host/chez/multimethods.ss implements the multimethod runtime: defmulti/defmethod
expand to defmulti-setup/defmethod-setup calls (+ get-method/methods/
remove-method/prefer-method/prefers). A jolt-multifn record carries its dispatch
fn and a jolt=-keyed method table; jolt-invoke dispatches it (exact match, then
isa?/hierarchy with prefer-method, then :default), reusing the overlay's
isa?/derive/make-hierarchy. The multifn's ns comes from a runtime chez-current-ns
(default user; the prelude load sets clojure.core for print-method/print-dup).
Two emit-side changes were needed:
- late-bind (:late-bind-unresolved? ctx flag, default OFF): defmulti expands to a
bare-symbol setup call, so the analyzer doesn't intern the name and a forward
reference '(area ...)' after '(defmulti area ...)' in one form was 'Unable to
resolve symbol'. The strict compiler punts these to the interpreter; the Chez
back end has none, so the flag lowers an unresolved symbol to a var-ref against
the compile ns (open-world -e semantics). Set only by the Chez make-ctx /
jolt-chez; the main compiler keeps strict resolution (host_iface late-bind?
defaults nil).
- a :var call head now routes through jolt-invoke, since a late-bound var can hold
a multifn (or keyword/coll IFn), not just a procedure. Transparent for
procedures; the hot self-recursive call is a :local known-proc, stays direct.
Class-based dispatch ((class x)/String) deferred (needs deftype/class subsystem).
Parity 1506 -> 1530/2497, 0 new divergences. emit-test 302/302. Full janet gate
green (the analyzer flag is off there; suite flakiness under parallel load only).
Emit every non-macro clojure.core form through the live analyzer -> Chez emit
pipeline as a def-var! prelude (prelude mode, tier dependency order), load it
before a user expression, and you get an -e-capable jolt-chez: analysis on Janet,
execution on Chez. driver/emit-core-prelude assembles it (each form behind a
silent load guard so the Phase-2 multimethod forms don't break the rest);
bin/jolt-chez is the -e CLI, caching the prelude on disk keyed by source hash.
run-corpus-prelude.janet is the full parity gate this opens, the prelude-backed
sibling of run-corpus-chez. First baseline: 1220/2497 evaluated cases pass, 0 new
divergences (10 allowlisted: dynamic vars, class names, eval-order — deferred
Phase 2). The rest is the punch-list: ~360 emit-fail (real host interop, out of
the analyzer subset) and ~900 runtime crashes, mostly core fns calling
host-coupled seed natives with no Chez shim yet (str/format/vec, transients).
Follow-ups jolt-t6cr/kl2l/q3w8/9ls5.
Two shims landed to get the prelude to load and run. atoms.ss: atom/deref/swap!/
reset! (+ the compare/vals kernel) — needed at load time for
global-hierarchy = (atom (make-hierarchy)). predicates.ss: the type predicates +
name/namespace/boolean the overlay assumes are seed natives, matching the seed's
strict semantics. post-prelude.ss re-asserts char?/atom? after the prelude: the
overlay implements those by reading :jolt/type, which is false for Chez-native
chars/atoms, so its def-var! would clobber the correct native versions.
Per-case Scheme files are PID-unique so a foreground -e never reads a half-written
file while the gate runs.
