FA-44482 / Data systems / Member archive

A projected struct field broadcasts its first lane · case 02

A projected struct field broadcasts its first lane.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Project requested fields from a struct array. Parent validity dominates field validity, absent schema fields materialize None, selection retains row order, and projection retains requested field order.

Why this case matters

A bounded deterministic data engine model makes representation and changelog faults reproducible.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
gather with field order	`[[4, 2], [4, 2]]`	`[[5, 3], [4, 2]]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.