mbrobbel commented on code in PR #5822: URL: https://github.com/apache/arrow-rs/pull/5822#discussion_r1928558746
########## arrow-schema/src/extension/canonical/json.rs: ########## @@ -0,0 +1,189 @@ +// 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. + +//! JSON +//! +//! <https://arrow.apache.org/docs/format/CanonicalExtensions.html#json> + +use serde_json::Value; + +use crate::{extension::ExtensionType, ArrowError, DataType}; + +/// The extension type for `JSON`. +/// +/// Extension name: `arrow.json`. +/// +/// The storage type of this extension is `String` or `LargeString` or +/// `StringView`. Only UTF-8 encoded JSON as specified in [rfc8259](https://datatracker.ietf.org/doc/html/rfc8259) +/// is supported. +/// +/// This type does not have any parameters. +/// +/// Metadata is either an empty string or a JSON string with an empty Review Comment: I did consider doing this. The spec states (https://arrow.apache.org/docs/format/CanonicalExtensions.html#json): > Description of the serialization: > Metadata is either an empty string or a JSON string with an empty object. **In the future, additional fields may be added**, but they are not required to interpret the array. So I figured, I'll support the future use-case, however, if/when in the future fields are added here it would actually be better to use a strongly typed definition. I like your suggestion of using `Empty` here and since the metadata content currently is not `pub`, if fields are added in the future, we can just rename and modify the definition of the inner metadata type without introducing a breaking change. [c6f0443](https://github.com/apache/arrow-rs/pull/5822/commits/c6f0443c7cc6eff4d0765366166545d34ef91d69) -- 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]
