffer","spaced em dash")%
}}

\setlength\parskip{20pt}
\setlength\parindent{0pt}
\begin{document}


One---two three --- four five.
One---two three --- four five.
One---two three --- four five.
One---two three --- four five.

\autodashON

One---two three --- four five.
One---two three --- four five.
One---two three --- four five.
One---two three --- four five.

\autodashOFF

One---two three --- four five.
One---two three --- four five.
One---two three --- four five.
One---two three --- four five.

\end{document}