\HeaderA{sQuote}{Quote Text}{sQuote}
\aliasA{dQuote}{sQuote}{dQuote}
\keyword{character}{sQuote}
\begin{Description}\relax
Single or double quote text by combining with appropriate single or
double left and right quotation marks.
\end{Description}
\begin{Usage}
\begin{verbatim}
sQuote(x)
dQuote(x)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] an \R{} object, to be coerced to a character vector.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The purpose of the functions is to provide a simple means of markup
for quoting text to be used in the R output, e.g., in warnings or
error messages.  Note that English quoting conventions are used,
whatever the locale in use.

The choice of the appropriate quotation marks depends on both the
locale and the available character sets.  Older Unix/X11 fonts
displayed the grave accent (0x60) and the apostrophe (0x27) in a way
that they could also be used as matching open and close single
quotation marks.  Using modern fonts, or non-Unix systems, these
characters no longer produce matching glyphs.  Unicode provides left
and right single quotation mark characters (U+2018 and U+2019); if
Unicode cannot be assumed, it seems reasonable to use the apostrophe
as an undirectional single quotation mark.

Similarly, Unicode has left and right double quotation mark characters
(U+201C and U+201D); if only ASCII's typewriter characteristics can be
employed, than the ASCII quotation mark (0x22) should be used as both
the left and right double quotation mark.

By default, \code{sQuote} and \code{dQuote} employ undirectional 
ASCII quotation style.  In a UTF-8 locale (see \code{\LinkA{l10n\_info}{l10n.Rul.info}}),
the Unicode directional quotes are used.
\end{Details}
\begin{References}\relax
Markus Kuhn, \dQuote{ASCII and Unicode quotation marks}.
\url{http://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html}
\end{References}
\begin{SeeAlso}\relax
\code{Quotes} for quoting \R{} code.

\code{\LinkA{shQuote}{shQuote}} for quoting OS commands.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
paste("argument", sQuote("x"), "must be non-zero")
\end{ExampleCode}
\end{Examples}

