1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
#' Construct an missing xml object
#' @export
#' @keywords internal
xml_missing <- function() {
out <- list()
class(out) <- "xml_missing"
out
}
format.xml_missing <- function(x, ...) {
"<NA>"
}
#' @export
print.xml_missing <- function(x, width = getOption("width"), max_n = 20, ...) {
cat("{xml_missing}\n")
cat(format(x), "\n", sep = "")
}
#' @export
as.character.xml_missing <- function(x, ...) {
NA_character_
}
# These mimic the behavior of NA[[1]], NA[[2]], NA[1], NA[2]
#' @export
`[.xml_missing` <- function(x, i, ...) x
#' @export
`[[.xml_missing` <- function(x, i, ...) if (i == 1L) x else cli::cli_abort("subscript out of bounds")
#' @export
is.na.xml_missing <- function(x) {
TRUE
}
|
