| sQuote {base} | R Documentation |
Single or double quote text by combining with appropriate single or double left and right quotation marks.
sQuote(x) dQuote(x)
x |
an R object, to be coerced to a character vector. |
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.
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, sQuote and dQuote provide undirectional
ASCII quotation style. In a UTF-8 locale (see
l10n_info), the Unicode directional quotes are used.
Markus Kuhn, “ASCII and Unicode quotation marks”. http://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html
Quotes for quoting R code.
shQuote for quoting OS commands.
paste("argument", sQuote("x"), "must be non-zero")