jolt/host/chez/printing.ss
Yogthos 473d1002b7 Reader attaches collection metadata to data, not a with-meta form
The reader lowered ^meta on a vector/map/set literal to a runtime
(with-meta form meta) list, so read-string/edn of data with metadata
returned the form and lost the metadata. Attach it to the value instead,
as Clojure does; the analyzer re-emits (with-meta coll meta) for a
meta-carrying collection literal in code, so a literal still carries its
metadata at runtime and ^Type/^long arglist hints (consumed by
analyze-arity directly) are unaffected.

Also: pr honors *print-meta*, and clojure.walk/clojure.edn re-attach
metadata to the collections they rebuild (matches Clojure; a
metadata-driven config lib like aero relies on it).
2026-06-24 12:04:36 -04:00

124 lines
5.7 KiB
Scheme

;; readable printer + output seams — the __pr-str1 / __write / __with-out-str
;; host seams the overlay's pr-str/pr/prn/print/println/*-str family is built on
;; (jolt-core/clojure/core/20-coll.clj).
;;
;; jolt-pr-str (rt.ss) is STR-style: strings render raw. pr-str needs READABLE
;; (pr) style: strings quoted+escaped at every nesting level. This adds the
;; readable renderer; it mirrors jolt-pr-str but quotes strings and recurses into
;; itself, delegating scalars (nil/bool/number/keyword/symbol/char/regex) to
;; jolt-pr-str (already readable for those). The canonical ORDERED printer is
;; still future work — unordered colls render in HAMT order, compared via `=`.
;; inner string escape (no surrounding quotes): " \ newline tab return.
(define (jolt-str-escape s)
(let loop ((cs (string->list s)) (acc '()))
(if (null? cs)
(list->string (reverse acc))
(loop (cdr cs)
(let ((c (car cs)))
(case c
((#\") (cons #\" (cons #\\ acc)))
((#\\) (cons #\\ (cons #\\ acc)))
((#\newline) (cons #\n (cons #\\ acc)))
((#\tab) (cons #\t (cons #\\ acc)))
((#\return) (cons #\r (cons #\\ acc)))
(else (cons c acc))))))))
;; A host shim registers a type's readable rendering via register-pr-readable-arm!,
;; or register-pr-arm! for types whose str and readable forms match (most host types:
;; inst, uuid, record, var, …). Disjoint types, checked before the base cases.
(define jolt-pr-readable-arms '())
(define (register-pr-readable-arm! pred render)
(set! jolt-pr-readable-arms (cons (cons pred render) jolt-pr-readable-arms)))
(define (register-pr-arm! pred render)
(register-pr-str-arm! pred render)
(register-pr-readable-arm! pred render))
(define (jolt-pr-readable-base x)
(cond
((string? x) (string-append "\"" (jolt-str-escape x) "\""))
;; pr renders the infinities / NaN in READABLE form (##Inf reads back), unlike
;; str's "Infinity"/"-Infinity"/"NaN". Applies at every nesting level.
((and (flonum? x) (fl= x +inf.0)) "##Inf")
((and (flonum? x) (fl= x -inf.0)) "##-Inf")
((and (flonum? x) (not (fl= x x))) "##NaN")
;; transients print as a cold tagged type (print-method routes this through a
;; multimethod; the readable fallback renders it directly).
;; forward refs to transients.ss (loaded later) — resolved at call time.
((jolt-transient? x)
(case (jolt-transient-kind x)
((vec) "#<transient vector>") ((set) "#<transient set>") (else "#<transient map>")))
((pvec? x)
(let ((acc '()))
(let loop ((i (fx- (pvec-count x) 1)))
(when (fx>=? i 0)
(set! acc (cons (jolt-pr-readable (pvec-nth-d x i jolt-nil)) acc))
(loop (fx- i 1))))
(string-append "[" (jolt-str-join acc) "]")))
((pset? x)
(string-append "#{" (jolt-str-join (pset-fold x (lambda (e a) (cons (jolt-pr-readable e) a)) '())) "}"))
((pmap? x)
(string-append "{" (jolt-str-join
(pmap-fold x (lambda (k v a)
(cons (string-append (jolt-pr-readable k) " " (jolt-pr-readable v)) a)) '())) "}"))
((empty-list-t? x) "()")
((cseq? x)
(string-append "(" (jolt-str-join
(let loop ((s x) (acc '()))
(if (jolt-nil? s) (reverse acc)
(loop (jolt-seq (seq-more s)) (cons (jolt-pr-readable (seq-first s)) acc))))) ")"))
(else (jolt-pr-str x))))
(define (jolt-pr-readable-dispatch x)
(let loop ((as jolt-pr-readable-arms))
(cond ((null? as) (jolt-pr-readable-base x))
(((caar as) x) ((cdar as) x))
(else (loop (cdr as))))))
;; *print-meta* support. The var is def'd after this file loads, so capture its
;; cell lazily; jolt-var-get (patched by dyn-binding.ss) honors a `binding`.
(define pr-meta-cell #f)
(define (pr-print-meta?)
(unless pr-meta-cell (set! pr-meta-cell (jolt-var "clojure.core" "*print-meta*")))
(jolt-truthy? (jolt-var-get pr-meta-cell)))
;; The metadata to print before x, or jolt-nil. A var prints as #'ns/name (its
;; {:ns :name} is derived, not user metadata) and a procedure is opaque — skip both.
(define (pr-user-meta x)
(if (or (var-cell? x) (procedure? x)) jolt-nil (jolt-meta x)))
(define (jolt-pr-readable x)
(if (pr-print-meta?)
(let ((m (pr-user-meta x)))
(if (jolt-nil? m)
(jolt-pr-readable-dispatch x)
(string-append "^" (jolt-pr-readable-dispatch m) " " (jolt-pr-readable-dispatch x))))
(jolt-pr-readable-dispatch x)))
;; __pr-str1: render ONE value readably (the overlay's pr-str joins these).
(define (jolt-pr-str1 x) (jolt-pr-readable x))
;; __write: push a string to *out* (current-output-port, so __with-out-str's
;; redirect captures it). Returns nil.
(define (jolt-write s) (display s) jolt-nil)
;; __with-out-str: run a jolt thunk with *out* rebound to a string port, return
;; the captured text.
(define (jolt-with-out-str thunk)
(with-output-to-string (lambda () (jolt-invoke thunk))))
;; __eprint / __eprintf: stderr seams. Flush each write — like the JVM's
;; auto-flushing System.err — so a long-running process (a server that never
;; returns from -main) shows its log lines instead of leaving them in a buffer
;; that only drains at exit.
(define (jolt-eprint s)
(display s (current-error-port))
(flush-output-port (current-error-port))
jolt-nil)
(define (jolt-eprintf fmt . args)
(apply fprintf (current-error-port) fmt args)
(flush-output-port (current-error-port))
jolt-nil)
(def-var! "clojure.core" "__pr-str1" jolt-pr-str1)
(def-var! "clojure.core" "__write" jolt-write)
(def-var! "clojure.core" "__with-out-str" jolt-with-out-str)
(def-var! "clojure.core" "__eprint" jolt-eprint)
(def-var! "clojure.core" "__eprintf" jolt-eprintf)