答案1
考虑示例文件
\hsize=70pt a shelf{}ful firefly
\hsize=70pt shelf{}ful firefly
\end
在其上运行 TeX 后,我们进入终端
Overfull \hbox (7.58342pt too wide) in paragraph at lines 1--2
[]\tenrm a shelf-ful fire-|
Overfull \hbox (0.63898pt too wide) in paragraph at lines 3--4
[]\tenrm shelfful fire-|
您可以注意到,在第二种情况下,符号表示有所不同,原因是 TeX 从不尝试对前面没有粘连符的单词片段进行连字。LuaTeX 中没有使用此限制,事实上,如果我们在同一文件上运行 LuaTeX,我们会得到
Overfull \hbox (7.58342pt too wide) in paragraph at lines 1--2
[]\tenrm a shelf-ful fire-|
Overfull \hbox (0.36119pt too wide) in paragraph at lines 3--4
[]\tenrm shelf-ful fire-|
一旦对单词片段进行了试验性连字,就会重新构成连字。TeXbook 确实建议使用斜体校正\/
或其他显式字距调整来断开连字。对于ff
,\kern0pt
Computer Modern 似乎效果最好,但其他字体可能并非如此。