[ARROW-1674] [C++] Add ExtensionType implementation for 8-bit boolean values

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• Labels: good-second-issue pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/17682
• Assignee: Unassigned
• Reporter: Wes McKinney
• Created: 14/Oct/17 15:55
• Updated: 11/Jan/23 07:16

Description

Some libraries (e.g. NumPy) represent boolean values using an array of int8 or uint8 values of 1's and 0's. This can present a challenge at times to receive such memory without copying.

Now that we have ExtensionType capabilities, we could define an extension type distinguish UInt8/Int8-annotated-as-boolean to be able to flow through such data in applications.

A discussion about introducing a new logical type didn't go anywhere, so having a custom container that can be used for these specialized applications is one way to unblock the use case. If we develop some endogenous use of such data in C++, we would need to be mindful to sanitize it to bitpacked boolean before sending to another Arrow application

Issue Links

• links to: GitHub Pull Request #1201
• links to: GitHub Pull Request #1201