R/rematch.R

In waldo: Find Differences Between R Objects

# Source copied from rematch2::re_match, but doesn't return tibble.
re_match <- function(text, pattern, perl = TRUE, ...) {
  stopifnot(is.character(pattern), length(pattern) == 1, !is.na(pattern))
  text <- as.character(text)
  match <- regexpr(pattern, text, perl = perl, ...)
  start <- as.vector(match)
  length <- attr(match, "match.length")
  end <- start + length - 1L
  matchstr <- substring(text, start, end)
  matchstr[start == -1] <- NA_character_
  res <- data.frame(.text = text, .match = matchstr)
  if (!is.null(attr(match, "capture.start"))) {
    gstart <- attr(match, "capture.start")
    glength <- attr(match, "capture.length")
    gend <- gstart + glength - 1L
    groupstr <- substring(text, gstart, gend)
    groupstr[gstart == -1] <- NA_character_
    dim(groupstr) <- dim(gstart)
    res <- cbind(groupstr, res)
  }
  names(res) <- c(attr(match, "capture.names"), ".text", ".match")
  res
}