GH-48505: [GLib][Ruby] Add SkewOptions (#48526)

### Rationale for this change

The `SkewOptions` class is not available in GLib/Ruby, and it is used together with the `skew` compute function.

### What changes are included in this PR?

This adds the `SkewOptions` class to GLib.

### Are these changes tested?

Yes, with Ruby unit tests.

### Are there any user-facing changes?

Yes, a new class.

* GitHub Issue: #48505

Authored-by: Sten Larsson <[email protected]>
Signed-off-by: Sutou Kouhei <[email protected]>

Author: stenlarsson

c_glib/arrow-glib/compute.cpp

@@ -321,6 +321,9 @@ G_BEGIN_DECLS
  * #GArrowSelectKOptions is a class to customize the
  * `select_k_unstable` function.
  *
+ * #GArrowSkewOptions is a class to customize the `skew` and
+ * `kurtosis` functions.
+ *
  * There are many functions to compute data on an array.
  */
 
@@ -9501,6 +9504,143 @@ garrow_select_k_options_add_sort_key(GArrowSelectKOptions *options,
   garrow_raw_sort_keys_add(arrow_options->sort_keys, sort_key);
 }
 
+enum {
+  PROP_SKEW_OPTIONS_SKIP_NULLS = 1,
+  PROP_SKEW_OPTIONS_BIASED,
+  PROP_SKEW_OPTIONS_MIN_COUNT,
+};
+
+G_DEFINE_TYPE(GArrowSkewOptions, garrow_skew_options, GARROW_TYPE_FUNCTION_OPTIONS)
+
+static void
+garrow_skew_options_set_property(GObject *object,
+                                 guint prop_id,
+                                 const GValue *value,
+                                 GParamSpec *pspec)
+{
+  auto options = garrow_skew_options_get_raw(GARROW_SKEW_OPTIONS(object));
+
+  switch (prop_id) {
+  case PROP_SKEW_OPTIONS_SKIP_NULLS:
+    options->skip_nulls = g_value_get_boolean(value);
+    break;
+  case PROP_SKEW_OPTIONS_BIASED:
+    options->biased = g_value_get_boolean(value);
+    break;
+  case PROP_SKEW_OPTIONS_MIN_COUNT:
+    options->min_count = g_value_get_uint(value);
+    break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+    break;
+  }
+}
+
+static void
+garrow_skew_options_get_property(GObject *object,
+                                 guint prop_id,
+                                 GValue *value,
+                                 GParamSpec *pspec)
+{
+  auto options = garrow_skew_options_get_raw(GARROW_SKEW_OPTIONS(object));
+
+  switch (prop_id) {
+  case PROP_SKEW_OPTIONS_SKIP_NULLS:
+    g_value_set_boolean(value, options->skip_nulls);
+    break;
+  case PROP_SKEW_OPTIONS_BIASED:
+    g_value_set_boolean(value, options->biased);
+    break;
+  case PROP_SKEW_OPTIONS_MIN_COUNT:
+    g_value_set_uint(value, options->min_count);
+    break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
+    break;
+  }
+}
+
+static void
+garrow_skew_options_init(GArrowSkewOptions *object)
+{
+  auto priv = GARROW_FUNCTION_OPTIONS_GET_PRIVATE(object);
+  priv->options =
+    static_cast<arrow::compute::FunctionOptions *>(new arrow::compute::SkewOptions());
+}
+
+static void
+garrow_skew_options_class_init(GArrowSkewOptionsClass *klass)
+{
+  auto gobject_class = G_OBJECT_CLASS(klass);
+
+  gobject_class->set_property = garrow_skew_options_set_property;
+  gobject_class->get_property = garrow_skew_options_get_property;
+
+  arrow::compute::SkewOptions options;
+
+  GParamSpec *spec;
+  /**
+   * GArrowSkewOptions:skip-nulls:
+   *
+   * Whether NULLs are skipped or not.
+   *
+   * Since: 23.0.0
+   */
+  spec = g_param_spec_boolean("skip-nulls",
+                              "Skip NULLs",
+                              "Whether NULLs are skipped or not",
+                              options.skip_nulls,
+                              static_cast<GParamFlags>(G_PARAM_READWRITE));
+  g_object_class_install_property(gobject_class, PROP_SKEW_OPTIONS_SKIP_NULLS, spec);
+
+  /**
+   * GArrowSkewOptions:biased:
+   *
+   * Whether the calculated value is biased.
+   * If false, the value computed includes a correction factor to reduce bias.
+   *
+   * Since: 23.0.0
+   */
+  spec =
+    g_param_spec_boolean("biased",
+                         "Biased",
+                         "Whether the calculated value is biased. If false, the value "
+                         "computed includes a correction factor to reduce bias",
+                         options.biased,
+                         static_cast<GParamFlags>(G_PARAM_READWRITE));
+  g_object_class_install_property(gobject_class, PROP_SKEW_OPTIONS_BIASED, spec);
+
+  /**
+   * GArrowSkewOptions:min-count:
+   *
+   * If less than this many non-null values are observed, emit null.
+   *
+   * Since: 23.0.0
+   */
+  spec =
+    g_param_spec_uint("min-count",
+                      "Min count",
+                      "If less than this many non-null values are observed, emit null",
+                      0,
+                      G_MAXUINT,
+                      options.min_count,
+                      static_cast<GParamFlags>(G_PARAM_READWRITE));
+  g_object_class_install_property(gobject_class, PROP_SKEW_OPTIONS_MIN_COUNT, spec);
+}
+
+/**
+ * garrow_skew_options_new:
+ *
+ * Returns: A newly created #GArrowSkewOptions.
+ *
+ * Since: 23.0.0
+ */
+GArrowSkewOptions *
+garrow_skew_options_new(void)
+{
+  return GARROW_SKEW_OPTIONS(g_object_new(GARROW_TYPE_SKEW_OPTIONS, nullptr));
+}
+
 G_END_DECLS
 
