simon/jolt

Yogthos cb3cfaf0c2 Chez Phase 1 (increment 3b): seq tier + dynamic IFn dispatch on the Chez RT

Brings up the seq layer on the Chez runtime. host/chez/seq.ss adds one
lazy-capable node (cseq) that models Clojure's list, cons, and lazy seq -
all print as (...), all sequential-= to each other and to vectors. seq
coerces any seqable (vector/map/set/string/list/seq/nil) to a cseq or nil;
the empty seq is a distinct value printing () (rest of a 1-elem coll is ()
not nil, seq of empty is nil). Leaf ops: first/rest/next/seq/cons/list,
reverse/last, map/filter/remove/reduce/into, range/take/drop/concat/apply,
keys/vals, plus nth/peek/pop extended over seqs. map/filter/reduce apply
their fn arg through jolt-invoke, so a procedure, keyword, or collection all
work as the fn.

Dynamic IFn dispatch: a keyword/vector/coll held in a local (let binding or
fn param) and called as a fn now routes through the jolt-invoke fallback
(procedure? -> apply; keyword/coll -> lookup). The emitter only routes a
:local callee that isn't a known procedure - a named fn's self-recursion
name stays a direct call, so the fib hot path is untouched. Closes the 3
ex-known IFn divergences.

emit.janet: seq/pred ops added to native-ops with arity gates; value-position
clojure.core refs resolve to the RT procedure (native-ops names one for each),
with +/-/*// routed to flonum-coercing wrappers so higher-order arithmetic
((reduce + [])) keeps the all-double model. values.ss: cross-type sequential
=/hash so a vector and a list of the same elements are jolt= and hash alike.
rt.ss: printer learns seqs; top-level nil prints as the empty string (jolt -e
str-style). Fixed latent bug: (conj nil ...) now builds a list, not a vector.

Gates: emit-test 69/69 (fib/mandelbrot/collections/seq/IFn parity vs the jolt
oracle, fib(30) ~24ms unchanged). Subset probe 433/436 -> 595/595 compiled,
0 divergences (was 3 known), 2060/2655 out of subset. Full run-tests green
(125 files, conformance + suites included).

2026-06-17 15:19:18 -04:00

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Chez port — Phase 0 test contract harness

The host-neutral correctness gate for the Chez re-host (epic jolt-cf1q). The spec corpus is data, so the SAME contract validates every host.

Files

extract-corpus.janet — parses test/spec/*.janet (defspec …) tables as data and writes corpus.edn (2655 [label expected actual] cases). The file is valid as BOTH EDN (a future Chez-jolt runner) and Janet data (the runner below). Regenerate: janet test/chez/extract-corpus.janet.
corpus.edn — the extracted contract (generated; checked in for convenience).
run-corpus.janet — drives a TARGET jolt binary, one fresh subprocess per case (fresh ctx = per-case isolation), checking (= expected actual) prints true at the CLI, or that a :throws case exits non-zero. Pluggable target:
- janet test/chez/run-corpus.janet # default build/jolt
- JOLT_BIN=build/jolt-chez janet test/chez/run-corpus.janet # Phase 1+
- JOLT_CORPUS_LIMIT=400 … # every-Nth stride, fast
known-divergences.edn — allowlist of cases that diverge at the CLI boundary. The gate fails only on a NEW divergence; known ones are reported but tolerated.
values-test.ss / ../../host/chez/values.ss — Phase 0a value model + tests.

The reference baseline (2026-06-17, Janet `build/jolt`, compile mode)

2641/2655 pass; 14 known divergences. They split into:

interpret-vs-compile leniency — :throws cases where interpret mode raises but compile mode returns (< nil, > with nil, neg? keyword, max/min-key on non-numbers). Several are also non-canonical vs JVM Clojure.
invoke-collection-as-fn — the transient / invokable lookup suite invokes transients/collections as fns (((transient {:x 7}) :x)); compile mode (and JVM Clojure) reject it.
xml-seq walks — one structural case.

The compile-only Chez host (JVM-canonical oracle) should MATCH OR FIX these. The gate's job is to catch regressions the port introduces, not to bless these.

Why the CLI boundary

The runner tests through jolt -e, exactly how the Chez host will be exercised — not the in-process eval-string the Janet defspec harness uses. The two differ on a handful of cases (the allowlist), and the CLI boundary is the portable one.

Phase 1 — first parity number (subset probe)

The full run-corpus.janet gate drives an -e-capable jolt binary; the Chez host can't answer arbitrary -e until all of clojure.core is bootstrapped onto Chez (Phase 2). Until then, run-corpus-chez.janet reports parity for the subset the Phase-1 back end (host/chez/emit.janet) can already compile: each case is run through the live analyzer → Scheme emitter → Chez via host/chez/driver. Cases that reference unimplemented stdlib/host fns fail to EMIT (a clean compile-time signal) and are counted "out of subset", not as divergences.

JOLT_CHEZ_CORPUS=1 janet test/chez/run-corpus-chez.janet

Baseline after inc 3b (seq tier + dynamic IFn, jolt-5pso): 595/595 compiled cases pass, 0 divergences; 2060/2655 out of subset (await clojure.core on Chez). The seq tier brought up a list/lazy-seq type with first/rest/next/seq/cons/list, map/filter/reduce/into/remove, range/take/drop/concat/apply, keys/vals, and nth/peek/pop over seqs; dynamic IFn dispatch (a keyword/vector/coll held in a local and called as a fn) now routes through the jolt-invoke fallback, closing the 3 ex-known divergences. The probe exits non-zero on any NEW divergence.

(Prior, inc 3a: 433/436 compiled, 3 known IFn divergences, 2219 out of subset. Inc 2: 182/182 compiled, 0 divergences, 2473 out of subset.)

It's a slow report (a Chez subprocess per case), so it's gated behind JOLT_CHEZ_CORPUS out of the default suite, like the benches. test/chez/emit-test.janet is the fast Phase-1 unit gate (real analyzer → Chez parity for fib/mandelbrot + collections + regressions); both skip cleanly when chez isn't on PATH.

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