prop 與 clist ：prop_get 回傳 clist，prop_map_inline 不回傳？

Question

我確信我錯過了一些瑣碎的事情（仍在學習 LaTeX3），但這看起來很奇怪：prop_map_inline 不會以 clist 的形式傳回值，即使它們是？

\documentclass{article}

\begin{document}

\ExplSyntaxOn
\prop_new:N \someProp

% put some data into prop:
\clist_set:Nn \l_tmpa_cl {a,b,c}
\clist_use:Nn \l_tmpa_cl {\ ---\ }
\prop_put:NnV \someProp {keyA} {\l_tmpa_cl}
\par

\clist_set:Nn \l_tmpa_cl {u,v,w,x,y,z}
\clist_use:Nn \l_tmpa_cl {\ ---\ }
\prop_put:NnV \someProp {keyB} {\l_tmpa_cl}
\par

% Direct access works fine; I get back a clist:
\prop_get:NnN \someProp {keyA} \l_tmpb_cl
\clist_use:Nn \l_tmpb_cl {\ ---\ }
\par 

% When iterating over property, value is no longer
% a clist, but just a string? 
\prop_map_inline:Nn \someProp { Key\ #1; \ 
  Values\ list:\ \clist_use:Nn #2 {\ ---\ } 
  \par } 

\prop_log:N \someProp

\ExplSyntaxOff

\end{document}

記錄檔:

The property list \someProp contains the pairs (without outer braces):
>  {keyA}  =>  {a,b,c}
>  {keyB}  =>  {u,v,w,x,y,z}.

這似乎是應該的。 ??

Answer 1

您需要的\clist_use:nnas#2不是一個變數（如\l_tmpa_clist），而只是一個標記列表（a,b,c）。

\documentclass{article}

\begin{document}

\ExplSyntaxOn
\prop_new:N \l_karl_some_prop

% put some data into prop:
\clist_set:Nn \l_tmpa_clist {a,b,c}
\clist_use:Nn \l_tmpa_clist {\ ---\ }
\prop_put:NnV \l_karl_some_prop {keyA}\l_tmpa_clist
\par

\clist_set:Nn \l_tmpa_clist {u,v,w,x,y,z}
\clist_use:Nn \l_tmpa_clist {\ ---\ }
\prop_put:NnV \l_karl_some_prop {keyB}\l_tmpa_clist
\par


\prop_map_inline:Nn \l_karl_some_prop 
 { 
   Key\ #1; \ 
   Values\ list:\  \clist_use:nn {#2} {\ ---\ } 
   \par 
 } 

\ExplSyntaxOff

\end{document}