添加

Question

我正在尝试排版一本旧书，我注意到其中的所有数字都用 1 个点包围（除非它是一行中的第一个，在这种情况下前面没有点，或者它是一行中最后一个，在这种情况下后面没有点）。如果存在，则该点位于正常的单词间空间内（好像它本身不占用空间）。

有没有办法在（lua）TEX（我使用上下文）中以这种方式排版数字？

我尝试过非常简单的方法，但是它不会丢弃行首或行末的点，而且我猜如果胶水收缩太多也会出现问题。

\starttext

\dorecurse{100}{
Le \llap{.}1\rlap{.} element. }

\stoptext

已尝试cleaders（可丢弃）但点位于中心（并且不靠近数字）并且似乎没有像我预期的那样伸展。

添加了用于说明的图片。这显示了行尾的点被丢弃，但数字周围的间距仍然太大。

旧版印刷术示例（法语版 Olivetan 圣经，pdf 可从http://www.e-rara.ch/gep_g/content/titleinfo/1751440如果你喜欢哥特式字体。从书上很难看出间距是多少。

Answer 1

\leaders两个跳过（和非）的组合顺序\leaders并不重要：它们始终会作为一个单元消失。

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly 
                                 % declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\makeatletter

\newsavebox\@NWD@dot@box
\newlength\@NWD@space@skip
\newcommand*\numberwithdots[1]{%
    \unskip
    \setbox\@NWD@dot@box \hbox{.}% use current font
    \@NWD@space@skip
        \fontdimen\tw@ \font
        \@plus \fontdimen\thr@@ \font
        \@minus \fontdimen 4 \font
    \hskip \glueexpr \@NWD@space@skip-\wd\@NWD@dot@box
    \cleaders \copy\@NWD@dot@box \hskip \wd\@NWD@dot@box
    #1%
    \cleaders \copy\@NWD@dot@box \hskip \wd\@NWD@dot@box
    \hskip \glueexpr \@NWD@space@skip-\wd\@NWD@dot@box
    \ignorespaces
}

\makeatother



\begin{document}

\numberwithdots{1} note that the indent does \emph{not} count as a ``begin of
line'': not sure if this is what is wanted.  Some text \numberwithdots{2} that
includes \numberwithdots{3} some numbers: I~hope that \numberwithdots{4} some
\numberwithdots{5} of them will fall \numberwithdots{6} on a line boundary,
although \numberwithdots{7} it is \numberwithdots{8} always possible
\numberwithdots{9} to arrange things in order \numberwithdots{10} to make
\numberwithdots{11} this happen.  And it \numberwithdots{12} is also
possible\linebreak[4] \numberwithdots{13} to force \numberwithdots{14} a line
\numberwithdots{15} break\linebreak[4] at a specific \numberwithdots{16}
position.

Two numbers in a row, though, do not \numberwithdots{123} \numberwithdots{456} 
look well.

\end{document}

这是我得到的输出：

添加

或许，在带点的数字周围使用更宽的空间会更好；并且允许用户自定义这方面会更好。

% My standard header for TeX.SX answers:
\documentclass[a4paper]{article} % To avoid confusion, let us explicitly 
                                 % declare the paper format.

\usepackage[T1]{fontenc}         % Not always necessary, but recommended.
% End of standard header.  What follows pertains to the problem at hand.

\makeatletter

\newsavebox\@NWD@dot@box
\newlength\@NWD@space@skip
\newcommand*\@NWD@factor{1.5} % redefine default as you please
\newcommand*\numberwithdots[1]{%
    \unskip
    \setbox\@NWD@dot@box \hbox{.}% use current font
    \@NWD@space@skip
        \@NWD@factor\fontdimen\tw@ \font
        \@plus \fontdimen\thr@@ \font
        \@minus \fontdimen 4 \font
    \hskip \glueexpr \@NWD@space@skip-\wd\@NWD@dot@box
    \cleaders \copy\@NWD@dot@box \hskip \wd\@NWD@dot@box
    #1%
    \cleaders \copy\@NWD@dot@box \hskip \wd\@NWD@dot@box
    \hskip \glueexpr \@NWD@space@skip-\wd\@NWD@dot@box
    \ignorespaces
}
\newcommand*\nwdsetdotspacing[1]{\def\@NWD@factor{#1}}
\newcommand*\nwdlinebreak{\unskip\unskip\linebreak}

\makeatother



\begin{document}

\numberwithdots{1} note that the indent does \emph{not} count as a ``begin of
line'': not sure if this is what is wanted.  Some text \numberwithdots{2} that
includes \numberwithdots{3} some numbers: I~hope that \numberwithdots{4} some
\numberwithdots{5} of them will fall \numberwithdots{6} on a line boundary,
although \numberwithdots{7} it is \numberwithdots{8} always possible
\numberwithdots{9} to arrange things in order \numberwithdots{10} to make
\numberwithdots{11} this happen.  And it \numberwithdots{12} is also
possible\nwdlinebreak[4] \numberwithdots{13} to force \numberwithdots{14} a line
break \numberwithdots{15}\nwdlinebreak[4] at a specific \numberwithdots{16}
position.

