wgtmac commented on code in PR #905: URL: https://github.com/apache/iceberg-cpp/pull/905#discussion_r3926141546
########## src/iceberg/util/iterator.h: ########## @@ -0,0 +1,91 @@ +/* + * 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/util/iterator.h +/// \brief Pull-based iterator interface for fallible, lazily produced values. + +#include <deque> +#include <optional> +#include <type_traits> +#include <utility> +#include <vector> + +#include "iceberg/result.h" + +namespace iceberg { + +/// \brief A pull-based iterator whose reads may fail. +/// +/// Iterator implementations own any resources needed to produce values. Destroying an +/// iterator releases those resources, including when iteration stops before reaching the +/// end. Iterators are not thread-safe unless an implementation explicitly says otherwise. +/// +/// \tparam T Value returned by the iterator. +template <typename T> +class Iterator { + public: + virtual ~Iterator() = default; + + Iterator() = default; + Iterator(const Iterator&) = delete; + Iterator& operator=(const Iterator&) = delete; + + /// \brief Return the next value, or std::nullopt when the iterator is exhausted. + virtual Result<std::optional<T>> Next() = 0; Review Comment: What should happen after `Next()` returns an error or EOF? A caller can call it again today, but the iterator may already be partly advanced. Please make that state terminal (or document that the iterator must not be reused) and add a repeated-call test. ########## src/iceberg/util/iterator.h: ########## @@ -0,0 +1,91 @@ +/* + * 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/util/iterator.h +/// \brief Pull-based iterator interface for fallible, lazily produced values. + +#include <deque> +#include <optional> +#include <type_traits> +#include <utility> +#include <vector> + +#include "iceberg/result.h" + +namespace iceberg { + +/// \brief A pull-based iterator whose reads may fail. +/// +/// Iterator implementations own any resources needed to produce values. Destroying an +/// iterator releases those resources, including when iteration stops before reaching the +/// end. Iterators are not thread-safe unless an implementation explicitly says otherwise. +/// +/// \tparam T Value returned by the iterator. +template <typename T> +class Iterator { + public: + virtual ~Iterator() = default; + + Iterator() = default; + Iterator(const Iterator&) = delete; Review Comment: Because this class deletes copy operations and declares a destructor, it has no implicit move operations. A derived iterator's default move constructor is therefore deleted too. If this is meant to be move-only, please explicitly default move construction/assignment; otherwise document that implementations must be pointer-owned. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
