jolt/jolt-core/clojure/core/40-lazy.clj
Yogthos 780b6474ff core: Stage 3 — leaf batch 3: empty/assoc-in/update-in + interpose/take-nth to the overlay
empty, assoc-in, and update-in move to 20-coll.clj as the canonical recursive
ports; interpose and take-nth move to the lazy tier WITH their canonical
transducer arities (volatile-based), so the seed's td-interpose/td-take-nth
helpers go too. (empty lazy-seq) is () now — the kernel fn returned a bare
host table for it.

keys/vals/empty? stay put for now: they're expander-coupled — 00-syntax's
when/and/or/cond/destructure expanders call them at expansion time, which
happens during the kernel-tier compile, before any later tier exists. They
move when early defns get the staged-recompile treatment macros already have.

26 new spec rows (incl. transducer arities through sequence/into and laziness
checks against (range)). Gate green: conformance 326x3, suite >= baseline,
full jpm test.
2026-06-10 15:26:41 -04:00

177 lines
5.1 KiB
Clojure

;; clojure.core — lazy tier. Canonical CLJS-based lazy seq fns.
;; Loaded after 30-macros.clj, so lazy-seq macro is available.
;;
;; Each fn ported from CLJS core.cljs, stripped of chunked-seq branches.
;; --- distinct --- (transducer + lazy collection arity; value-based dedup)
(defn distinct
([]
(fn [rf]
(let [seen (volatile! #{})]
(fn ([] (rf)) ([result] (rf result))
([result input]
(if (contains? @seen input)
result
(do (vswap! seen conj input) (rf result input))))))))
([coll]
(let [step (fn step [xs seen]
(lazy-seq
((fn [[f :as xs] seen]
(when-let [s (seq xs)]
(if (contains? seen f)
(recur (rest s) seen)
(cons f (step (rest s) (conj seen f))))))
xs seen)))]
(step coll #{}))))
;; --- keep ---
(defn keep
([f]
(fn [rf]
(fn ([] (rf)) ([result] (rf result))
([result input]
(let [v (f input)]
(if (nil? v) result (rf result v)))))))
([f coll]
(lazy-seq
(when-let [s (seq coll)]
(let [x (f (first s))]
(if (nil? x)
(keep f (rest s))
(cons x (keep f (rest s)))))))))
;; --- keep-indexed ---
(defn keep-indexed
([f]
(fn [rf]
(let [ia (volatile! -1)]
(fn ([] (rf)) ([result] (rf result))
([result input]
(let [i (vswap! ia inc)
v (f i input)]
(if (nil? v) result (rf result v))))))))
([f coll]
(letfn [(keepi [idx coll]
(lazy-seq
(when-let [s (seq coll)]
(let [x (f idx (first s))]
(if (nil? x)
(keepi (inc idx) (rest s))
(cons x (keepi (inc idx) (rest s))))))))]
(keepi 0 coll))))
;; --- map-indexed ---
(defn map-indexed
([f]
(fn [rf]
(let [i (volatile! -1)]
(fn ([] (rf)) ([result] (rf result))
([result input] (rf result (f (vswap! i inc) input)))))))
([f coll]
(letfn [(mapi [idx coll]
(lazy-seq
(when-let [s (seq coll)]
(cons (f idx (first s)) (mapi (inc idx) (rest s))))))]
(mapi 0 coll))))
;; --- cycle ---
(defn cycle [coll]
(if-let [vals (seq coll)]
(let [n (count vals)]
(letfn [(cstep [i]
(lazy-seq
(cons (nth vals (mod i n)) (cstep (inc i)))))]
(cstep 0)))
()))
;; --- repeatedly --- ((f) throws on a non-fn; (take n …) throws on a non-number
;; count — both now enforced in the seed (jolt-call / core-take), so the canonical
;; CLJ form matches the repeatedly.cljc exception cases.)
(defn repeatedly
([f] (lazy-seq (cons (f) (repeatedly f))))
([n f] (take n (repeatedly f))))
;; --- repeat ---
(defn repeat
([x] (lazy-seq (cons x (repeat x))))
([n x] (take n (repeat x))))
;; --- iterate ---
(defn iterate [f x]
(lazy-seq (cons x (iterate f (f x)))))
;; --- partition-all --- (transducer + [n coll] + [n step coll])
;; The collection arities realize EXACTLY n per chunk via a first/rest loop and
;; continue from the advanced cursor (not a re-drop / nthrest), so they realize
;; minimally — matching the Janet pstep the §6.3 laziness counters were written
;; against. (A take/nthrest form is correct but over-realizes.)
(defn partition-all
([n]
(fn [rf]
(let [a (volatile! [])]
(fn
([] (rf))
([result]
(let [result (if (zero? (count @a))
result
(let [v @a] (vreset! a []) (unreduced (rf result v))))]
(rf result)))
([result input]
(vswap! a conj input)
(if (= n (count @a))
(let [v @a] (vreset! a []) (rf result v))
result))))))
([n coll]
(letfn [(go [s]
(lazy-seq
(when (seq s)
(loop [i 0 chunk [] cur s]
(if (and (< i n) (seq cur))
(recur (inc i) (conj chunk (first cur)) (rest cur))
(cons chunk (go cur)))))))]
(go coll)))
([n step coll]
(letfn [(go [s]
(lazy-seq
(when (seq s)
(cons (take n s) (go (nthrest s step))))))]
(go coll))))
;; --- Phase 2 leaf batch 3 (jolt-ded): canonical lazy + transducer arities ----
(defn interpose
([sep]
(fn [rf]
(let [started (volatile! false)]
(fn
([] (rf))
([result] (rf result))
([result input]
(if (deref started)
(let [sepr (rf result sep)]
(if (reduced? sepr)
sepr
(rf sepr input)))
(do (vreset! started true)
(rf result input))))))))
([sep coll]
(drop 1 (interleave (repeat sep) coll))))
(defn take-nth
([n]
(fn [rf]
(let [iv (volatile! -1)]
(fn
([] (rf))
([result] (rf result))
([result input]
(let [i (vswap! iv inc)]
(if (zero? (rem i n))
(rf result input)
result)))))))
([n coll]
(lazy-seq
(when-let [s (seq coll)]
(cons (first s) (take-nth n (drop n s)))))))