jolt/host/chez/lazy-bridge.ss
Yogthos e434356590 Replace str-render/instance-check set! chains with registries
jolt-str-render-one and instance-check were each extended by a chain of
set!-wrapping closures spread across ~10 and ~5 host files, so the real
behavior of either was scattered and load-order-dependent. Give each a
registry the base file owns: converters.ss/records-interop.ss define the
registry plus a register-* helper, and each extending file registers one arm
instead of capturing %prev and set!-ing the global.

str-render arms are type-disjoint; instance-check arms run newest-first (the
old outermost-wins order) and may return 'pass to defer. The string-token ->
symbol normalization the natives-array arm did for every inner arm moves to
the dispatcher head; array tokens stay strings for that arm to decide.

jolt-ogib.14. Runtime-only shims, no re-mint.
2026-06-23 09:05:36 -04:00

84 lines
4.4 KiB
Scheme

;; lazy-seq bridge — make-lazy-seq / coll->cells.
;;
;; The `lazy-seq` macro (00-syntax.clj) expands to
;; (make-lazy-seq (fn* [] (coll->cells (do body))))
;; and `lazy-cat` to (concat (lazy-seq c) ...). These back every overlay fn
;; built on lazy-seq — repeat / iterate / cycle / dedupe / take-nth / keep /
;; interpose / reductions / tree-seq (-> flatten) / lazy-cat.
;;
;; Bridge to the cseq model (seq.ss): a `jolt-lazyseq` is a deferred seq — a 0-arg
;; thunk that, when forced once, yields a seq (cseq | nil). coll->cells coerces the
;; body result to a seq (= jolt-seq), so the thunk already returns a seq; jolt-seq
;; is extended to force a lazyseq. The one trap: (cons x (a-lazy-seq)) must NOT
;; force the tail (else (repeat x) = (lazy-seq (cons x (repeat x))) loops forever),
;; so jolt-cons defers a lazyseq tail into a lazy cseq cell.
;;
;; Loaded LAST (after host-table.ss): %ls-seq then captures the fully-extended
;; jolt-seq (sorted-aware), so a lazy body returning a sorted coll still seqs.
(define-record-type jolt-lazyseq
(fields (mutable thunk) (mutable val) (mutable realized?))
(nongenerative jolt-lazyseq-v1))
(define (jolt-make-lazy-seq thunk) (make-jolt-lazyseq thunk jolt-nil #f))
;; force once and memoize. The thunk is (fn [] (coll->cells body)); coll->cells
;; already coerced the body to a seq (cseq | nil) via the live jolt-seq, so the
;; result needs no further coercion (a nested lazyseq was forced by coll->cells).
(define (force-lazyseq x)
(if (jolt-lazyseq-realized? x)
(jolt-lazyseq-val x)
(let ((r (jolt-invoke (jolt-lazyseq-thunk x))))
(jolt-lazyseq-val-set! x r)
(jolt-lazyseq-realized?-set! x #t)
(jolt-lazyseq-thunk-set! x #f)
r)))
;; coll->cells: coerce the body result to the cell representation = a seq | nil.
(define (jolt-coll->cells c) (jolt-seq c))
;; extend jolt-seq to force a lazyseq (a lazyseq is seqable -> its realized seq).
(define %ls-seq jolt-seq)
(set! jolt-seq (lambda (x) (if (jolt-lazyseq? x) (force-lazyseq x) (%ls-seq x))))
;; (cons x lazyseq): keep the tail lazy — force it only when the cseq cell is
;; walked, so an infinite (repeat/iterate/cycle) stays productive.
(define %ls-cons jolt-cons)
(set! jolt-cons (lambda (x coll)
(if (jolt-lazyseq? coll)
(cseq-lazy x (lambda () (force-lazyseq coll)))
(%ls-cons x coll))))
;; A lazyseq is a NEW value type, so the dispatchers that DON'T route through
;; jolt-seq must learn it or a raw (unrealized) lazyseq escapes — e.g. the corpus
;; compares (= [1 3 5] (take-nth 2 …)) against the raw lazyseq, and jolt=2 would
;; see an unknown type and return false. Recognizing it as sequential is enough
;; for equality + hash (seq=? / seq-hash coerce via jolt-seq); count / empty? /
;; nth / the printers don't, so coerce those explicitly.
(define %ls-sequential? jolt-sequential?)
(set! jolt-sequential? (lambda (x) (or (jolt-lazyseq? x) (%ls-sequential? x))))
(define %ls-count jolt-count)
(set! jolt-count (lambda (x) (if (jolt-lazyseq? x) (%ls-count (jolt-seq x)) (%ls-count x))))
(define %ls-empty? jolt-empty?)
(set! jolt-empty? (lambda (x) (if (jolt-lazyseq? x) (%ls-empty? (jolt-seq x)) (%ls-empty? x))))
(define %ls-nth jolt-nth)
(set! jolt-nth (case-lambda
((coll i) (if (jolt-lazyseq? coll) (%ls-nth (jolt-seq coll) i) (%ls-nth coll i)))
((coll i d) (if (jolt-lazyseq? coll) (%ls-nth (jolt-seq coll) i d) (%ls-nth coll i d)))))
(define %ls-pr-str jolt-pr-str)
(set! jolt-pr-str (lambda (x) (if (jolt-lazyseq? x) (%ls-pr-str (jolt-seq x)) (%ls-pr-str x))))
(define %ls-pr-readable jolt-pr-readable)
(set! jolt-pr-readable (lambda (x) (if (jolt-lazyseq? x) (%ls-pr-readable (jolt-seq x)) (%ls-pr-readable x))))
(register-str-render! jolt-lazyseq? (lambda (x) (jolt-str-render-one (jolt-seq x))))
;; seq? — a lazy seq IS a seq (predicates.ss's jolt-seq? predates the lazyseq
;; record). Unlike the native-op dispatchers above (called via a direct top-level
;; reference, so the set! is enough), seq? is reached through var-deref, which
;; reads the var-cell root — so the patched closure must be re-def-var!'d, not just
;; set!. (Exposed once dynamic binding let with-in-str/line-seq reach seq?.)
(define %ls-seq? jolt-seq?)
(set! jolt-seq? (lambda (x) (or (jolt-lazyseq? x) (%ls-seq? x))))
(def-var! "clojure.core" "seq?" jolt-seq?)
(def-var! "clojure.core" "make-lazy-seq" jolt-make-lazy-seq)
(def-var! "clojure.core" "coll->cells" jolt-coll->cells)