jolt/jolt-core/clojure/core/00-kernel.clj
Yogthos d77b4e6420 Migrate clojure.core/set from a native shim to the kernel overlay tier
set was a native shim (apply jolt-hash-set (seq->list coll)). It is a
pure composition, so the Clojure version (apply hash-set (seq coll))
lowers to the same code. The compiler uses set, but only off the emit
path (the backend's bare-native-names def and type inference), so it can
live in the kernel tier: compiling that tier never calls set, and by the
time those callers run the tier is already bound.

This is distinct from boolean, which the backend calls for every :if
node on the emit path. Moving boolean even to the kernel tier deadlocks
(compiling the tier that defines boolean needs boolean), so boolean stays
native. Added a comment in predicates.ss recording that.

Re-mint converges in 3 passes and the benchmark suite is unchanged
within noise (collections 43.3 vs 43.1, binary-trees 367 vs 367, the
rest flat).
2026-06-30 10:35:57 -04:00

52 lines
2.4 KiB
Clojure

;; clojure.core — kernel tier (stage just above the host primitives).
;;
;; These are the structural fns the self-hosted compiler itself uses
;; (jolt.analyzer): second/peek/subvec/mapv/update. Because the compiler must be
;; able to compile the *rest* of clojure.core, anything it calls has to exist
;; before it is built. So this tier is loaded FIRST and, in compile mode, is
;; bootstrap-compiled directly into clojure.core (not routed through the
;; self-hosted pipeline, which would need these to already exist — the
;; circularity that previously forced `second` to stay a host primitive). With this tier
;; in place the analyzer is built against the Clojure definitions.
;;
;; Constraint: depend only on core-renames primitives (first/next/nth/count/conj/
;; vec/map/apply/assoc/get/…, all hardwired to host primitives) and on each other.
(defn second [coll] (first (next coll)))
(defn peek [coll]
(cond
(nil? coll) nil
;; vectors (incl. jolt's eager seq results): last element; lists/seqs: first.
(vector? coll) (if (zero? (count coll)) nil (nth coll (dec (count coll))))
(seq? coll) (first coll)
:else (throw (str "peek not supported on: " coll))))
(defn subvec
([v start] (subvec v start (count v)))
([v start end]
(when (not (vector? v)) (throw (str "subvec requires a vector")))
;; Clojure coerces indices with (int ...): NaN -> 0, floats/ratios truncate
;; toward zero; non-numbers throw. Only then range-check.
(let [coerce (fn [x]
(cond
(not (number? x)) (throw (str "subvec index must be a number"))
(not= x x) 0
:else (long x)))
s (coerce start)
e (coerce end)]
(when (or (< s 0) (< e s) (< (count v) e))
(throw (str "subvec index out of range: " s " " e)))
(loop [i s acc []]
(if (< i e) (recur (inc i) (conj acc (nth v i))) acc)))))
(defn mapv [f & colls] (vec (apply map f colls)))
(defn update [m k f & args] (assoc m k (apply f (get m k) args)))
;; set: realize a seqable and dedup through the set constructor; nil -> #{}. The
;; compiler uses it off the emit path (backend bare-native-names, type inference),
;; so unlike boolean it can live here — compiling this tier never calls set, and by
;; the time those callers run the tier is bound. Pure composition of hash-set/seq/
;; apply, so it lowers to the same code the native shim did.
(defn set [coll] (if (nil? coll) #{} (apply hash-set (seq coll))))