Function execute_morsels_ordered 

pub fn execute_morsels_ordered<T>(
    admission: &MorselAdmission,
    execute: impl FnMut(Morsel) -> Result<T>,
) -> Result<Vec<T>>

Executes morsels in ordinal order, stopping at the first callback error.

This materializing baseline is consumed by the executor vectorization benchmark and tests/morsel_oracle.rs, which qualifies both materializing shared-pool methods and the production accounted stream against an independent row oracle. Parallel callbacks may already be running when one fails; their side effects need not match the sequential baseline’s fail-fast behavior.