![\edef\x 技巧和 pgfmath](https://linux22.com/image/311150/%5Cedef%5Cx%20%E6%8A%80%E5%B7%A7%E5%92%8C%20pgfmath.png)
使用下面的 MWE,我发现了以下问题:在 figure* 环境中,我有三个不同的 \lstset 指令。第一个和第三个(注释掉的)有效,第二个(原样)显示错误消息“语言 [ANSI]C 未定义”。错误消息中的语言名称似乎很完美。如果我使用 \edef 技巧,错误就会消失。我想知道为什么在行中
\begingroup\edef\x{\endgroup\noexpand\lstset{language={\ME@language}}}\x
我确实需要 \edef,为什么后面 3 行
> \ME@decorations % Decorating comments
如果我按照与此行中的 \ME@language 相同的方式处理它,则会失败
\documentclass{book}
\usepackage{xcolor}
\usepackage{xkeyval}
\usepackage{listings}
\usepackage{tikz}
\usetikzlibrary{
shapes,
positioning,
arrows,
fit,
backgrounds,
calc,
tikzmark,
shadows,
}
\definecolor{ForestGreen}{rgb}{0.0, 0.4, 0.0}
\definecolor{burntorange}{rgb}{0.8, 0.33, 0.0}
\newlength{\mywidth} % Used in defining listing width
\definecolor{ivory}{rgb}{1.0, 1.0, 0.94}
\colorlet{SeparatorColor}{burntorange}
\makeatletter
\define@key{MEMacros}{decorations}{\def\ME@decorations{#1}}
\define@key{MEMacros}{language}{\def\ME@language{#1}}
\define@key{MEMacros}{number}{\def\ME@number{#1}}
\presetkeys{MEMacros}{number=1}{}%
\makeatother
%%Usage \MESourceFile[keys]{source file}{caption}{label}
\makeatletter
\newcommand\MESourceFile[4][]{%
\setkeys{MEMacros}{%
language={[ANSI]C},%
decorations={},%
#1%
}%
\begin{figure*}[h!btp]
% \lstset{language={[ANSI]C}}
\lstset{language={\ME@language}}
% \begingroup\edef\x{\endgroup\noexpand\lstset{language={\ME@language}}}\x
\caption{#3}
\lstinputlisting[label=#4, name=#4]{#2}%
\ME@decorations % Decorating comments
\end{figure*}
}
%% Prepare for some decorations on the listing files
\newif\iflst@linemark
\lst@AddToHook{EveryLine}{%
\begingroup
\advance\c@lstnumber by \@ne
\pgfmark{line-\lst@name-\the\c@lstnumber-start}%
\endgroup
}
\lst@AddToHook{EOL}{%
\pgfmark{line-\lst@name-\the\c@lstnumber-end}%
\global\lst@linemarktrue
}
\lst@AddToHook{OutputBox}{%
\iflst@linemark
\pgfmark{line-\lst@name-\the\c@lstnumber-first}%
\global\lst@linemarkfalse
\fi
}
\def\tkzlst@fnum#1\relax#2\@STOP{%
\def\@test{#2}%
\ifx\@test\@empty
\def\tkzlst@start{0}%
\else
\@tempcnta=#1\relax
\advance\@tempcnta by \m@ne
\def\tkzlst@start{\the\@tempcnta}%
\fi
}
\lst@AddToHook{Init}{%
\expandafter\tkzlst@fnum\lst@firstnumber\relax\@STOP
\pgfmark{line-\lst@name-\tkzlst@start-start}%
}
%% Put a balloon around some lines in a source
% Usage: \MEHighlightLines{BallonName}{SourceName}{FirstLine}{LastLine}
\newcommand\MEHighlightLines[4]{%
\pgfmathtruncatemacro\pgf@temp{#3-1}%
\iftikzmark{line-#2-\pgf@temp-start}
{%
\iftikzmark{line-#2-#3-first}
{%
\xdef\b@lines{({pic cs:line-#2-\pgf@temp-start} -| {pic cs:line-#2-#3-first})}%
}
{%
\iftikzmark{line-#2-#3-start}
{%
\xdef\b@lines{({pic cs:line-#2-\pgf@temp-start} -| {pic cs:line-#2-#3-start})}%
}
{%
\xdef\b@lines{(pic cs:line-#2-\pgf@temp-start)}
}%
}%
}
{%
\xdef\b@lines{}%
}%
\foreach \k in {#3,...,#4} {%
\iftikzmark{line-#2-\k-first}
{%
\xdef\b@lines{\b@lines (pic cs:line-#2-\k-first) }
}
{}%
\iftikzmark{line-#2-\k-end}
{%
\xdef\b@lines{\b@lines (pic cs:line-#2-\k-end) }
}
{}%
}%
\ifx\b@lines\pgfutil@empty
\else
\edef\pgf@temp{%
\noexpand\tikz[remember picture,overlay]
\noexpand\node[
fit={\b@lines}, color=ForestGreen,yshift=-2pt,
draw, fill=green!30, opacity=0.4, inner sep=1pt, rounded corners=5pt
] (#1) {};
}%
\pgf@temp
\fi
}
\makeatother
\begin{document}
\MESourceFile[%
decorations={
\MEHighlightLines{HelloWorldsystem}{lst:HelloWorld.c}{1}{3}
}%
]{HelloWorld.c}{Hello world}{lst:HelloWorld.c}
\end{document}
#include <stdio.h>
int main()
{
printf("hello, world\n");
}
答案1
当你说
\lstset{
language=<whatever>,
}
TeX 不会扩展任何宏,<whatever>
而是listings
将其结果与已知语言列表进行比较。在<whatever>
的情况下\ME@language
,它是不是在列表中。
然而,如果你这样做
\begingroup\edef\x{\endgroup\noexpand\lstset{language={\ME@language}}}\x
TeX 最终会
\lstset{language=[ANSI]C}
并且listings
会很高兴。
检测到未知语言的神秘错误信息具有欺骗性,因为它listings
会传递\ME@language
给错误显示命令,该命令会在发出消息时将其展开。