I am experiencing an odd issue with \textit and \emph. I have a list from plaintext and want to format it. Here is a minimum example demonstrating my issue:
\documentclass{article}
\begin{document}
\textit{
(a)
(b)
}
\end{document}
Results in:
Why? What is going on here?
The command \textit does not permit paragraph breaks in its argument, while all-blank lines cause paragraph breaks. You must be getting the following error message:
Runaway argument?
{ (a)
! Paragraph ended before \text@command was complete.
<to be read again>
\par
l.9 }
Any lessons to be learnt? I'd say there are 2. First, don't ignore error messages. Second, to get your code to compile and perform the expected formatting, change the code chunk to
{\itshape
(a)
(b)
}
\textit, for longer we have the switch \itshape. Same thing in html, its kinda ad practice to mark huge amounts of text inside a <em></em>, what is where we have css.
– daleif
Mar 16 '21 at 21:47
\par token, which generates a paragraph break. It so happens -- I'm afraid I can't answer the why part of your question knowledgeably -- that a particular choice was made in the design of the LaTeX commands \textit, textbf, \textsc etc: they are all not set up to tolerate paragraph breaks in their arguments. Clearly, this was a conscious design choice, not an oversight, as it applies consistently across these commands.
– Mico
Mar 16 '21 at 21:48
\emph) are designed to be used just within paragraphs, while others (usually environments) are meant to be used for longer sections of text.
– Peter LeFanu Lumsdaine
Mar 16 '21 at 22:24
\par or an empty line, which is converted to \par by TeX), but short arguments may not contain paragraph ends. Most explanations for that behaviour I have seen are about error detection: Many macros should only apply to a short stretch of text and not to whole paragraphs, so when the macro encounters a paragraph end, the user probably forgot a } to close the argument. ...
– moewe
Mar 17 '21 at 07:44
\textit and \emph are defined as taking short arguments, so they will throw an error at the end of a paragraph. Presumably the idea is that \textit should be used to highlight short passages of text within a single paragraph and that you should be using the switch \itshape (possibly wrapped up in an environment definition) to typeset long passages of text spanning several paragraphs in italics.
– moewe
Mar 17 '21 at 07:49
\text<..> commands are set up the way they are, i.e., that they're designed not to accept \par tokens in their arguments. I was reluctant to write that up as I wasn't sure whether my recollections were suffiiciently on target.
– Mico
Mar 17 '21 at 09:22
\textitmust not contain an empty line or paragraph break. If you want to format more text, use{\itshape (a) \par (b)}. But LaTeX has better ways to produce lists (enumerate). – moewe Mar 16 '21 at 07:30\itshapedes not wok in mathmode, which would cause him further problems. – Roland Mar 16 '21 at 07:57\textitallows line breaks with commands such as double backslash or\newline. So I think you could do it with\textitas well. – Roland Mar 16 '21 at 08:09\\and\newlineare not the same as an empty line or\par. It is a good rule of thumb that one should not use\\or\newlinein the normal text body of a document: Paragraphs should be ended with an empty line (or\parif that is more convenient or appropriate) and within paragraphs there should be no forced line breaks with\\. (Of course\\has its use inalignor table environments and might be useful occasionally to avoid a bad line break. @Roland) – moewe Mar 16 '21 at 16:47