encodeString: Encode Character Vector as for Printing

Description

encodeString escapes the strings in a character vector in the same way print.default does, and optionally fits the encoded strings within a field width.

Usage

encodeString(x, width = 0, quote = "", na.encode = TRUE,
             justify = c("left", "right", "centre", "none"))

Arguments

A character vector, or an object that can be coerced to one by as.character.

width

integer: the minimum field width. If NULL or NA, this is taken to be the largest field width needed for any element of x.

quote

character: quoting character, if any.

na.encode

logical: should NA strings be encoded?

justify

character: partial matches are allowed. If padding to the minimum field width is needed, how should spaces be inserted? justify == "none" is equivalent to width = 0, for consistency with format.default.

Value

A character vector of the same length as x, with the same attributes (including names and dimensions) but with no class set.
As from R3.0.0, marked UTF-8 encodings are preserved.

Details

This escapes backslash and the control characters \a (bell), \b (backspace), \f (formfeed), \n (line feed), \r (carriage return), \t (tab) and \v (vertical tab) as well as any non-printable characters in a single-byte locale, which are printed in octal notation (\xyz with leading zeroes).

Which characters are non-printable depends on the current locale. Windows' reporting of printable characters is unreliable, so there all other control characters are regarded as non-printable, and all characters with codes 32--255 as printable in a single-byte locale. See print.default for how non-printable characters are handled in multi-byte locales.

If quote is a single or double quote any embedded quote of the same type is escaped. Note that justification is of the quoted string, hence spaces are added outside the quotes.

Examples

Run this code

x <- "abbc
def"
print(x)
cat(x) # interprets escapes
cat(encodeString(x), "", sep = "") # similar to print()

factor(x) # makes use of this to print the levels

x <- c("a", "ab", "abcde")
encodeString(x) # width = 0: use as little as possible
encodeString(x, 2) # use two or more (left justified)
encodeString(x, width = NA) # left justification
encodeString(x, width = NA, justify = "c")
encodeString(x, width = NA, justify = "r")
encodeString(x, width = NA, quote = "'", justify = "r")