LaTeX3: elegante Möglichkeit, Argumente (Token, Sterne, Verzierungen) an einen anderen Befehl weiterzuleiten

Question

Ich habe Mühe, einen LaTeX3-Befehl elegant zu definieren und seine Argumente (insbesondere Sterne, Token, Verzierungen) an einen anderen Befehl weiterzuleiten. Ich denke, ich könnte es vielleicht mit oder ähnlich zum Laufen bringen \expandonce, aber ich denke, es gibt eine bessere Lösung.

MWE:

\documentclass[]{article}

\NewDocumentCommand{\mycommand}{st't-t.e_O{}m}{%
  I am a command called \IfBooleanT{#1}{with a star, }\IfBooleanT{#2}{with a prime, }\IfBooleanT{#3}{with a dash, }\IfBooleanT{#4}{with a dot, }\IfNoValueTF{#5}{}{with an underscore (#5), } with the optional argument ``#6'' and with the mandatory argument ``#7''.
}

%% This fails:
% \NewDocumentCommand{\mynewcommand}{st't-t.e_O{}m}{%
%   \mycommand\IfBooleanT{#1}{*}\IfBooleanT{#2}{'}\IfBooleanT{#3}{.}\IfBooleanT{#4}{_{#4}}[foo#5]{#6}%
% }

%% This fails:
% \NewDocumentCommand{\mynewcommand}{st't-t.e_O{}m}{%
%   \mycommand#1#2#3#4[foo#5]{#6}%
% }

\begin{document}
\mycommand'_{below text}[I am optional]{yes}

How to define a new command so that mynewcommand behave like mycommand except that it prepends a string like "foo" in front of the optional argument?

% \mynewcommand*'-._{below text}[I am optional]{yes}


\end{document}

Answer 1

Ist es das, was Sie wollen? Ich glaube, Sie haben das Argument #3(das Argument s-) in übersehen \mynewcommand, also habe ich mir erlaubt, es hinzuzufügen.

\documentclass[]{article}

\NewDocumentCommand{\mycommand}{st't-t.e_O{}m}{%
  I am a command called \IfBooleanT{#1}{with a star, }\IfBooleanT{#2}{with a prime, }\IfBooleanT{#3}{with a dash, }\IfBooleanT{#4}{with a dot, }\IfValueT{#5}{with an underscore (#5), } with the optional argument ``#6'' and with the mandatory argument ``#7''.
}

% This works:
 \NewDocumentCommand{\mynewcommand}{st't-t.e_O{}m}{%
   \expandafter\mycommand\expanded{\IfBooleanT{#1}{*}\IfBooleanT{#2}{'}\IfBooleanT{#3}{-}\IfBooleanT{#4}{.}\IfValueT{#5}{\unexpanded{_{#5}}}\unexpanded{[foo#6]{#7}}}%
 }

%% This fails:
% \NewDocumentCommand{\mynewcommand}{st't-t.e_O{}m}{%
%   \mycommand#1#2#3#4[foo#5]{#6}%
% }

\begin{document}
\mycommand'_{below text}[I am optional]{yes}

How to define a new command so that mynewcommand behave like mycommand except that it prepends a string like "foo" in front of the optional argument?

\mynewcommand*'-._{below text}[I am optional]{yes}


\end{document}

Answer 2

Das tun Sie nicht. \NewDocumentCommandDafür ist es nicht gedacht.

Korrigieren Sie jedenfalls zuerst die Argumente in \mynewcommand: Ihre Liste ist ungültig.

\documentclass[]{article}

\NewDocumentCommand{\mycommand}{st't-t.e_O{}m}{%
  I am a command called
  \IfBooleanT{#1}{with a star, }%
  \IfBooleanT{#2}{with a prime, }%
  \IfBooleanT{#3}{with a dash, }%
  \IfBooleanT{#4}{with a dot, }%
  \IfValueT{#5}{with an underscore (#5), }
  with the optional argument ``#6'' and with the mandatory argument ``#7''.
}

\NewDocumentCommand{\mynewcommand}{st't-t.e{_}O{}m}{%
  \expanded{%
    \mycommand
    \IfBooleanT{#1}{*}%
    \IfBooleanT{#2}{'}%
    \IfBooleanT{#3}{-}%
    \IfBooleanT{#4}{.}
    \IfValueT{#5}{_{\unexpanded{#5}}}%
    [foo\unexpanded{#6}]%
    {\unexpanded{#7}}%
  }%
}


\begin{document}
\mycommand'_{below text}[I am optional]{yes}

How to define a new command so that mynewcommand behave like mycommand except that it prepends a string like "foo" in front of the optional argument?

\mynewcommand*'-._{below text}[I am optional]{yes}

\end{document}