[ARROW-11773] [Rust] Allow json writer to write out JSON arrays as well as newline formatted objects

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0
• Component/s: Rust
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/27625
• Assignee: Andrew Lamb
• Reporter: Andrew Lamb
• Created: 24/Feb/21 22:30
• Updated: 11/Jan/23 08:22
• Resolved: 26/Feb/21 22:12

Description

Currently the arrow json writer makes JSON that looks like this (one record per line):
```

{"foo":1} {"bar":1}

```

Whereas a JSON array looks like this
```
[

{"foo":1}

,

{"bar":1}

]
```
It would be nice to write out json in a streaming fashion (we added such a feature in IOx via https://github.com/influxdata/influxdb_iox/pull/870/files)

/// Writes out well formed JSON arays in a streaming fashion
///
/// [

{"foo": "bar"}

,

{"foo": "baz"}

]
///
/// This is based on the arrow JSON writer (json::writer::Writer)

Issue Links

• links to: GitHub Pull Request #9575