jolt/host/chez/seed
Dmitri Sotnikov 0a7e818700
Fixed-arity protocol dispatch shims (#223)
defprotocol emitted one variadic (fn [this & rest] (protocol-dispatch P m this
(list->cseq rest))) per method, so every protocol call — even a no-extra-arg one
like (area s) — consed a rest list, wrapped it in a cseq, var-deref'd
protocol-dispatch, and jolt-invoke'd it (consing again). On mono-dispatch that was
2.07GB of allocation, ~65% of the benchmark.

Emit one fixed-arity clause per declared arglist instead. The 1/2/3-param arities
call positional protocol-dispatch{1,2,3}, which resolve the impl (by record tag,
reify method, or host-tag extension — factored into protocol-resolve) and apply it
directly; no rest-list, no seq round-trip. The dispatchN entry points are in the
native-op table so the shim calls bind straight to the records.ss procedures
rather than var-deref. 4+ params fall back to the variadic protocol-dispatch.

mono-dispatch 1.5s/2.07GB -> 0.69s/280MB; dispatch 26x -> 12.2x, mono-dispatch
111x -> 51x vs JVM. 5 new corpus rows pin multi-arity methods, host-type args,
and protocol-method-as-value against JVM Clojure.

Co-authored-by: Yogthos <yogthos@gmail.com>
2026-06-26 05:57:42 +00:00
..
image.ss Fixed-arity protocol dispatch shims (#223) 2026-06-26 05:57:42 +00:00
prelude.ss Fixed-arity protocol dispatch shims (#223) 2026-06-26 05:57:42 +00:00
README.md Docs: Chez-only, drop the Janet-era references and obsolete migration notes 2026-06-22 09:05:35 -04:00

Chez bootstrap seed

These two files are the bootstrap compiler for jolt — the seed that makes the build self-hosting:

  • prelude.ss — the clojure.core prelude (all tiers + clojure.string/walk/ template/edn/set/pprint) as Scheme def-var! forms.
  • image.ss — the compiler image (jolt.ir + jolt.analyzer + jolt.backend-scheme) as Scheme def-var! forms.

Both are generated, not hand-written. They are checked in because a fresh checkout must be able to build jolt-on-Chez using only Chez: host/chez/bootstrap.ss loads this seed, then rebuilds the prelude + image from the .clj/.ss sources via the on-Chez compiler (read → analyze → emit, all on Chez). The seed is a joint byte-fixpoint: rebuilding from an up-to-date seed reproduces it exactly. make selfhost (host/chez/selfcheck.sh) runs host/chez/bootstrap.ss and diffs the rebuilt artifacts against the checked-in seed.

Re-minting

When the seed sources change (the core tiers, the compiler namespaces, the host contract, the reader, emit-image.ss), the seed drifts and make selfhost fails. Re-mint it by running host/chez/bootstrap.ss and writing the freshly rebuilt prelude/image back to host/chez/seed/prelude.ss / host/chez/seed/image.ss, then commit the refreshed files.