30 l3 的 key 如何识别不用逗号分隔的

谢谢回答. 蹩脚的 l3key 是因为我把显示选项的功能放到了同一个命令, 通过 key 来控制是否把正确答案的序号显示为红色粗体, 水平有限, 所以比较蹩脚, 慢慢学习改进.

贴一下我那完整的蹩脚 sty, 见笑了.

\ProvidesPackage{choiceSXZLJ}
\RequirePackage{hlist}
\ExplSyntaxOn
\keys_define:nn {xxchoice}{
    隐藏答案.bool_set:N = \l_choice_隐藏答案_bool,
    隐藏答案.initial:n = false,
    A.bool_set:N = \l_choice_A_bool,
    A.initial:n = false,
    B.bool_set:N = \l_choice_B_bool,
    B.initial:n = false,
    C.bool_set:N = \l_choice_C_bool,
    C.initial:n = false,
    D.bool_set:N = \l_choice_D_bool,
    D.initial:n = false,

    unknown .code:n =,
}
\tl_map_inline:nn { ABCD }
{
    \exp_args:Nc \NewDocumentCommand { xxColor #1 } { } 
    {
        \bool_lazy_and:nnTF
        { \bool_not_p:n \l_choice_隐藏答案_bool }
        { \use:c { l_choice_ #1 _bool } }
        { { \color{red} \bfseries #1  } }
        { #1  }
    }
}
\NewDocumentCommand{\xxHlist}{m+m+m+m+m}{
    \begin{hlist}[pre~skip=0pt,item~skip=0pt,,item~offset={1.5em}, label=\Alpha {hlisti}.,pre~label={}]#1
        \hitem[\xxColorA~.] #2
        \hitem[\xxColorB~.] #3
        \hitem[\xxColorC~.] #4
        \hitem[\xxColorD~.] #5
    \end{hlist}
}
\NewDocumentCommand{\xxSinglePic}{m +m}
{
    \begin{flushleft}
    \hspace{-0.5em}
    \begin{minipage}{2em}
    \begin{center}
        #1
    \end{center}
    \end{minipage}
    \begin{minipage}{0.95\linewidth}
        #2
    \end{minipage}
    \end{flushleft}
}
\newlength{\lengthOfA}
\newlength{\lengthOfB}
\newlength{\lengthOfC}
\newlength{\lengthOfD}
\newlength{\lengthOfHalf}
\newlength{\lengthOfQuarter}
\newlength{\lengthMax}
\NewDocumentCommand{\xx}{s O{}+m+m+m+m}{%
    \group_begin:
    \keys_set:nn {xxchoice}{#2}
    \settowidth{\lengthOfA}{A.~#3~~~}
    \settowidth{\lengthOfB}{B.~#4~~~}
    \settowidth{\lengthOfC}{C.~#5~~~}
    \settowidth{\lengthOfD}{D.~#6~~~}
    %
    \ifthenelse{\lengthtest{\lengthOfA > \lengthOfB}}
        {\setlength{\lengthMax}{\lengthOfA}}
        {\setlength{\lengthMax}{\lengthOfB}}
    \ifthenelse{\lengthtest{\lengthMax < \lengthOfC}}
        {\setlength{\lengthMax}{\lengthOfC}}
        {}
    \ifthenelse{\lengthtest{\lengthMax < \lengthOfD}}
        {\setlength{\lengthMax}{\lengthOfD}}
        {}
    %
    \IfBooleanTF{#1}
    {
        \setlength{\lengthOfHalf}{0.5\linewidth}
        \setlength{\lengthOfQuarter}{0.25\linewidth}
    }{
        \setlength{\lengthOfHalf}{0.46\linewidth}
        \setlength{\lengthOfQuarter}{0.23\linewidth}
    }
    %
    \ifthenelse{\lengthtest{\lengthMax > \lengthOfHalf}}
    {%每行一个
        \IfBooleanTF{#1}
        {
            \xxSinglePic{\xxColorA}{#3}
            \xxSinglePic{\xxColorB}{#4}
            \xxSinglePic{\xxColorC}{#5}
            \xxSinglePic{\xxColorD}{#5}
        }
        {
            \xxHlist{1}{#3}{#4}{#5}{#6}
        }
    }
    {%
        \ifthenelse{\lengthtest{\lengthMax > \lengthOfQuarter}} % 
        {%每行2个
            \IfBooleanTF{#1}
            {
                \begin{center}
                \begin{tblr}{columns={c,0.5\linewidth},rows={m}}
                #3 & #4 \\
                \xxColorA & \xxColorB \\
                #5 & #6 \\
                \xxColorC & \xxColorD
                \end{tblr}
                \end{center}
            }
            {
                \xxHlist{2}{#3}{#4}{#5}{#6}
            }
        }
        {%每行4个
            \IfBooleanTF{#1}
            {
                \begin{flushleft}
                \begin{tblr}{columns={c,0.225\linewidth},rows={m}}
                #3 & #4 & #5 & #6 \\
                \xxColorA & \xxColorB & \xxColorC & \xxColorD
                \end{tblr}
                \end{flushleft}
            }
            {
                \xxHlist{4}{\mbox{#3}}{\mbox{#4}}{\mbox{#5}}{\mbox{#6}}
            }
    }}
    \group_end:
}
%
\keys_define:nn {choiceTable}{
    开始.int_set:N = \l__zlj_choiceTable_开始_int,
    开始.initial:n = 1,
    结束.int_set:N = \l__zlj_choiceTable_结束_int,
    结束.initial:n = 1,

    unknown .code:n =,
}
\tl_new:N \l__zlj_choice_content_tl 
\NewDocumentCommand \choiceTable{+O{} O{3em}}
{
    \keys_set:nn {choiceTable}{#1}
    \tl_clear:N \l__zlj_choice_content_tl 
    \tl_put_right:Nn \l__zlj_choice_content_tl { { \heiti 题号 } }
    \int_step_inline:nnnn { \int_use:N \l__zlj_choiceTable_开始_int }{1}{ \int_use:N \l__zlj_choiceTable_结束_int }
        { \tl_put_right:Nn \l__zlj_choice_content_tl { & ##1 } }
    \tl_put_right:Nn \l__zlj_choice_content_tl { \\ { \heiti 答案 } }
    \tl_put_right:Nx \l__zlj_choice_content_tl
        { \prg_replicate:nn { \l__zlj_choiceTable_结束_int - \l__zlj_choiceTable_开始_int } { & } }
    \begin{tblr} [ expand = \expandafter ] {vlines,hlines,columns={ #2,c },column{1}={3em,c} }
        \expandafter\empty\l__zlj_choice_content_tl
    \end{tblr}
}
\ExplSyntaxOff
\endinput
%