[ARROW-14650] [JS] toArray equivalent to values/values64

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Implemented
• Fix Version/s: 7.0.0
• Component/s: JavaScript
• External issue URL: https://github.com/apache/arrow/issues/30193
• Assignee: Unassigned
• Reporter: Nicholas Roberts
• Created: 10/Nov/21 02:37
• Updated: 11/Jan/23 08:41
• Resolved: 16/Jan/22 17:30

Description

As discussed in ARROW-10901, 64 bit integer vectors have values64 getters available for systems with support for BigInt typed arrays. Column-oriented dataframe libraries (such as UW's arquero) generally use the Chunked::toArray convenience method in favour of directly dealing with chunks or vectors, and therefore always receive the int32/uint32 data.

I think there are a few alternatives for improving high level access to a 64 bit column's values:

• An optional bit width (or is64Bit, like the <T>::from variants) parameter in Chunked::toArray, IntVector::toArray.
• A new Chunked::toArray64 method, and the same on IntVector (or at least, the 64 bit variants).
• Use values64 directly in the consuming library (loop over the chunks, copy into a destination typed array).

The toArray64 option would probably be a bit of a mess (requiring a fallback to toArray on BaseVector), an optional parameter might be the cleanest approach.