simon/jolt

History

Yogthos b879430618 seq fns are lazy by default, like Clojure (LazySeq, not eager-headed) map/filter/remove/take/drop/concat/take-while/drop-while/mapcat/partition built an eager-headed cseq: the first element (and the fn application) ran at construction, so a side-effecting (map f coll) fired f immediately and (class (map …)) was PersistentList instead of LazySeq. This diverged from Clojure, which wraps the whole body in lazy-seq. It went unnoticed because the conformance gate certifies values, not realization — eager and lazy heads produce identical values — and unit.edn even baked PersistentList in as expected. test.check's for-all-takes-multiple-expressions (which counts side effects in a for-all body) exposed it. Wrap each native producer's result in a lazy-seq node so the body, incl. the first element, defers until forced — the forced cseq still has eager heads, so reduce/count/dorun/etc. force on walk and there's no per-element cost. dedupe's (seq coll) is moved inside its lazy-seq. A jolt LazySeq is now recognized by coll?/empty, the analyzer's form predicates (a macro can build its expansion with map), value-host-tags + instance? (LazySeq/ISeq/ Sequential), and reports clojure.lang.LazySeq. Kept the native Scheme implementations rather than porting Clojure's: a straight lazy-seq+cons port is 3x slower and Clojure's chunked fast path is 288x slower because jolt's chunk machinery is unoptimized (filed jolt-j9dz); the wrapped natives are Clojure-lazy at native speed. +12 corpus rows (laziness at construction, LazySeq type, both JVM-certified). make test + shakesmoke green, selfhost holds, 0 new divergences.		2026-06-28 00:16:47 -04:00
..
image.ss	spec.alpha: reify ILookup get, NPE/CCE, quoted #inst/#uuid, anon-fn class, kwargs map	2026-06-27 21:56:04 -04:00
prelude.ss	seq fns are lazy by default, like Clojure (LazySeq, not eager-headed)	2026-06-28 00:16:47 -04:00
README.md	Docs: Chez-only, drop the Janet-era references and obsolete migration notes	2026-06-22 09:05:35 -04:00

README.md

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.