paleolimbot commented on code in PR #365: URL: https://github.com/apache/arrow-adbc/pull/365#discussion_r1087377117
########## r/adbcdrivermanager/R/driver_void.R: ########## @@ -0,0 +1,89 @@ +# 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. + +#' Create ADBC drivers +#' +#' Creates the R object representation of an ADBC driver, which consists of a +#' name and an initializer function with an optional subclass to control +#' finer-grained behaviour at the R level. +#' +#' @param x,entrypoint An ADBC driver may be defined either as an init function +#' or as an identifier with an entrypoint name. A driver init func +#' must be an external pointer to a DL_FUNC with the type +#' `AdbcDriverInitFunc` specified in the adbc.h header. +#' @param ... Further key/value parameters to store with the (R-level) driver +#' object. +#' @param subclass An optional subclass for finer-grained control of +#' behaviour at the R level. +#' +#' @return An object of class 'adbc_driver' +#' @export +#' +#' @examples +#' adbc_driver_void() +#' +adbc_driver_void <- function() { + if (is.null(internal_driver_env$void)) { + internal_driver_env$void <- adbc_driver( + .Call(RAdbcVoidDriverInitFunc), + subclass = "adbc_driver_void" + ) + } + + internal_driver_env$void +} + +#' @rdname adbc_driver_void +#' @export +adbc_driver <- function(x, entrypoint = NULL, ..., subclass = character()) { + if (inherits(x, "adbc_driver_init_func")) { + driver <- .Call(RAdbcLoadDriverFromInitFunc, x) + driver$driver_init_func <- x + } else { + driver <- .Call(RAdbcLoadDriver, x, entrypoint) + driver$name <- x + driver$entrypoint <- entrypoint + } + + args <- list(...) + for (i in seq_along(args)) { + driver[[names(args)[i]]] <- args[[i]] + } + + class(driver) <- c(subclass, class(driver)) + driver +} + +internal_driver_env <- new.env(parent = emptyenv()) + +#' @export +print.adbc_driver <- function(x, ...) { + str(x, ...) +} + +#' @importFrom utils str +#' @export +str.adbc_driver <- function(object, ...) { Review Comment: Maybe...beyond answering the question "what even is this thing" when debugging R code or writing driver tests, I'm not sure the output of this is all that important. Some user-facing package can call `adbc_connection_get_info()` and make prettier output (and it's a lot easier to do that in R than C). -- 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: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
