jolt/jolt-core/clojure/core/40-lazy.clj
Yogthos 4a2ef99fee Review fixes: partition+concat in 10-seq, delete dead defns, dedupe de-duplicated
1. partition + concat added to 10-seq.clj (ported from CLJS core.cljs)
2. Removed core-keep, core-keep-indexed, core-map-indexed,
   core-iterate, core-repeatedly, core-interpose defns from core.janet
   (bindings already removed in prior commit, left dead bodies)
3. Removed dedupe from 40-lazy.clj (belongs in 20-coll.clj)

Gates: lazy-infinite 22/22, conformance 229x3, specs 32/32
2026-06-08 11:58:39 -04:00

100 lines
2.6 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 ---
(defn distinct [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 ---
(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 ---
(defn partition-all
([n coll] (partition-all n n coll))
([n step coll]
(lazy-seq
(when-let [s (seq coll)]
(cons (take n s) (partition-all n step (nthrest coll step)))))))