Unable to show the macro/command definition, when the macro/command defined with optional argument

Question

For example, I define two commands. \mytesta with optional argument, \mytestb without optional argument. Now using \cs_meaning:N to show the command definition. The result is like this:

\documentclass{article}
\newcommand{\mytesta}[2][]{#2\quad#1}
\newcommand{\mytestb}[2]{#1\quad#2}
\setlength{\parindent}{0pt}
\ExplSyntaxOn
\cs_set_eq:NN \checkmeaning \cs_meaning:N
\ExplSyntaxOff
\begin{document}
\Large
\section{Testing}
\par\mytesta[default]{argument}
\par\mytestb{argument}{default}
\vskip 2em
\par\verb|\mytesta:|
{\par\ttfamily\checkmeaning \mytesta}
\par\verb|\mytestb:|
{\par\ttfamily\checkmeaning \mytestb}
\vskip 2em
\par\verb|Is possible to show:|
\par\verb|"[#1]#2->#2\quad #1" in \mytesta?|
\end{document}

What do you want exactly? The command is really defined like that. If you want to show the latter then show the command with csname \mytesta (you need to know some catcode manipulation to show that) — user202729, May 10 '22 at 00:36
Alternatively just use latexdef, if what you really want to do is to show the definition of an existing command. — user202729, May 10 '22 at 00:37
@user202729 I want to check the definition of some existing commands in certain packages. But it turn out that if the command is defined with optional argument, I unable to see the latter definition. — Tom, May 10 '22 at 00:43
@Tom Use \ShowCommand\yourcommand. It will print the full definition in the terminal — Phelype Oleinik, May 10 '22 at 00:51
@Phelype Thank you, is possible to print them in the document? As said by user202729 might need some catcode manipulations with csname or something? — Tom, May 10 '22 at 00:59
@Tom For the particular case of macros defined with \newcommand and an optional argument, you can do \cs_new:Npn\checkmeaning#1{\cs_meaning:c{\token_to_str:N#1}}. I don't know... Maybe a \CommandMeaning would be useful... — Phelype Oleinik, May 10 '22 at 01:10
macros - Where do I find out how a command/environment is defined? - TeX - LaTeX Stack Exchange — user202729, May 10 '22 at 14:27
As I mentioned in a previous comment, latexdef (see linked answer) could already resolve through those "standard" indirect layers. — user202729, May 10 '22 at 14:28
Why you want show in document? Just go to source code and copy paste the definition (also have proper linebreak) — user202729, May 10 '22 at 14:28
@user202729 You are right. There are a lot ways to see them. — Tom, May 10 '22 at 15:39

Unable to show the macro/command definition, when the macro/command defined with optional argument

0 Answers0