使用属性列表的键进行 For 循环

Question

我正在使用属性列表，并且希望能够创建一个命令来生成用于生成 for 循环的键列表。我目前使用 \prop_map_inline 来生成所有键，但如果我在 for 循环中使用它，它会被解释为单个项目，而不是多个项目的集合。

这是一个示例代码：

\documentclass{article}
\usepackage{ifthen}
\usepackage{xparse}

\ExplSyntaxOn
    \prop_new:N \g_persons_prop
    
    % Create a new person
    \NewDocumentCommand{\CreatePerson}{m} {
        \prop_gput:Nnn \g_persons_prop { #1 }
    }
    
    % Gets all persons
    \NewDocumentCommand{\GetAllPersonKeys}{}{
        \prop_map_inline:Nn \g_persons_prop {
            ##1, 
        }
    }
\ExplSyntaxOff

\CreatePerson{jd}{John Doe}
\CreatePerson{ad}{Albert Dull}
\CreatePerson{bu}{Ben Under}

\begin{document}
    I would like to have this:
    \makeatletter
        \begin{itemize}
            \@for\sun:={jd, ad, bu}\do{\item We have person: \sun. }
        \end{itemize}
     \makeatother
    
    But I get this instead:
    
    \makeatletter
        \begin{itemize}
            \@for\sun:={\GetAllPersonKeys}\do{\item We have person: \sun. }
        \end{itemize}
     \makeatother   

\end{document}

Answer 1

您也可以映射 expl3 中的键：

\documentclass{article}
\usepackage{ifthen}
\usepackage{xparse}

\ExplSyntaxOn
    \prop_new:N \g_persons_prop

    % Create a new person
    \NewDocumentCommand{\CreatePerson}{m} {
        \prop_gput:Nnn \g_persons_prop { #1 }
    }

    \NewDocumentCommand{\MapAllPersonKeys}{m}{
        \prop_map_inline:Nn \g_persons_prop {
           #1
        }
    }
    
    
\ExplSyntaxOff

\CreatePerson{jd}{John Doe}
\CreatePerson{ad}{Albert Dull}
\CreatePerson{bu}{Ben Under}

\begin{document}
    I would like to have this:
    
      \makeatletter
        \begin{itemize}
            \@for\sun:={jd, ad, bu}\do{\item We have person: \sun. }
        \end{itemize}
     \makeatother
     
      \begin{itemize}
           \MapAllPersonKeys{\item we have person: #1!}
      \end{itemize}
    

\end{document}