Broaden the Scheme back end past the numeric/functional subset to vectors,
maps, and sets. host/chez/collections.ss adds a copy-on-write persistent
vector and a bitmap HAMT (the structure 0c measured self-hostable) backing
both maps and sets, keyed by jolt-hash and compared by jolt=. emit.janet
emits :vector/:map/:set literals to the rt constructors and lowers the leaf
ops (conj/get/nth/count/assoc/dissoc/contains?/empty?/peek/pop) via the
native-ops path, with a per-op arity gate.
Also: keyword/map literals in fn position lower to jolt-get ((:k m), ({:k v} k));
arity-1 comparisons emit the vacuous jolt truth (Scheme < rejects a non-number
even at arity 1); count returns a flonum and vector indices coerce from flonum,
both consequences of the all-double number model; values.ss = / hash and the
rt printer learn collections (maps/sets render in HAMT order, so the probe
compares unordered values via =, not printed form).
Subset parity 182 -> 433/436 compiled cases (2219/2655 out of subset), 0 new
divergences. The 3 known divergences are dynamic IFn dispatch (a keyword/vector
held in a local, called as a fn) — deferred to the IFn/protocol increment and
allowlisted in the probe. emit-test 31/31, full run-tests green (125 files).
Wire the real pipeline end to end: host/chez/driver.janet boots a compile-mode
jolt ctx, runs the EXISTING Janet-hosted analyzer on actual Clojure source to
real IR, feeds it to the Scheme emitter, and runs the result on Chez. Analysis
stays on Janet (the analyzer ports to Chez in Phase 2); execution is on Chez.
emit.janet now consumes live IR (pv/phm-normalized like the Janet backend) and
covers what the analyzer actually emits, not the hand-built inc-1 shapes:
- core ops arrive as :var clojure.core/+ etc., not :rt — lowered to native
Scheme via a native-ops table (mirrors backend.janet's), `=` to jolt=.
- var cells (host/chez/rt.ss): :def -> def-var!, :var -> var-deref. Late binding
so cross-var calls (run -> count-point) and the entry crossing resolve at use.
- named fns (defn / fn self-name) bind via letrec so self-recursion resolves.
- unsupported stdlib/host refs (no core on Chez yet) are rejected at EMIT time
(clean out-of-subset signal) instead of deref'ing to nil and failing at runtime.
Number model: jolt is all-doubles (no ratios; (/ 1 2) is 0.5), so literals emit
as flonums — matches the Janet host and keeps Chez out of exploding exact
rationals (mandelbrot). jolt-num->string prints integer-valued without ".0".
Two real bugs found via the corpus probe and fixed (regression rows added):
- loop bound in parallel (Scheme named-let) but Clojure loop is sequential — a
later init must see earlier bindings; wrap a let* around the loop.
- #(...) shorthand gensyms params with a trailing `#`, invalid in Scheme — munge
it to `_`.
Gate: test/chez/emit-test.janet runs the real analyzer -> Chez for (+ 1 2),
fib(30)=832040, mandelbrot run(40), and the two regressions, parity-checked
against the Janet oracle (6/6). First parity number via the new subset probe
(test/chez/run-corpus-chez.janet, JOLT_CHEZ_CORPUS=1): 182/182 compiled corpus
cases pass, 0 divergences; 2473/2655 out of subset pending core on Chez. Full
jpm/run-tests gate green (125 files). Chez tests skip cleanly without `chez`.
Perf note (unchanged plan): emitted fib(30) ~23ms vs hand-Scheme ~5ms — the
jolt-truthy? wrapper (~3x) plus flonum (not fixnum) arithmetic, both Phase-4
type-specialization levers.
