thisisnic commented on code in PR #13786: URL: https://github.com/apache/arrow/pull/13786#discussion_r959320472
########## r/R/dplyr-across.R: ########## @@ -0,0 +1,166 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +expand_across <- function(.data, quos_in) { + quos_out <- list() + # retrieve items using their values to preserve naming of quos other than across + for (quo_i in seq_along(quos_in)) { + quo_in <- quos_in[quo_i] + quo_expr <- quo_get_expr(quo_in[[1]]) + quo_env <- quo_get_env(quo_in[[1]]) + + if (is_call(quo_expr, "across")) { + new_quos <- list() + + across_call <- match.call( + definition = dplyr::across, + call = quo_expr, + expand.dots = FALSE, + envir = quo_env + ) + + if (!all(names(across_call[-1]) %in% c(".cols", ".fns", ".names"))) { + abort("`...` argument to `across()` is deprecated in dplyr and not supported in Arrow") + } + + if (!is.null(across_call[[".cols"]])) { + cols <- across_call[[".cols"]] + } else { + cols <- quote(everything()) + } + + setup <- across_setup( + cols = !!as_quosure(cols, quo_env), + fns = across_call[[".fns"]], + names = across_call[[".names"]], + .caller_env = quo_env, + mask = .data, + inline = TRUE + ) + + # calling across() with .fns = NULL returns all columns unchanged + if (is_empty(setup$fns)) { + # this needs to be updated to match dplyr's version + return() + } + + if (!is_list(setup$fns) && as.character(setup$fns)[[1]] == "~") { + abort( + paste( + "purrr-style lambda functions as `.fns` argument to `across()`", + "not yet supported in Arrow" + ) + ) + } + + new_quos <- quosures_from_func_list(setup, quo_env) + + quos_out <- append(quos_out, new_quos) + } else { + quos_out <- append(quos_out, quo_in) + } + } + + quos_out +} + +# given a named list of functions and column names, create a list of new quosures +quosures_from_func_list <- function(setup, quo_env) { + func_list_full <- rep(setup$fns, length(setup$vars)) + cols_list_full <- rep(setup$vars, each = length(setup$fns)) + + # get new quosures + new_quo_list <- map2( + func_list_full, cols_list_full, + ~ quo(!!call2(.x, sym(.y))) + ) + + quosures <- set_names(new_quo_list, setup$names) + map(quosures, ~ quo_set_env(.x, quo_env)) +} + +across_setup <- function(cols, fns, names, .caller_env, mask, inline = FALSE) { + cols <- enquo(cols) + + vars <- names(dplyr::select(mask, !!cols)) + + if (is.null(fns)) { + if (!is.null(names)) { + glue_mask <- across_glue_mask(.caller_env, .col = vars, .fn = "1") + names <- vctrs::vec_as_names(glue::glue(names, .envir = glue_mask), repair = "check_unique") + } else { + names <- vars + } + value <- list(vars = vars, fns = fns, names = names) + return(value) + } + + # apply `.names` smart default + if (is.function(fns) || is_formula(fns) || is.name(fns)) { + names <- names %||% "{.col}" + fns <- list("1" = fns) + } else { + names <- names %||% "{.col}_{.fn}" + fns <- call_args(fns) + } + + if (any(map_lgl(fns, is_formula))) { + abort( + paste( + "purrr-style lambda functions as `.fns` argument to `across()`", + "not yet supported in Arrow" + ) + ) + } + + if (!is.list(fns)) { + msg <- c("`.fns` must be NULL, a function, a formula, or a list of functions/formulas.") + abort(msg) + } + + # make sure fns has names, use number to replace unnamed + if (is.null(names(fns))) { + names_fns <- seq_along(fns) + } else { + names_fns <- names(fns) + empties <- which(names_fns == "") + if (length(empties)) { + names_fns[empties] <- empties + } + } + + glue_mask <- across_glue_mask(.caller_env, + .col = rep(vars, each = length(fns)), + .fn = rep(names_fns, length(vars)) + ) + names <- vctrs::vec_as_names(glue::glue(names, .envir = glue_mask), repair = "check_unique") + + if (!inline) { + fns <- map(fns, as_function) + } + + list(vars = vars, fns = fns, names = names) +} + +across_glue_mask <- function(.col, .fn, .caller_env) { + glue_mask <- env(.caller_env, .col = .col, .fn = .fn) + env_bind_active( + glue_mask, + col = function() glue_mask$.col, fn = function() glue_mask$.fn + ) + glue_mask Review Comment: Got this from `dplyr::across()` and don't 100% understand it, but changing it to your version doesn't make any tests fails, so have updated it for now. May be due to the way that `dplyr` subsequently executes these functions, which is fundamentally different to how we do it in `arrow`. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