Two numbers in a row, though, do not \numberwithdots{123} \numberwithdots{456} 
look well.

\nwdsetdotspacing{} % empty argument amounts to 1

\numberwithdots{1} note that the indent does \emph{not} count as a ``begin of
line'': not sure if this is what is wanted.  Some text \numberwithdots{2} that
includes \numberwithdots{3} some numbers: I~hope that \numberwithdots{4} some
\numberwithdots{5} of them will fall \numberwithdots{6} on a line boundary,
although \numberwithdots{7} it is \numberwithdots{8} always possible
\numberwithdots{9} to arrange things in order \numberwithdots{10} to make
\numberwithdots{11} this happen.  And it \numberwithdots{12} is also
possible\nwdlinebreak[4] \numberwithdots{13} to force \numberwithdots{14} a line
break \numberwithdots{15}\nwdlinebreak[4] at a specific \numberwithdots{16}
position.

\nwdsetdotspacing{2}

\numberwithdots{1} note that the indent does \emph{not} count as a ``begin of
line'': not sure if this is what is wanted.  Some text \numberwithdots{2} that
includes \numberwithdots{3} some numbers: I~hope that \numberwithdots{4} some
\numberwithdots{5} of them will fall \numberwithdots{6} on a line boundary,
although \numberwithdots{7} it is \numberwithdots{8} always possible
\numberwithdots{9} to arrange things in order \numberwithdots{10} to make
\numberwithdots{11} this happen.  And it \numberwithdots{12} is also
possible\nwdlinebreak[4] \numberwithdots{13} to force \numberwithdots{14} a line
break \numberwithdots{15}\nwdlinebreak[4] at a specific \numberwithdots{16}
position.

\end{document}

不幸的是，由于技术原因，为了强制换行，我们还必须\linebreak用我们的命令替换该命令\nwdlinebreak。

输出：

额外的自由度：也是退格量的一个因素。除此之外，以下代码摘录提供了另一种更强大的实现方式：

\makeatletter

% Alternative approach that permits nesting: use temporaries, but with grouping:
\newcommand*\@NWD@dot@factor{}
\newcommand*\@NWD@spc@factor{1.5}
\newcommand*\numberwithdots[1]{%
    \unskip
    \setbox\z@ \hbox{.}% use current font
    \dimen@ \@NWD@dot@factor\wd\z@
    \skip@
        \@NWD@spc@factor\fontdimen\tw@ \font
        \@plus \fontdimen\thr@@ \font
        \@minus \fontdimen 4 \font
    % More elegant with subroutines (or perhaps not):
    \@NWD@nonleader@hskip \@NWD@leader@hskip
    {#1}%
    \@NWD@leader@hskip \@NWD@nonleader@hskip
    \ignorespaces
}
\newcommand*\@NWD@nonleader@hskip{%
    \hskip \glueexpr \skip@-\dimen@ \relax % for robustness
}
\newcommand*\@NWD@leader@hskip{%
    \cleaders \copy\z@ \hskip \wd\z@
}
\newcommand*\nwdsetdotspacing[2][]{%
    \def\@NWD@dot@factor{#1}%
    \def\@NWD@spc@factor{#2}%
}
\newcommand*\nwdlinebreak{\unskip\unskip\linebreak}

\makeatother

---

进一步阅读

将方框放入一团胶水中\leaders，以便使其在换行符或分页符处消失，这种技巧众所周知：据我所知，它是由 Marcin Woliński 于 2007 年首次提出的，请参阅如何让换行符处的框消失。

也可以看看：

• 检查是否在一行的开头；

• 某个内容是页面上的第一项吗？；

• 是否可以重新定义空白命令？。

Answer 2

\input expl3-generic % just for not using ConTeXt

\ExplSyntaxOn
\cs_set_eq:NN \dorecurse \prg_replicate:nn
\ExplSyntaxOff

\def\num#1{\unskip\adddot#1\adddot\ignorespaces}
\def\adddot{%
  \cleaders\hbox to 1.5\dimexpr\fontdimen2\font-\fontdimen4\font\relax{\hss.\hss}%
  \hskip1.5\fontdimen2\font plus \fontdimen3\font minus \fontdimen4\font
}

\dorecurse{100}{The \num{2} element \num{2} xy. }

\bye

如果将句点附加到数字上，那就更简单了。

\input expl3-generic

\ExplSyntaxOn
\cs_set_eq:NN \dorecurse \prg_replicate:nn
\ExplSyntaxOff

\newbox\periodbox

\def\num#1{\leavevmode\addleftdot#1\addrightdot}
\def\addleftdot{%
  \setbox\periodbox=\hbox{.}%
  \cleaders\copy\periodbox\hskip\wd\periodbox\relax
}
\def\addrightdot{%
  \setbox\periodbox=\hbox{.}%
  \cleaders\copy\periodbox\hskip\wd\periodbox\relax
}

\dorecurse{100}{The \num{2} element \num{2} xy. }

\bye