#' Converting vectors to data frames, and vice versa

#'

#' @description

#' `enframe()` converts named atomic vectors or lists to one- or two-column

#' data frames.

#' For a list, the result will be a nested tibble with a column of type `list`.

#' For unnamed vectors, the natural sequence is used as name column.

#'

#' @param x A vector (for `enframe()`) or a data frame with one or two columns

#' (for `deframe()`).

#' @param name,value Names of the columns that store the names and values.

#' If `name` is `NULL`, a one-column tibble is returned; `value` cannot be `NULL`.

#'

#' @return For `enframe()`, a [tibble] with two columns (if `name` is not `NULL`, the default)

#' or one column (otherwise).

#' @export

#'

#' @examples

#' enframe(1:3)

#' enframe(c(a = 5, b = 7))

#' enframe(list(one = 1, two = 2:3, three = 4:6))

enframe <- function(x, name = "name", value = "value") {

if (is.null(value)) {

abort_enframe_value_null()

}

if (is.null(x)) {

x <- logical()

}

# FIXME: Enable again for data frames, add test

if (!vec_is(x) || is.data.frame(x)) {

abort_enframe_must_be_vector(x)

}

if (is.null(name)) {

df <- list(vectbl_set_names(x))

} else if (is.null(vec_names(x))) {

df <- list(seq_len(vec_size(x)), x)

} else {

df <- list(vec_names2(x), vectbl_set_names(x))

}

names(df) <- c(name, value)

new_tibble(df, nrow = vec_size(x))

}

#' @rdname enframe

#' @description

#' `deframe()` converts two-column data frames to a named vector or list,

#' using the first column as name and the second column as value.

#' If the input has only one column, an unnamed vector is returned.

#' @return For `deframe()`, a vector (named or unnamed).

#' @export

#' @examples

#' deframe(enframe(3:1))

#' deframe(tibble(a = 1:3))

#' deframe(tibble(a = as.list(1:3)))

deframe <- function(x) {

if (length(x) == 1) {

return(x[[1]])

} else if (length(x) != 2) {

warn("`x` must be a one- or two-column data frame in `deframe()`.")

}

value <- x[[2L]]

name <- x[[1L]]

vectbl_set_names(value, as.character(name))

}

abort_enframe_value_null <- function(call = caller_env()) {

tibble_abort(call = call, "`value` can't be NULL.")

}

abort_enframe_must_be_vector <- function(x, call = caller_env()) {

tibble_abort(

call = call,

paste0(

"The `x` argument to `enframe()` must be a vector, not ",

class(x)[[1]],

"."

)

)

}