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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/arrow/r/R/field.R | |
parent | Initial commit. (diff) | |
download | ceph-upstream/18.2.2.tar.xz ceph-upstream/18.2.2.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/arrow/r/R/field.R')
-rw-r--r-- | src/arrow/r/R/field.R | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/src/arrow/r/R/field.R b/src/arrow/r/R/field.R new file mode 100644 index 000000000..d10ee7818 --- /dev/null +++ b/src/arrow/r/R/field.R @@ -0,0 +1,84 @@ +# 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. + +#' @include arrow-package.R +#' @title Field class +#' @usage NULL +#' @format NULL +#' @docType class +#' @description `field()` lets you create an `arrow::Field` that maps a +#' [DataType][data-type] to a column name. Fields are contained in +#' [Schemas][Schema]. +#' @section Methods: +#' +#' - `f$ToString()`: convert to a string +#' - `f$Equals(other)`: test for equality. More naturally called as `f == other` +#' +#' @rdname Field +#' @name Field +#' @export +Field <- R6Class("Field", + inherit = ArrowObject, + public = list( + ToString = function() { + prettier_dictionary_type(Field__ToString(self)) + }, + Equals = function(other, ...) { + inherits(other, "Field") && Field__Equals(self, other) + }, + export_to_c = function(ptr) ExportField(self, ptr) + ), + active = list( + name = function() { + Field__name(self) + }, + nullable = function() { + Field__nullable(self) + }, + type = function() { + Field__type(self) + } + ) +) +Field$create <- function(name, type, metadata, nullable = TRUE) { + assert_that(inherits(name, "character"), length(name) == 1L) + type <- as_type(type, name) + assert_that(missing(metadata), msg = "metadata= is currently ignored") + Field__initialize(enc2utf8(name), type, nullable) +} +#' @include arrowExports.R +Field$import_from_c <- ImportField + +#' @param name field name +#' @param type logical type, instance of [DataType] +#' @param metadata currently ignored +#' @param nullable TRUE if field is nullable +#' +#' @examplesIf arrow_available() +#' field("x", int32()) +#' @rdname Field +#' @export +field <- Field$create + +.fields <- function(.list, nullable = TRUE) { + if (length(.list)) { + assert_that(!is.null(nms <- names(.list))) + map2(nms, .list, field) + } else { + list() + } +} |