\emph and punctuation

Question

I know \emph is to be used to emphasize text. However once in a while, a punctuation mark follows emphasized text, mostly commas and periods. When \emph makes text italic, it should extend to the punctuation mark, but other emphasis like underlining, color, background, etc. should not.

Can I have a solution in the preamble that defines \emph such that it extends to punctuation marks which follow the text?

I.e. I want

This is a \emph{small}, simple example.

to be rendered as

This is a small, simple example.

and not to become

This is a small, simple example.

@CarLaTeX I think the OP would like a generic way to redefine \emph{} such that it emphasises text by means of italicisation and, say, colouring it red, but, if say the emphasised text is followed by punctuation, the punctuation should also be italicised, but not coloured red. So, \emph{small,} could be used to make small red and italic and the comma italic, but not red. But I think the OP wants generic solutions that could include many types of emphasis, but only the italicisation would extend to punctuation — Au101, Jan 03 '17 at 21:36
@CarLaTeX It's alright, actually perhaps the OP could clarify a little bit? I was confused too. Re-reading it, seems that the OP is using \emph{} for italicisation, and then, say, nesting other emphasis, so like \emph{\textcolor{red}{small}}, and it seems like they would like the \emph alone to extend to any punctuation outside the braces, but nothing else, which it seems is how they would like to try to achieve their desired result. I'm not sure that would be the best approach though — Au101, Jan 03 '17 at 21:43

score 6 · Accepted Answer · 2017-01-08T05:52:01.280

6

\documentclass{article}

\usepackage{xspace}
\let\Emph\emph
\makeatletter
\def\emph#1{%
  \@ifnextchar,{\@emph@i#1}{%
    \@ifnextchar;{\@emph@ii#1}{%
      \@ifnextchar.{\@emph@iii#1}{%
        \@ifnextchar!{\@emph@iv#1}{\Emph{#1}\xspace}}}}}
\def\@emph@i#1,{\Emph{#1,}\xspace}
\def\@emph@ii#1;{\Emph{#1;}\xspace}
\def\@emph@iii#1.{\Emph{#1.}\xspace}
\def\@emph@iv#1!{\Emph{#1!}\xspace}
\makeatother
\begin{document}

    This is a \emph{small}, simple example.\par
    This is a \emph{small,} simple example.\par
    This is a \emph{small}; simple example.\par
    This is a \emph{small;} simple example.\par
    This is a \emph{small}. simple example.\par
    This is a \emph{small.} simple example.\par
    This is a \emph{small}! simple example.\par
    This is a \emph{small!} simple example.

\end{document}

edited Jan 08 '17 at 05:52

answered Jan 03 '17 at 21:49

The answer is great and helpful, but only solves the problem partly. I tried to expand the solution to consider other punctuation as well, but \def\@emph#1,{...} seems not to work with more than one punctuation mark. – Bolpat Jan 06 '17 at 20:14
it is chain of \@ifnextchar,{..}{\@ifnextchar.{..}{\@ifnextchar;{}{}}}} – Jan 06 '17 at 20:38
I tried that. The problem is extending \def\@emph#1,{\Emph{#1,}\xspace}. I couldn't figure out how to that. Something like overloading didn't work; I tried \def\@emph#1,{\Emph{#1,}\xspace} \def\@emph#1.{\Emph{#1.}\xspace}. I also tried \def\@emph#1#2{\Emph{#1#2}\xspace}, but that matches just two letters. I suspect I cannot restrict #2 to match punctuation? – Bolpat Jan 08 '17 at 04:06
see edited answer. Can easily be extended – Jan 08 '17 at 05:52
Usual caveat: doing \let\x\y when \y has been defined with \DeclareRobustCommand (like \emph) is dangerous and \LetLtxMacro should be employed; see When to use \LetLtxMacro – egreg Jan 08 '17 at 09:11

\emph and punctuation

1 Answers1