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为什么两个相同的列表有不同的元素数量？

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为什么两个相同的列表有不同的元素数量？

我创建了一个全局列表，并将4, 300两个元素分配给它。\clist_count:N显示其 2 个元素。如果我将此列表复制到本地列表，新列表的内容相同，但\clist_count:N仅显示 1 个元素。这是为什么？

\documentclass{scrlttr2}

\ExplSyntaxOn

\clist_clear_new:N \g__timelist_median_clist

\clist_new:N \l__timelist_median_clist

\NewDocumentCommand{\setlist}{m}
{
    \clist_gset:Nn \g__timelist_median_clist { #1 }
}

\NewDocumentCommand{\showlist}{}
{
    % set a comma separated list
    \clist_set:Nn \l__timelist_median_clist { \g__timelist_median_clist }
    
    g__timelist_median_clist:\ \clist_use:Nn \g__timelist_median_clist {,}\\
    count:\ \clist_count:N \g__timelist_median_clist\\
    
    l__timelist_median_clist:\ \clist_use:Nn \l__timelist_median_clist {,}\\
    count:\ \clist_count:N \l__timelist_median_clist\\
}

\ExplSyntaxOff

\begin{document}
    \setlist{4,300}
    \showlist
\end{document}

答案1

添加调试消息：

\documentclass{scrlttr2}

\ExplSyntaxOn

\clist_clear_new:N \g__timelist_median_clist

\clist_new:N \l__timelist_median_clist

\NewDocumentCommand{\setlist}{m}
{
    \clist_gset:Nn \g__timelist_median_clist { #1 }
}

\NewDocumentCommand{\showlist}{}
{
    % set a comma separated list
    \clist_set:Nn \l__timelist_median_clist { \g__timelist_median_clist }
    
    g__timelist_median_clist:\ \clist_use:Nn \g__timelist_median_clist {,}\\
    count:\ \clist_count:N \g__timelist_median_clist\\
    
    l__timelist_median_clist:\ \clist_use:Nn \l__timelist_median_clist {,}\\
    count:\ \clist_count:N \l__timelist_median_clist\\

\clist_show:N\l__timelist_median_clist
\clist_show:N\g__timelist_median_clist
}

\ExplSyntaxOff

\begin{document}
    \setlist{4,300}
    \showlist
\end{document}

然后你就会看到

The comma list \l__timelist_median_clist contains the items (without outer
braces):
>  {\g__timelist_median_clist }.

和

The comma list \g__timelist_median_clist contains the items (without outer
braces):
>  {4}
>  {300}.

因为\clist_set:Nn \l__timelist_median_clist { \g__timelist_median_clist }不会复制 2 个元素的列表，所以它会为全局列表创建一个由 csname 标记组成的新的 1 项列表。

你要\clist_set_eq:NN

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