should be it

external/duckdb/extension/parquet/reader/variant/variant_value.cpp

@@ -0,0 +1,85 @@
+#include "reader/variant/variant_value.hpp"
+
+namespace duckdb {
+
+void VariantValue::AddChild(const string &key, VariantValue &&val) {
+	D_ASSERT(value_type == VariantValueType::OBJECT);
+	object_children.emplace(key, std::move(val));
+}
+
+void VariantValue::AddItem(VariantValue &&val) {
+	D_ASSERT(value_type == VariantValueType::ARRAY);
+	array_items.push_back(std::move(val));
+}
+
+yyjson_mut_val *VariantValue::ToJSON(ClientContext &context, yyjson_mut_doc *doc) const {
+	switch (value_type) {
+	case VariantValueType::PRIMITIVE: {
+		if (primitive_value.IsNull()) {
+			return yyjson_mut_null(doc);
+		}
+		switch (primitive_value.type().id()) {
+		case LogicalTypeId::BOOLEAN: {
+			if (primitive_value.GetValue<bool>()) {
+				return yyjson_mut_true(doc);
+			} else {
+				return yyjson_mut_false(doc);
+			}
+		}
+		case LogicalTypeId::TINYINT:
+			return yyjson_mut_int(doc, primitive_value.GetValue<int8_t>());
+		case LogicalTypeId::SMALLINT:
+			return yyjson_mut_int(doc, primitive_value.GetValue<int16_t>());
+		case LogicalTypeId::INTEGER:
+			return yyjson_mut_int(doc, primitive_value.GetValue<int32_t>());
+		case LogicalTypeId::BIGINT:
+			return yyjson_mut_int(doc, primitive_value.GetValue<int64_t>());
+		case LogicalTypeId::FLOAT:
+			return yyjson_mut_real(doc, primitive_value.GetValue<float>());
+		case LogicalTypeId::DOUBLE:
+			return yyjson_mut_real(doc, primitive_value.GetValue<double>());
+		case LogicalTypeId::DATE:
+		case LogicalTypeId::TIME:
+		case LogicalTypeId::VARCHAR: {
+			auto value_str = primitive_value.ToString();
+			return yyjson_mut_strncpy(doc, value_str.c_str(), value_str.size());
+		}
+		case LogicalTypeId::TIMESTAMP: {
+			auto value_str = primitive_value.ToString();
+			return yyjson_mut_strncpy(doc, value_str.c_str(), value_str.size());
+		}
+		case LogicalTypeId::TIMESTAMP_TZ: {
+			auto value_str = primitive_value.CastAs(context, LogicalType::VARCHAR).GetValue<string>();
+			return yyjson_mut_strncpy(doc, value_str.c_str(), value_str.size());
+		}
+		case LogicalTypeId::TIMESTAMP_NS: {
+			auto value_str = primitive_value.CastAs(context, LogicalType::VARCHAR).GetValue<string>();
+			return yyjson_mut_strncpy(doc, value_str.c_str(), value_str.size());
+		}
+		default:
+			throw InternalException("Unexpected primitive type: %s", primitive_value.type().ToString());
+		}
+	}
+	case VariantValueType::OBJECT: {
+		auto obj = yyjson_mut_obj(doc);
+		for (const auto &it : object_children) {
+			auto &key = it.first;
+			auto value = it.second.ToJSON(context, doc);
+			yyjson_mut_obj_add_val(doc, obj, key.c_str(), value);
+		}
+		return obj;
+	}
+	case VariantValueType::ARRAY: {
+		auto arr = yyjson_mut_arr(doc);
+		for (auto &item : array_items) {
+			auto value = item.ToJSON(context, doc);
+			yyjson_mut_arr_add_val(arr, value);
+		}
+		return arr;
+	}
+	default:
+		throw InternalException("Can't serialize this VariantValue type to JSON");
+	}
+}
+
+} // namespace duckdb