https://github.com/cran/pracma
Tip revision: 71455748623ef69836470c75c5f9384f6e872d45 authored by HwB on 28 June 2011, 00:00:00 UTC
version 0.6-3
version 0.6-3
Tip revision: 7145574
regexp.Rd
\name{regexp}
\alias{regexp}
\alias{regexpi}
\title{
Match regular expression
}
\description{
Returns the positions of substrings that match the regular expression.
}
\usage{
regexp(s, pat, ignorecase = FALSE, once = FALSE, split = FALSE)
regexpi(s, pat, once = FALSE, split = FALSE)
}
\arguments{
\item{s}{Character string, i.e. of length 1.}
\item{pat}{Matching pattern as character string.}
\item{ignorecase}{Logical: whether case should be ignored;
default: \code{FALSE}.}
\item{once}{Logical: whether the first are all occurrences should be found;
default: all.}
\item{split}{Logical: should the string be splitted at the occurrences of
the pattern?; default: no.}
}
\details{
Returns the start and end positions and the exact value of substrings
that match the regular expression. If \code{split} is choosen, the
splitted strings will also be returned.
}
\value{
A list with components \code{start} and \code{end} as numeric vectors
indicating the start and end positions of the matches.
\code{match} contains each exact match, and \code{split} contains the
character vector of splitted strings.
If no match is found all components will be \code{NULL}, except
\code{split} that will contain the whole string if \code{split = TRUE}.
}
\note{
This is the behavior of the corresponding Matlab function, though the
signature, options and return values do not match exactly.
Notice the transposed parameters \code{s} and \code{pat} compared to the
corresponding R function \code{regexpr}.
}
\seealso{
\code{\link{regexpr}}
}
\examples{
s <- "bat cat can car COAT court cut ct CAT-scan"
pat <- 'c[aeiou]+t'
regexp(s, pat)
regexpi(s, pat)
}
\keyword{ string }