jolt/host/chez/vars.ss
Yogthos 960d8b6e24 refactor: consolidate transducers, dissolve natives-parity.ss (jolt-jcs7)
natives-parity.ss was a grab-bag (its own header called it 'parity'). Dissolve it
into homes that say what they hold:
  - cat            -> natives-transduce.ss (was natives-xform.ss, renamed for the
                      whole transducer surface: volatiles + cat + transduce/sequence)
  - transient?     -> transients.ss
  - rseq           -> natives-seq.ss
  - hash family    -> natives-misc.ss (the public hash API over jolt-hash)
The remainder — the #?() feature set, the reader-conditional + re-matcher tagged-map
ctors, and macroexpand — is a coherent reader/macro runtime-support unit, kept as
natives-reader.ss (np- prefix -> nr-). rt.ss loads + two comment refs updated.

Runtime .ss, no re-mint. make test green; hash/transient?/rseq/cat/macroexpand and
#?() reader features all verified.
2026-06-23 23:50:42 -04:00

50 lines
2.3 KiB
Scheme

;; vars as first-class objects — (var x) / #'x.
;;
;; The emitter lowers :the-var to (jolt-var ns name) — the rt.ss var-cell, which
;; is now also a Clojure VAR value. var? / var-get / deref-of-var / var-as-IFn /
;; var equality / pr-str(#'ns/name) operate on it. bound? is overridden natively
;; in post-prelude.ss (the overlay reads (get v :root), nil on a record).
;;
;; Dynamic binding (binding / with-bindings* / var-set / thread-bound? /
;; with-redefs) lives in dyn-binding.ss, which chains the var-read paths set up
;; here.
;;
;; Loaded LAST (after natives-transduce.ss): chains jolt-deref (atom/volatile arms)
;; and the printers.
(define (jolt-var-pred? x) (var-cell? x))
;; the var's current root; unbound is an error (Clojure throws on an unbound var).
(define (jolt-var-get v)
(if (var-cell? v)
(let ((r (var-cell-root v)))
(if (eq? r jolt-unbound) (error #f "Unbound var" v) r))
(error #f "var-get: not a var" v)))
;; deref of a var -> its root.
(define %v-deref jolt-deref)
(set! jolt-deref (lambda (x) (if (var-cell? x) (jolt-var-get x) (%v-deref x))))
;; a var is an IFn — invoking it invokes its root value ((var f) args -> (f args)).
(define %v-invoke jolt-invoke)
(set! jolt-invoke (lambda (f . args)
(if (var-cell? f) (apply jolt-invoke (var-cell-root f) args) (apply %v-invoke f args))))
;; two var cells are = iff same ns/name (Clojure var identity).
(register-eq-arm! (lambda (a b) (or (var-cell? a) (var-cell? b)))
(lambda (a b) (and (var-cell? a) (var-cell? b)
(string=? (var-cell-ns a) (var-cell-ns b))
(string=? (var-cell-name a) (var-cell-name b)))))
;; pr-str / str of a var -> #'ns/name.
(define (var->str v) (string-append "#'" (var-cell-ns v) "/" (var-cell-name v)))
(register-pr-arm! var-cell? var->str)
(register-str-render! var-cell? var->str)
;; bound? — native (the overlay's (get v :root) is nil on a var-cell record).
(define (jolt-var-bound-one? v) (and (var-cell? v) (not (eq? (var-cell-root v) jolt-unbound))))
(define (jolt-bound? . vars) (if (for-all jolt-var-bound-one? vars) #t #f))
(def-var! "clojure.core" "var?" jolt-var-pred?)
(def-var! "clojure.core" "var-get" jolt-var-get)
(def-var! "clojure.core" "deref" jolt-deref)