Function gdn_flush 

pub fn gdn_flush(
    fp: FpUnit,
    row: &mut [f32],
    log: &[Logged<'_>],
    r: usize,
    store: impl Fn(f32) -> f32,
)

A lazily flushed state row’s flush: every logged update replayed over the row in order (gdn_update with value r of each token), exactly as the token-by-token memory makes them, and the row stored once through store.