Under direct-linking a record is a Janet tuple (its shape-rec), and core-vector?
just delegated to jvec? which is true for any tuple — so (vector? a-record) and
(sequential? a-record) returned true. That broke map-destructuring of a record:
the destructure coerce treats a sequential source as & {:keys} kwargs and does
(apply hash-map x), so destructuring a record fed its entries to make-phm as a
flat kv-list and corrupted. Surfaced as reitit's router crashing on a wildcard
route ('expected integer key for tuple in range [0,5), got 5') whenever the new
direct-link default was on; minimal repro is (let [{:keys [a]} (->R ...)] ...).
Fix: core-vector? excludes shape-recs, matching Clojure (a record is not a
vector or sequential). jvec? is unchanged for internal representation dispatch.
Regression cases added to record-declared-shape-test.
Records (defrecord/deftype) are now shape-recs in a direct-linking unit by
default — no JOLT_SHAPE flag. A record's shape is DECLARED, so the inference
proves field reads by a lookup, not fragile shape inference, and they bare-index.
Result: ~1.4x faster than the :jolt/deftype table form on a record-heavy loop
(3.9s vs 5.5s), driven by cheaper construction + proven bare-index reads.
Two gates now:
- :shapes? — shape-recs active; records use declared-shape layout + bare
index reads. On with direct-linking (where the inference runs).
- :map-shapes? — also shape generic const-key maps. Opt-in (JOLT_SHAPE), because
shaping maps net-loses on unproven reads (measured). Records win.
- call-ret-type types a record ctor (->Name) as a struct of its declared shape,
fed from a ctx-env registry populated at deftype; field reads on the result
bare-index. (set-record-shapes!/set-map-shapes! wired through infer-unit!.)
- sidx reads the field's position from the :shape vector AS-IS (declared order
for records, str-sorted for map literals) — no re-sort — so any field order
bare-indexes correctly. The map :map case only sets :shape under :map-shapes?.
- record-shape-for interns the descriptor per (type, fields), not per type: a
record redefined with different fields now gets a fresh descriptor instead of a
stale one (fixes redef descriptor staleness; old instances stay valid).
Adds record-declared-shape-test (declared-order reads, incl. non-alphabetical
fields, through fn boundaries + protocol method bodies). Known pre-existing edge
case filed as jolt-wf4 (direct (:f (->R …)) read returns nil after a record is
redefined with different fields; let-bound read works; repros without shapes).
