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#' Extract first matched group from a string.
#'
#' Vectorised over \code{string}. \code{pattern} should be a single pattern,
#' i.e. a character vector of length one.
#'
#' @inheritParams str_detect
#' @param pattern pattern to look for, as defined by a POSIX regular
#' expression. Pattern should contain groups, defined by (). See the
#' ``Extended Regular Expressions'' section of \code{\link{regex}} for
#' details.
#' @return character matrix. First column is the complete match, followed by
#' one for each capture group
#' @keywords character
#' @export
#' @examples
#' strings <- c(" 219 733 8965", "329-293-8753 ", "banana", "595 794 7569",
#' "387 287 6718", "apple", "233.398.9187 ", "482 952 3315",
#' "239 923 8115", "842 566 4692", "Work: 579-499-7527", "$1000",
#' "Home: 543.355.3679")
#' phone <- "([2-9][0-9]{2})[- .]([0-9]{3})[- .]([0-9]{4})"
#'
#' str_extract(strings, phone)
#' str_match(strings, phone)
str_match <- function(string, pattern) {
string <- check_string(string)
pattern <- check_pattern(pattern, string)
if (length(string) == 0) return(character())
matcher <- re_call("regexec", string, pattern)
matches <- regmatches(string, matcher)
# Figure out how many groups there are and coerce into a matrix with
# nmatches + 1 columns
tmp <- str_replace_all(pattern, "\\\\\\(", "")
n <- str_length(str_replace_all(tmp, "[^(]", "")) + 1
len <- vapply(matches, length, integer(1))
matches[len == 0] <- rep(list(rep(NA_character_, n)), sum(len == 0))
do.call("rbind", matches)
}
#' Extract all matched groups from a string.
#'
#' Vectorised over \code{string}. \code{pattern} should be a single pattern,
#' i.e. a character vector of length one.
#'
#' @inheritParams str_detect
#' @param pattern pattern to look for, as defined by a POSIX regular
#' expression. Pattern should contain groups, defined by (). See the
#' ``Extended Regular Expressions'' section of \code{\link{regex}} for
#' details.
#' @return list of character matrices, as given by \code{\link{str_match}}
#' @keywords character
#' @export
#' @examples
#' strings <- c("Home: 219 733 8965. Work: 229-293-8753 ",
#' "banana pear apple", "595 794 7569 / 387 287 6718")
#' phone <- "([2-9][0-9]{2})[- .]([0-9]{3})[- .]([0-9]{4})"
#'
#' str_extract_all(strings, phone)
#' str_match_all(strings, phone)
str_match_all <- function(string, pattern) {
matches <- str_extract_all(string, pattern)
lapply(matches, function(match) {
str_match(match, pattern)
})
}
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