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#' Row-wise tibble creation
#'
#' @description
#' Create [tibble]s using an easier to read row-by-row layout.
#' This is useful for small tables of data where readability is
#' important. Please see \link{tibble-package} for a general introduction.
#'
#' @param ... <[`dynamic-dots`][rlang::dyn-dots]>
#' Arguments specifying the structure of a `tibble`.
#' Variable names should be formulas, and may only appear before the data.
#' These arguments are processed with [rlang::list2()]
#' and support unquote via [`!!`] and unquote-splice via [`!!!`].
#' @return A [tibble].
#' @seealso
#' See [quasiquotation] for more details on tidy dots semantics,
#' i.e. exactly how the `...` argument is processed.
#' @export
#' @examples
#' tribble(
#' ~colA, ~colB,
#' "a", 1,
#' "b", 2,
#' "c", 3
#' )
#'
#' # tribble will create a list column if the value in any cell is
#' # not a scalar
#' tribble(
#' ~x, ~y,
#' "a", 1:3,
#' "b", 4:6
#' )
#' @examplesIf rlang::is_installed("dplyr") && packageVersion("dplyr") >= "1.0.5"
#'
#' # Use dplyr::mutate(dplyr::across(...)) to assign an explicit type
#' tribble(
#' ~ a, ~ b, ~ c,
#' 1, "2000-01-01", "1.5"
#' ) %>%
#' dplyr::mutate(
#' dplyr::across(a, as.integer),
#' dplyr::across(b, as.Date)
#' )
tribble <- function(...) {
data <- extract_frame_data_from_dots(...)
turn_frame_data_into_tibble(data$frame_names, data$frame_rest)
}
#' Row-wise matrix creation
#'
#' @description
#' Create matrices laying out the data in rows, similar to
#' `matrix(..., byrow = TRUE)`, with a nicer-to-read syntax.
#' This is useful for small matrices, e.g. covariance matrices, where readability
#' is important. The syntax is inspired by [tribble()].
#'
#' @param ... <[`dynamic-dots`][rlang::dyn-dots]>
#' Arguments specifying the structure of a `frame_matrix`.
#' Column names should be formulas, and may only appear before the data.
#' These arguments are processed with [rlang::list2()]
#' and support unquote via [`!!`] and unquote-splice via [`!!!`].
#' @return A [matrix].
#' @seealso
#' See [quasiquotation] for more details on tidy dots semantics,
#' i.e. exactly how the `...` argument is processed.
#' @export
#' @examples
#' frame_matrix(
#' ~col1, ~col2,
#' 1, 3,
#' 5, 2
#' )
frame_matrix <- function(...) {
data <- extract_frame_data_from_dots(...)
turn_frame_data_into_frame_matrix(data$frame_names, data$frame_rest)
}
extract_frame_data_from_dots <- function(...) {
dots <- list2(...)
# Extract the names.
frame_names <- extract_frame_names_from_dots(dots)
# Extract the data
if (length(frame_names) == 0 && length(dots) != 0) {
cnd_signal(error_tribble_needs_columns())
}
frame_rest <- dots[-seq_along(frame_names)]
if (!is.null(names(frame_rest))) {
cnd_signal(error_tribble_named_after_tilde())
}
if (length(frame_rest) == 0L) {
# Can't decide on type in absence of data -- use logical which is
# coercible to all types
frame_rest <- unspecified()
}
validate_rectangular_shape(frame_names, frame_rest)
list(frame_names = frame_names, frame_rest = frame_rest)
}
extract_frame_names_from_dots <- function(dots) {
frame_names <- character()
for (i in seq_along(dots)) {
el <- dots[[i]]
if (!is.call(el)) {
break
}
if (!identical(el[[1]], as.name("~"))) {
break
}
if (length(el) != 2) {
cnd_signal(error_tribble_lhs_column_syntax(el[[2]]))
}
candidate <- el[[2]]
if (!(is.symbol(candidate) || is.character(candidate))) {
cnd_signal(error_tribble_rhs_column_syntax(candidate))
}
frame_names <- c(frame_names, as.character(candidate))
}
frame_names
}
validate_rectangular_shape <- function(frame_names, frame_rest) {
if (length(frame_names) == 0 && length(frame_rest) == 0) return()
# Figure out the associated number of rows and number of columns,
# and validate that the supplied formula produces a rectangular
# structure.
if (length(frame_rest) %% length(frame_names) != 0) {
cnd_signal(error_tribble_non_rectangular(
length(frame_names),
length(frame_rest)
))
}
}
turn_frame_data_into_tibble <- function(names, rest) {
if (is_empty(names)) return(new_tibble(list(), nrow = 0))
nrow <- length(rest) / length(names)
dim(rest) <- c(length(names), nrow)
dimnames(rest) <- list(names, NULL)
frame_mat <- t(rest)
frame_col <- turn_matrix_into_column_list(frame_mat)
new_tibble(frame_col, nrow = nrow)
}
turn_matrix_into_column_list <- function(frame_mat) {
frame_col <- vector("list", length = ncol(frame_mat))
names(frame_col) <- colnames(frame_mat)
# if a frame_mat's col is a list column, keep it unchanged (does not unlist)
for (i in seq_len(ncol(frame_mat))) {
col <- frame_mat[, i]
if (inherits(col, "list") && !some(col, needs_list_col)) {
subclass_tribble_c_errors(
names(frame_col)[[i]],
col <- vec_c(!!! unname(col))
)
}
frame_col[[i]] <- unname(col)
}
return(frame_col)
}
turn_frame_data_into_frame_matrix <- function(names, rest) {
list_cols <- which(map_lgl(rest, needs_list_col))
if (has_length(list_cols)) {
cnd_signal(error_frame_matrix_list(list_cols))
}
frame_ncol <- length(names)
frame_mat <- matrix(unlist(rest), ncol = frame_ncol, byrow = TRUE)
colnames(frame_mat) <- names
frame_mat
}
subclass_tribble_c_errors <- function(name, code) {
withCallingHandlers(
code,
vctrs_error = function(cnd) {
cnd_signal(error_tribble_c(name, cnd))
}
)
}
# Errors ------------------------------------------------------------------
error_tribble_needs_columns <- function() {
tibble_error("Must specify at least one column using the `~name` syntax.")
}
error_tribble_named_after_tilde <- function() {
tibble_error("When using the `~name` syntax, subsequent values must not have names.")
}
error_tribble_lhs_column_syntax <- function(lhs) {
tibble_error(bullets(
"All column specifications must use the `~name` syntax.",
paste0("Found ", expr_label(lhs), " on the left-hand side of `~`.")
))
}
error_tribble_rhs_column_syntax <- function(rhs) {
tibble_error(bullets(
'All column specifications must use the `~name` or `~"name"` syntax.',
paste0("Found ", expr_label(rhs), " on the right-hand side of `~`.")
))
}
error_tribble_non_rectangular <- function(cols, cells) {
tibble_error(bullets(
"Data must be rectangular:",
paste0("Found ", cols, " columns."),
paste0("Found ", cells, " cells."),
i = paste0(cells, " is not an integer multiple of ", cols, ".")
))
}
error_frame_matrix_list <- function(pos) {
tibble_error(bullets(
"All values must be atomic:",
pluralise_commas("Found list-valued element(s) at position(s) ", pos, ".")
))
}
error_tribble_c <- function(name, cnd) {
cnd$message <- paste0("Can't create column ", tick(name), ": ", cnd_header(cnd))
cnd$class <- c(tibble_error_class("tribble_c"), class(cnd))
cnd
}