在宏中传递参数

Question

我有一个在文档中反复调用的宏

\newcommand\foo[1]{Process #1}
\newcommand\var[2]{Do something with #1 and #2, and then call '\foo{#2}', and again '\foo{#2}', and once again '\foo{#2}'}

宏在foo内部被多次扩展，var相同的论点，人们可能会认为传递论点只是多余的，而且是可以避免的。

问题：是否有可能有一个版本，foo当var定义为

\newcommand\var[2]{Do something with #1 and #2, and then call '\foo', and again '\foo', and once again '\foo'}

会导致第一个例子的结果吗？

平均能量损失

\documentclass[]{article}

\newcommand\foo[1]{Process #1}
\newcommand\var[2]{Do something with #1 and #2, and then call '\foo{#2}', and again '\foo{#2}', and once again '\foo{#2}'}

\begin{document}

\var{x}{y}

\end{document}

这是输出

我希望得到相同的结果，定义var为

\newcommand\var[2]{Do something with #1 and #2, and then call '\foo', and again '\foo', and once again '\foo'}

Answer 1

原帖者要求我将评论转换成答案。但答案均未给出原帖者所期望的内容。

问题是，我认为没有办法在不执行某些操作的情况下获取#2或将其等效值存入。但这只能在调用之后或通过某些预宏调用来实现。\foo#2\var\var

我在下面的 MWE 中展示了这两种替代方案。

\documentclass[]{article}
\begin{document}
Original approach of OP

\newcommand\foo[1]{Process #1}
\newcommand\var[2]{Do something with #1 and #2, and then call '\foo{#2}', and again '\foo{#2}', and once again '\foo{#2}'}

\var{x}{y}

\hrulefill

Requires a leading \verb|\def| inside of \verb|\var|

\renewcommand\var[2]{\def\foo{Process #2}Do something with #1 and #2, and then call '\foo', and again '\foo', and once again '\foo'}

\var{x}{y}

\hrulefill

Defines \verb|\var| as desired, but requires invocation of \verb|\setvar|

\renewcommand\var[2]{Do something with #1 and #2, and then call '\foo', and again '\foo', and once again '\foo'}

\newcommand\setvar[2]{\def\foo{Process #2}\var{#1}{#2}}

\setvar{x}{y}
\end{document}