gty404 commented on code in PR #61: URL: https://github.com/apache/iceberg-cpp/pull/61#discussion_r2033070013
########## src/iceberg/transform/transform_spec.h: ########## @@ -0,0 +1,117 @@ +/* + * 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. + */ + +#pragma once + +/// \file iceberg/transform/transform_spec.h + +#include <memory> +#include <optional> + +#include "iceberg/arrow_c_data.h" +#include "iceberg/type_fwd.h" + +namespace iceberg { +/// \brief A specification for creating a TransformFunction instance. +/// +/// This struct encapsulates all necessary information to describe a transform, +/// including the type of the transform and any optional parameters it may require. +/// It is used by the TransformFactory to instantiate the corresponding transform +/// implementation. +/// +/// For example: +/// - A Bucket transform with 10 buckets: TransformType::kBucket, params = [10] +/// - An Identity transform: TransformType::kIdentity, no parameters +struct TransformSpec { + /// \brief The type of the transform (e.g., kBucket, kTruncate, kIdentity, etc.) + TransformType transform_type; + + /// \brief Optional parameter values passed to the transform, represented as an + /// ArrowArray. + /// + /// For transforms that require parameters (e.g., Bucket(N)), this holds the arguments + /// as a primitive ArrowArray (e.g., INT32 for num_buckets or width). + /// If the transform does not require parameters, this will be std::nullopt. + std::optional<ArrowArray> params_opt; Review Comment: > > 1. Using ArrowArray is necessary, as different Transforms may use different types and numbers of parameters, which should be needed within the Transform or when creating an instance of the Transform. > > Yes, but why not (say) `vector<variant<...>>`? The parameter list for this variant might be quite long. Additionally, I understand that there is also logic to convert from JSON to ArrowArray in other places, and using ArrowArray would be more natural. However, this is just my personal opinion. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
