[ARROW-1952] [JS] 32b dense vector coercion

• Type: New Feature
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: JS-0.3.0
• Component/s: JavaScript
• External issue URL: https://github.com/apache/arrow/issues/15640
• Assignee: Paul Taylor
• Reporter: Leo Meyerovich
• Created: 28/Dec/17 03:33
• Updated: 11/Jan/23 07:18
• Resolved: 02/Feb/18 02:01

Description

JS APIs, for better or worse, is quite 32b centric. Currently, JS Arrow does a good job of information-preserving flattening, e.g., 64i vector into an array of [hi, lo] int32s. Something similar for timestamps. ... However .... in getting some Arrow code to load into a legacy system, I'm finding myself to be writing a lot of lossy flatteners in userland. Doing it there seems brittle, error-prone, incurs friction for adoption, and if put in the core lib, enable reuse across libs.

I can imagine at least 2 reasonable interfaces for this:
(1) 64b Vector -> 32b flat array (typed or otherwise). This is the naive, simple thing.
(2) 64b Vector -> 32b Vector , and reuse whatever 32b vector -> flat array logic will available anyways. This helps stay in the symbolic abstraction longer, so may be smarter.

Thoughts?