The Chez port had landed transients as copy-on-write — each conj!/assoc!/etc.
rebuilt the whole persistent collection. Semantics were right but a transient
vector was O(n^2) to build (the persistent vector is a flat array, so every
conj! copied it); maps/sets were ~O(n log n) since the HAMT only path-copies.
This restores the Janet host's approach: true mutable backing, snapshot once on
persistent!.
vec : a growable Scheme vector (capacity + fill count); conj!/pop! amortized
O(1), persistent! hands off the buffer (exact fit) or trims once.
map : a Chez hashtable keyed by key-hash/jolt= (value equality, nil-safe);
persistent! folds it into a pmap.
set : a Chez hashtable; persistent! folds into a pset.
cow : fallback for anything else (e.g. a sorted coll) keeps the old
copy-on-write path, preserving jolt's superset.
get/count/contains?/nth see through each representation. Building a 400k vector
went from minutes (quadratic) to ~50ms (linear). assoc! keeps the variadic
dangling-key nil-pad on both vectors and maps. test/chez/transient-test.ss pins
the invariants and the linear-time property; wired in as `make transient`.
Allowlist review found three addressable divergences:
- unchecked-char returned a number; the JVM returns a char.
- the readable printer (pr-str, coll elements, the -e/REPL printer) rendered
infinities as Infinity/inf; Clojure's readable form is ##Inf/##-Inf/##NaN
(str/print still gives Infinity). So (pr-str ##Inf) => ##Inf, (str [##Inf]) =>
[##Inf], (str ##Inf) => Infinity.
Corpus 2695->2698; allowlist 43->40 (drop the 3 now-passing entries). Re-minted.
Rephrase comments that pointed at deleted Janet files (emit.janet, the seed
sources, 'the Janet back end punts ...') to present-tense descriptions of the
Chez behavior. Comment/docstring-only; the self-host fixpoint is unchanged
(comments don't affect the compiled seed).
Delete five files that were Janet-host shims with no Chez path: clojure.java.io
(provided natively by host/chez/io.ss), and jolt.{nrepl,png,interop,shell}
(the janet.* bridge, os/shell, janet.net — none exist on Chez).
jolt-cf1q.6
__pr-str1/__write/__with-out-str/__eprint/__eprintf resolved to jolt-nil, so the
whole overlay print family (pr-str/pr/prn/print/println/print-str/prn-str/
println-str) hit the apply-jolt-nil crash bucket. jolt-pr-str is str-style
(strings raw); pr-str needs readable (pr) style — strings quoted+escaped at every
level. printing.ss adds the readable renderer (mirrors jolt-pr-str, recurses,
delegates scalars), plus the infinities long-form and a transient arm (those
were crash->divergence reveals once pr-str ran).
jolt-9zhh.