 arrow::Result<arrow::FieldRef>
@@ -9746,6 +9886,11 @@ garrow_function_options_new_raw(const arrow::compute::FunctionOptions *arrow_opt
       static_cast<const arrow::compute::SelectKOptions *>(arrow_options);
     auto options = garrow_select_k_options_new_raw(arrow_select_k_options);
     return GARROW_FUNCTION_OPTIONS(options);
+  } else if (arrow_type_name == "SkewOptions") {
+    const auto arrow_skew_options =
+      static_cast<const arrow::compute::SkewOptions *>(arrow_options);
+    auto options = garrow_skew_options_new_raw(arrow_skew_options);
+    return GARROW_FUNCTION_OPTIONS(options);
   } else {
     auto options = g_object_new(GARROW_TYPE_FUNCTION_OPTIONS, NULL);
     return GARROW_FUNCTION_OPTIONS(options);
@@ -10739,3 +10884,24 @@ garrow_select_k_options_get_raw(GArrowSelectKOptions *options)
   return static_cast<arrow::compute::SelectKOptions *>(
     garrow_function_options_get_raw(GARROW_FUNCTION_OPTIONS(options)));
 }
+
+GArrowSkewOptions *
+garrow_skew_options_new_raw(const arrow::compute::SkewOptions *arrow_options)
+{
+  auto options = g_object_new(GARROW_TYPE_SKEW_OPTIONS,
+                              "skip-nulls",
+                              arrow_options->skip_nulls,
+                              "biased",
+                              arrow_options->biased,
+                              "min-count",
+                              arrow_options->min_count,
+                              nullptr);
+  return GARROW_SKEW_OPTIONS(options);
+}
+
+arrow::compute::SkewOptions *
+garrow_skew_options_get_raw(GArrowSkewOptions *options)
+{
+  return static_cast<arrow::compute::SkewOptions *>(
+    garrow_function_options_get_raw(GARROW_FUNCTION_OPTIONS(options)));
+}

c_glib/arrow-glib/compute.h

@@ -1678,4 +1678,17 @@ void
 garrow_select_k_options_add_sort_key(GArrowSelectKOptions *options,
                                      GArrowSortKey *sort_key);
 
+#define GARROW_TYPE_SKEW_OPTIONS (garrow_skew_options_get_type())
+GARROW_AVAILABLE_IN_23_0
+G_DECLARE_DERIVABLE_TYPE(
+  GArrowSkewOptions, garrow_skew_options, GARROW, SKEW_OPTIONS, GArrowFunctionOptions)
+struct _GArrowSkewOptionsClass
+{
+  GArrowFunctionOptionsClass parent_class;
+};
+
+GARROW_AVAILABLE_IN_23_0
+GArrowSkewOptions *
+garrow_skew_options_new(void);
+
 G_END_DECLS

c_glib/arrow-glib/compute.hpp

@@ -303,3 +303,8 @@ GArrowSelectKOptions *
 garrow_select_k_options_new_raw(const arrow::compute::SelectKOptions *arrow_options);
 arrow::compute::SelectKOptions *
 garrow_select_k_options_get_raw(GArrowSelectKOptions *options);
+
+GArrowSkewOptions *
+garrow_skew_options_new_raw(const arrow::compute::SkewOptions *arrow_options);
+arrow::compute::SkewOptions *
+garrow_skew_options_get_raw(GArrowSkewOptions *options);

c_glib/test/test-skew-options.rb

@@ -0,0 +1,60 @@
+# 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.
+
+class TestSkewOptions < Test::Unit::TestCase
+  include Helper::Buildable
+
+  def setup
+    @options = Arrow::SkewOptions.new
+  end
+
+  def test_skip_nulls
+    assert do
+      @options.skip_nulls?
+    end
+    @options.skip_nulls = false
+    assert do
+      not @options.skip_nulls?
+    end
+  end
+
+  def test_biased
+    assert do
+      @options.biased?
+    end
+    @options.biased = false
+    assert do
+      not @options.biased?
+    end
+  end
+
+  def test_min_count
+    assert_equal(0, @options.min_count)
+    @options.min_count = 1
+    assert_equal(1, @options.min_count)
+  end
+
+  def test_skew_function
+    args = [
+      Arrow::ArrayDatum.new(build_double_array([1.0, 1.0, 2.0])),
+    ]
+    @options.min_count = 4
+    skew_function = Arrow::Function.find("skew")
+    result = skew_function.execute(args, @options).value
+    assert_equal(0.0, result.value)
+  end
+end