我正在尝试使用堆栈数据结构(如此处所述:推送/弹出或者保存长度/尺寸?)来存储一组 tikzmark 节点名称的各种名称(如在tikzmark
手动的) 散布在我的文本之中。
单独的堆栈实现(WE1)和\tikzmark
(WE2)运行完美,但它们的组合行为不知何故与多个错误发生冲突。
当我尝试将弹出的堆栈数据元素作为节点名称传递到命令中时(下面的 MWE),我无论如何也想不出出了什么问题\tikzmark
。这是由于我的 LaTeX 代码没有立即评估 \pop 命令而引起的问题吗(我尝试过\expandafter
但\edef
没有成功……)?我也尝试过传递\pop{\latexstack}
给 a \newcommand{}
,但我也没有设法让该方法起作用……
平均能量损失[不正确的组合行为...]
\documentclass{article}
\usepackage{blindtext, tikz}
\newtoks\latexstack
\latexstack={\empty}
\def\push#1#2{
\begingroup
\toks0={{#1}}
\edef\act{\endgroup\global#2={\the\toks0 \the#2}}\act
}
\def\pop#1{
\begingroup
\edef\act{\endgroup\noexpand\SplitOff\the#1(tail)#1}\act
}
\def\SplitOff#1#2(tail)#3{
\ifx#1\empty
\errhelp{Attempting to pop empty stack #3.}
\errmessage{You can't pop an empty stack.}
\else
#1\global#3={#2}
\fi
}
\newcommand\tikzmark[1]{\tikz[overlay,remember picture] \node(#1) {};}
\begin{document}
\push{A1}{\latexstack}
\push{B2}{\latexstack}
\blindtext \tikzmark{\pop{\latexstack}}\\
\blindtext \tikzmark{\pop{\latexstack}}\\
\begin{tikzpicture}[remember picture,overlay,scale=0.5]
\draw[red] (A) -- (B);
\end{tikzpicture}
\end{document}
WE1[堆栈数据结构的正确行为:A1、B2、C3 和 D4 被推送并按顺序从数据结构中弹出]
\documentclass{article}
\newtoks\latexstack
\latexstack={\empty}
\def\push#1#2{
\begingroup
\toks0={{#1}}
\edef\act{\endgroup\global#2={\the\toks0 \the#2}}\act
}
\def\pop#1{
\begingroup
\edef\act{\endgroup\noexpand\SplitOff\the#1(tail)#1}\act
}
\def\SplitOff#1#2(tail)#3{
\ifx#1\empty
\errhelp{Attempting to pop empty stack #3.}
\errmessage{You can't pop an empty stack.}
\else
#1\global#3={#2}
\fi
}
\begin{document}
\push{A1}{\latexstack}
\push{B2}{\latexstack}
\push{C3}{\latexstack}
\push{D4}{\latexstack}
\pop{\latexstack},\\
\pop{\latexstack},\\
\pop{\latexstack},\\
\pop{\latexstack}.
\end{document}
WE2[正确做法\tikzmark
:点 A 和 B 被标记,并用红线连接在一起]
\documentclass{article}
\usepackage{blindtext, tikz}
\newcommand\tikzmark[1]{\tikz[overlay,remember picture] \node(#1) {};}
\begin{document}
\blindtext \tikzmark{A}\\
\blindtext \tikzmark{B}
\begin{tikzpicture}[remember picture,overlay,scale=0.5]
\draw[red] (A) -- (B);
\end{tikzpicture}
\end{document}
答案1
我认为这里的问题是扩展。当 TikZ 创建节点时,节点名称使用 完全扩展\edef
。
假设原始代码如下,请考虑以下内容
\push{A1}{\latexstack}
\push{B2}{\latexstack}
\edef\nodename{\pop{\latexstack}}
\show\nodename
这说明了完整的扩展并将给出(在日志文件中):
! Undefined control sequence.
\pop #1^^@- \begingroup \edef \act
{\endgroup \noexpand \SplitOff \the #1(tail...
l.36 \edef\nodename{\pop{\latexstack}
}
! Undefined control sequence.
\pop ... \noexpand \SplitOff \the #1(tail)#1}\act
l.36 \edef\nodename{\pop{\latexstack}
}
> \nodename=macro:
-> \begingroup \edef {\endgroup \SplitOff {B2}{A1}\empty (tail)\latexstack }.
l.37 \show\nodename
注意问题是不是这是未定义的。如果放置在序言中的某个位置,\act
错误将消失,但 的内容仍然是一大堆 LaTeX 代码,而不是所需的节点名称。\let\act=\relax
\nodename
一个解决方案是使用一个\popto
命令将堆栈顶部的值弹出到一个宏中,然后将其用作节点名(注意:我还重新实现了该\push
宏):
\def\push#1#2{%
\def\tmp{{#1}}%
\expandafter\expandafter\expandafter%
#2\expandafter\expandafter\expandafter{\expandafter\tmp\the#2}%
\ignorespaces}
\def\popto#1#2{%
\expandafter\SplitOffTo\the#1\stop{#1}{#2}%
}
\def\SplitOffTo#1#2\stop#3#4{%
\def\tmp{#1}%
\ifx\tmp\empty%
\errhelp{Attempting to pop empty stack #3.}%
\errmessage{You can't pop an empty stack.}%
\else%
\def#4{#1}\global#3={#2}%
\fi%
}
可以像这样使用:
\newtoks\latexstack
\latexstack={\empty}
\push{A1}{\latexstack}
\push{B2}{\latexstack}
\popto{\latexstack}{\nodename}
\tikzmark{\nodename}
\show\nodename
Some text \tikzmark{\nodename}
\popto{\latexstack}{\nodename}
\tikzmark{\nodename}
\show\nodename
Some more text \tikzmark{\nodename}
日志文件将显示(类似)以下内容:
> \nodename=macro:
->B2.
l.31 \show\nodename
> \nodename=macro:
->A1.
l.34 \show\nodename
如果所有这些看起来有点麻烦,那么这些\popto
东西可以被绑定在\tikzmarkpop
宏中:
\documentclass[border=5]{standalone}
\usepackage{tikz}
\def\push#1#2{%
\def\tmp{{#1}}%
\expandafter\expandafter\expandafter%
#2\expandafter\expandafter\expandafter{\expandafter\tmp\the#2}%
\ignorespaces}
\def\popto#1#2{%
\expandafter\SplitOffTo\the#1\stop{#1}{#2}%
}
\def\SplitOffTo#1#2\stop#3#4{%
\def\tmp{#1}
\ifx\tmp\empty%
\errhelp{Attempting to pop empty stack #3.}%
\errmessage{You can't pop an empty stack.}%
\else%
\def#4{#1}\global#3={#2}%
\fi}
\def\tikzmarkpop#1{%
\popto{#1}{\nodename}%
\tikz[remember picture, overlay]\coordinate(\nodename);}
\newtoks\latexstack
\latexstack={\empty}
\begin{document}
\push{A1}{\latexstack}
\push{B2}{\latexstack}
Some text\tikzmarkpop{\latexstack}
Some more text\tikzmarkpop{\latexstack}
\begin{tikzpicture}[remember picture, overlay]
\draw [red, <->] (A1) -- (B2);
\end{tikzpicture}
\end{document}