% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/length.R
\name{stri_width}
\alias{stri_width}
\title{Determine the Width of Code Points}
\usage{
stri_width(str)
}
\arguments{
\item{str}{character vector or an object coercible to}
}
\value{
Returns an integer vector of the same length as \code{str}.
}
\description{
Approximates the number of text columns the `cat()` function
should use to print a string with a mono-spaced font.
}
\details{
The Unicode standard does not formalize the notion of a character
width. Roughly based on \url{http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c}
and the UAX #11 we proceed as follows.
The following code points are of width 0:
\itemize{
\item code points with general category (see \link{stringi-search-charclass})
\code{Me}, \code{Mn}, and \code{Cf}),
\item \code{C0} and \code{C1} control codes (general category \code{Cc})
- for compatibility with the \code{\link{nchar}} function,
\item Hangul Jamo medial vowels and final consonants
(code points with enumerable property \code{UCHAR_HANGUL_SYLLABLE_TYPE}
equal to \code{U_HST_VOWEL_JAMO} or \code{U_HST_TRAILING_JAMO};
note that applying the NFC normalization with \code{\link{stri_trans_nfc}}
is encouraged),
\item ZERO WIDTH SPACE (U+200B),
}
Characters with the \code{UCHAR_EAST_ASIAN_WIDTH} enumerable property
equal to \code{U_EA_FULLWIDTH} or \code{U_EA_WIDE} are
of width 2.
SOFT HYPHEN (U+00AD) (for compatibility with \code{\link{nchar}})
as well as any other characters have width 1.
}
\examples{
stri_width(LETTERS[1:5])
stri_width(stri_trans_nfkd("\u0105"))
stri_width( # Full-width equivalents of ASCII characters:
   stri_enc_fromutf32(as.list(c(0x3000, 0xFF01:0xFF5E)))
)
stri_width(stri_trans_nfkd("\ubc1f")) # includes Hangul Jamo medial vowels and final consonants
}
\references{
\emph{East Asian Width} -- Unicode Standard Annex #11,
\url{http://www.unicode.org/reports/tr11/}
}
\seealso{
Other length: 
\code{\link{stri_isempty}()},
\code{\link{stri_length}()},
\code{\link{stri_numbytes}()}
}
\concept{length}
