jolt/host/chez/values.ss
Yogthos 5c5d2cd1fc Chez Phase 1 (increment 3a): persistent collections on the Chez RT
Broaden the Scheme back end past the numeric/functional subset to vectors,
maps, and sets. host/chez/collections.ss adds a copy-on-write persistent
vector and a bitmap HAMT (the structure 0c measured self-hostable) backing
both maps and sets, keyed by jolt-hash and compared by jolt=. emit.janet
emits :vector/:map/:set literals to the rt constructors and lowers the leaf
ops (conj/get/nth/count/assoc/dissoc/contains?/empty?/peek/pop) via the
native-ops path, with a per-op arity gate.

Also: keyword/map literals in fn position lower to jolt-get ((:k m), ({:k v} k));
arity-1 comparisons emit the vacuous jolt truth (Scheme < rejects a non-number
even at arity 1); count returns a flonum and vector indices coerce from flonum,
both consequences of the all-double number model; values.ss = / hash and the
rt printer learn collections (maps/sets render in HAMT order, so the probe
compares unordered values via =, not printed form).

Subset parity 182 -> 433/436 compiled cases (2219/2655 out of subset), 0 new
divergences. The 3 known divergences are dynamic IFn dispatch (a keyword/vector
held in a local, called as a fn) — deferred to the IFn/protocol increment and
allowlisted in the probe. emit-test 31/31, full run-tests green (125 files).
2026-06-17 14:33:57 -04:00

84 lines
4 KiB
Scheme

;; Jolt value model on Chez Scheme — Phase 0a (jolt-cf1q.1).
;;
;; The irreducible value layer the self-hosted RT rests on. Maps Clojure's value
;; types onto Chez natives where possible, and adds records only where Chez lacks
;; a distinct type (nil sentinel, keywords, ns-bearing symbols). Loaded into an
;; env that has already (import (chezscheme)); becomes a real library in Phase 1.
;;
;; Design notes:
;; - nil is a UNIQUE sentinel, distinct from #f and '() (the classic Lisp-on-Lisp
;; trap). jolt false -> Chez #f, jolt true -> #t.
;; - Chez's numeric tower IS Clojure's: long->exact integer, double->flonum,
;; ratio->exact rational, bigint->bignum. A windfall vs Janet (ratios/bignums
;; for free). Clojure `=` is exactness-aware: (= 1 1.0) is FALSE.
;; --- nil ---------------------------------------------------------------------
(define-record-type jolt-nil-t (fields) (nongenerative jolt-nil-v1))
(define jolt-nil (make-jolt-nil-t))
(define (jolt-nil? x) (jolt-nil-t? x))
;; --- truthiness: only nil and false are falsey -------------------------------
(define (jolt-truthy? x) (not (or (jolt-nil? x) (eq? x #f))))
;; --- keywords: interned so identity works; optional namespace ----------------
(define-record-type keyword-t (fields ns name khash) (nongenerative keyword-v1))
(define keyword-table (make-hashtable string-hash string=?))
;; NUL separator can't occur in a keyword ns/name, so the intern key is
;; unambiguous (a "/" separator would collide ns="a" name="b/c" with ns="a/b").
(define (keyword-intern-key ns name) (string-append (or ns "") "\x0;" name))
(define (keyword ns name)
(let ((k (keyword-intern-key ns name)))
(or (hashtable-ref keyword-table k #f)
(let ((kw (make-keyword-t ns name (equal-hash k))))
(hashtable-set! keyword-table k kw)
kw))))
(define (keyword? x) (keyword-t? x))
;; --- symbols: ns + name + meta; NOT interned (meta varies), = by ns/name ------
(define-record-type symbol-t (fields ns name meta) (nongenerative symbol-v1))
(define (jolt-symbol ns name) (make-symbol-t ns name jolt-nil))
(define (jolt-symbol/meta ns name meta) (make-symbol-t ns name meta))
(define (jolt-symbol? x) (symbol-t? x))
;; chars/strings: Chez natives (strings treated immutable).
;; --- jolt equality (Clojure =) — scalars; collections land in Phase 2 --------
(define (jolt=2 a b)
(cond
((and (jolt-nil? a) (jolt-nil? b)) #t)
((or (jolt-nil? a) (jolt-nil? b)) #f)
((and (number? a) (number? b)) ; exactness-aware
(and (eq? (exact? a) (exact? b)) (= a b)))
((and (keyword-t? a) (keyword-t? b)) (eq? a b)) ; interned
((and (symbol-t? a) (symbol-t? b))
(and (equal? (symbol-t-ns a) (symbol-t-ns b))
(string=? (symbol-t-name a) (symbol-t-name b))))
((and (char? a) (char? b)) (char=? a b))
((and (string? a) (string? b)) (string=? a b))
((and (boolean? a) (boolean? b)) (eq? a b))
;; collections: forward to collections.ss (loaded after this file by rt.ss).
((and (jolt-coll? a) (jolt-coll? b)) (jolt-coll=? a b))
(else (eq? a b))))
(define (jolt= a . rest)
(let loop ((a a) (rest rest))
(cond ((null? rest) #t)
((jolt=2 a (car rest)) (loop (car rest) (cdr rest)))
(else #f))))
;; --- jolt hash — consistent with jolt= (for the HAMT in 0c / Phase 2) ---------
(define (jolt-hash x)
(cond
((jolt-nil? x) 0)
((keyword-t? x) (keyword-t-khash x))
((symbol-t? x) (equal-hash (cons (symbol-t-ns x) (symbol-t-name x))))
;; distinguish inexact from exact (1 and 1.0 are not jolt=); guard non-finite
;; (inexact->exact would error on NaN/inf)
((number? x) (if (exact? x) (equal-hash x)
(if (and (flonum? x) (or (nan? x) (infinite? x)))
(equal-hash (cons 'inexact (number->string x)))
(equal-hash (cons 'inexact (inexact->exact x))))))
((string? x) (string-hash x))
((char? x) (char->integer x))
((boolean? x) (if x 1 2))
((jolt-coll? x) (jolt-coll-hash x)) ; forward to collections.ss
(else (equal-hash x))))