How to define a command that defines another command?

Question

I have a command defined with xparse that looks like this:

\NewDocumentCommand{\ME}{sogd<>}{\added[id=ME,remark={#1}]{#2}}

(for the full code see Passing complicated argument patterns to a new command)

Now, I want this to be defined through another command, something like

\newcommand{\definerevision}[1]{
    \NewDocumentCommand{\#1}{gg}{\added[id=#1,remark={??#1}]{??#2}}
}

(?? means "what to put here?")

That is \definerevision{INITIAL} expands to define the command \NewDocumentCommand{\INITIAL}{gg}{\added[id=INITIAL,remark={#1}]{#2}} (e.g. in the header)

There are two potential problems, the first is to expand \#1 and the second is that the argument #1 has to be distinguished between the top level command or the nested command (how to distinguish).

Is there a way to define a command through another command using \newcommand or \xparse?

Answer 1

Defining a command within another command requires to use the \csname #1 \endcsname approach for the \NewDocumentCommand (or \newcommand as well) (assuming #1 is the name of the new command, as argument of the outer command), preceeded by \expandafter

If a command is defined within another one, all parameter arguments characters # have to be doubled, it i.e. ##1, ##2, etc.

\documentclass{article}
\usepackage{xparse}

\newcommand{\added}[1]{%
\Large%
\textbf{Arg was #1}%
}

\newcommand{\definerevision}[1]{%
  \expandafter\NewDocumentCommand\csname #1\endcsname{gg}{\added[id=#1,remark={##1}]{##2}}%
}


\definerevision{MOE}  

\definerevision{LARRY}  

\definerevision{CURLY}  
\begin{document}

\MOE{Added}{only this}

\LARRY{Added}{other more important stuff}

\CURLY{Screwed}{up the whole thing}


\end{document}