R/utils.R

In charr: String Processing Reimagined for 'ALTREP' Strings

check_lengths <- function(
  string,
  pattern,
  replacement = NULL,
  error_call = caller_env()
) {
  # stringi already correctly recycles vectors of length 0 and 1
  # we just want more stringent vctrs checks for other lengths
  vctrs::vec_size_common(
    string = string,
    pattern = pattern,
    replacement = replacement,
    .call = error_call
  )
}

no_boundary <- function(call = caller_env()) {
  cli::cli_abort(tr_("{.arg pattern} can't be a boundary."), call = call)
}
no_empty <- function(call = caller_env()) {
  cli::cli_abort(
    tr_("{.arg pattern} can't be the empty string ({.code \"\"})."),
    call = call
  )
}

tr_ <- function(...) {
  enc2utf8(gettext(paste0(...), domain = "R-charr"))
}

# copy names from `string` to output, regardless of output type
copy_names <- function(from, to) {
  nm <- names(from)
  if (is.null(nm)) {
    return(to)
  }

  if (is.matrix(to)) {
    rownames(to) <- nm
    to
  } else {
    set_names(to, nm)
  }
}

# keep names if pattern is scalar (i.e. vectorised) or same length as string.
keep_names <- function(string, pattern) {
  length(pattern) == 1L || length(pattern) == length(string)
}

preserve_names_if_possible <- function(string, pattern, out) {
  if (keep_names(string, pattern)) {
    copy_names(string, out)
  } else {
    out
  }
}