在将宏作为参数 之前如何强制\myget{second}扩展，这对我来说似乎是个问题。按应有的方式工作。\qrcode{xxx}\qrcode{foobar}
\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{qrcode}
\usepackage{xstring}
\def\Testmap{
{first}{blue}
{second}{red}
{foo.bar}{orange}
{4}{violet}
{bla}{green}
{6}{violet}
{7}{violet}
{8}{black}
}
\def\xget#1#2{\expandafter\xgetimpl#1{#2}{}\xget{#1}{#2}}%
\def\xgetimpl#1#2#3\xget#4#5{%
\IfEq{#5}{#1}{#2}{\xgetimpl#3\xget{#4}{#5}}%
}%
\protect\def\myget#1{\xget{\Testmap}{#1}}%
\begin{document}
\qrcode{\myget{second}} %%%% !!!!!!!!!!!!
% \myget{second} %%%% this works fine (prints 'red' as expected)
\end{document}
我尝试在这段代码的几个地方放置几个\protect,\expandafter和 whatever，但都不起作用，也没有提示我下一步该看哪里。使用\edef\tmp{\myget{second}}也没什么用。
以下是 pdflatex *.log 文件的相关部分：
! Undefined control sequence.
\in@ #1#2->\begingroup \def \in@@
##1#1{}\toks@ \expandafter {\in@@ #2{}{}#1...
l.27 \qrcode{\myget{second}}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
! Illegal parameter number in definition of \qr@texttoencode.
<to be read again>
1
l.27 \qrcode{\myget{second}}
You meant to type ## instead of #, right?
Or maybe a } was forgotten somewhere earlier, and things
are all screwed up? I'm going to assume that you meant ##.
! Undefined control sequence.
\in@ ...f \in@@ ##1#1{}\toks@ \expandafter {\in@@
#2{}{}#1}\edef \in@@ {\the...
l.27 \qrcode{\myget{second}}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
! Undefined control sequence.
\in@ ... \expandafter {\in@@ #2{}{}#1}\edef \in@@
{\the \toks@ }\expandafter...
l.27 \qrcode{\myget{second}}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
)
! Incomplete \iffalse; all text was ignored after line 27.
<inserted text>
\fi
<*> test.tex
The file ended while I was skipping conditional text.
This kind of error happens when you say `\if...' and forget
the matching `\fi'. I've inserted a `\fi'; this might work.
! Emergency stop.
<*> test.tex
*** (job aborted, no legal \end found)
答案1
l3prop为此，我建议使用属性列表。对其元素的访问是完全可扩展的，因此可以在参数中使用。
\documentclass{article}
\usepackage{qrcode}
\usepackage{xparse}
\ExplSyntaxOn
\prop_new:N \l_stefan_testmap_prop
\prop_put:Nnn \l_stefan_testmap_prop {first} {blue}
\prop_put:Nnn \l_stefan_testmap_prop {second} {red}
\prop_put:Nnn \l_stefan_testmap_prop {foo.bar} {orange}
\prop_put:Nnn \l_stefan_testmap_prop {4} {violet}
\prop_put:Nnn \l_stefan_testmap_prop {bla} {green}
\prop_put:Nnn \l_stefan_testmap_prop {6} {violet}
\prop_put:Nnn \l_stefan_testmap_prop {7} {violet}
\prop_put:Nnn \l_stefan_testmap_prop {8} {black}
\DeclareExpandableDocumentCommand \myget { m }
{
\prop_item:Nn \l_stefan_testmap_prop { #1 }
}
\ExplSyntaxOff
\begin{document}
\qrcode{\myget{second}}
\end{document}
答案2
您需要一些可扩展的宏。顺便说一下，\protectMWE 中的 不应该在那里。它没有任何效果，如果用正确的 替换\protected它，它会产生内部不可用的效果\qrcode \myget。
\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{qrcode}
\usepackage{xinttools}
\xintForpair #1#2 in {
(first, blue),
(second, red),
(foo.bar, orange),
(4, violet),
(bla, green),
(6, violet),
(7, violet),
(8, black)
}\do {\expandafter\def\csname Testmap_#1\endcsname {#2}}
\def\myget #1{\csname Testmap_\xintZapSpaces{#1}\endcsname}
\begin{document}
\textcolor{\myget{first}}{\qrcode{\myget{first}}} %%%% ok
\textcolor{\myget{second}}{\qrcode{\myget{second}}} %%%% ok
\end{document}
