Brummel
a665a966a7
Turn one value-empty blueprint into a family of disjoint instances over a
declared grid, run them in parallel, and collect per-point metrics. This is
C12.1's grid axis — the first "N instead of 1": #30/#31 made a blueprint
param-generic and bindable; this reaps it.
New module crates/aura-engine/src/sweep.rs, three parts:
- GridSpace: a validated cartesian grid over a blueprint's param_space() —
one discrete value-list per slot, kind/arity/non-empty checked at
construction (SweepError::{Arity, KindMismatch, EmptyAxis}, the typed gate
before any run). points() enumerates in odometer order (last axis fastest),
deterministic.
- sweep(): closure-driven. The engine owns enumeration + disjoint execution
+ collection; the author owns run_one: Fn(&[Scalar]) -> RunMetrics (build
fresh -> bootstrap_with_params -> run -> drain -> summarize). Metrics
reduction is harness-specific sink glue the engine cannot generically own
(C8/C18), and a fresh per-point build resolves #31's two structural facts:
bootstrap_with_params consumes the blueprint, and a Recorder bakes its
channel in — so each point gets its own drainable instance.
- SweepFamily / SweepPoint: ordered, self-describing (params carry the point
coordinate), in enumeration order independent of thread completion.
Execution is std::thread::scope over available_parallelism() workers pulling
point indices from a shared atomic cursor (work-stealing balances uneven
per-point cost); results are tagged by index and sorted after join, so the
family is bit-identical across thread counts and repeated runs (C1: disjoint,
lock-free; order = enumeration, not completion). No external dependency —
std only, never rayon (C16: the engine workspace stays zero-dep for deploy
purity). A private sweep_with_threads(nthreads) lets the tests pin
determinism at 1 vs N workers while the public sweep() derives the count.
Out of scope this iteration: the `aura sweep` CLI demonstrator (cycle 0028
iter 2); random enumeration, per-point manifest assembly (#33), value-domain
validation (C20) are deferred per the spec.
One deviation from the plan's verbatim code: GridSpace derives Debug
(load-bearing — the three .unwrap_err() fault tests need the Ok type to be
Debug to compile).
Verified: 8 new sweep:: tests green (enumeration/odometer order, the three
typed faults, sweep == N independent runs, determinism across thread counts,
distinct-points-distinct-metrics); cargo test --workspace green (92 engine
lib tests, no regression); cargo clippy --workspace --all-targets
-- -D warnings clean.
refs #32