a68210e440
(partition-all n) and (partition-by f) now return stateful transducers, so they compose with into/sequence/transduce/comp (previously errored "called with 1 argument, expected 2"). Both buffer a window, emit on boundary, flush a partial trailing window in the completion arity, and honor `reduced` (early stop drops the in-progress window, no extra trailing partition) — matching Clojure. partition-all: td-partition-all in core.janet (Janet, alongside the other td-*), core-partition-all made variadic. partition-by: transducer arity added to the overlay defn in Clojure with volatiles (stays with its lazy collection arity). Gate: conformance 253x3 (+4 transducer cases incl comp + reduced), lazy-infinite 44/44, fixpoint, self-host, specs+unit green. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
61 lines
No EOL
2.4 KiB
Clojure
61 lines
No EOL
2.4 KiB
Clojure
;; clojure.core — seq tier. Pure-Clojure leaf sequence fns on top of the kernel
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;; tier (00-kernel) and the Janet seed. Loaded after the kernel tier; in compile
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;; mode these self-host through the now-built analyzer (interpreted otherwise).
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;;
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;; Migration rule for adding fns here: the fn must (1) NOT be in
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;; compiler/core-renames (that map emits core-X Janet symbols directly), (2) have
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;; no internal Janet callers of its core-X binding, and (3) NOT be used by the
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;; self-hosted compiler (jolt-core/jolt/*.clj). Compiler-facing structural fns go
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;; in the kernel tier (00-kernel) instead — see its header.
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(defn ffirst [coll] (first (first coll)))
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(defn nfirst [coll] (next (first coll)))
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(defn fnext [coll] (first (next coll)))
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(defn nnext [coll] (next (next coll)))
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;; Canonical Clojure defs: pure first/next/loop/recur, no Janet realize-for-iteration.
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(defn last [s]
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(if (next s) (recur (next s)) (first s)))
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(defn butlast [s]
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(loop [ret [] s s]
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(if (next s)
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(recur (conj ret (first s)) (next s))
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(seq ret))))
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;; partition-by: (partition-by f) is a stateful transducer (buffer a run, emit on
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;; key change, flush on completion — via volatiles, matching Clojure); (partition-by
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;; f coll) is the lazy collection arity.
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(defn partition-by
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([f]
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(fn [rf]
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(let [buf (volatile! [])
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pv (volatile! nil)
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started (volatile! false)]
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(fn
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([] (rf))
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([result]
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(let [b @buf
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result (if (zero? (count b))
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result
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(do (vreset! buf []) (unreduced (rf result b))))]
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(rf result)))
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([result input]
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(let [val (f input)]
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(if (or (not @started) (= val @pv))
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(do (vreset! started true) (vreset! pv val) (vswap! buf conj input) result)
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(let [b @buf]
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(vreset! buf []) (vreset! pv val)
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(let [ret (rf result b)]
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(when-not (reduced? ret) (vswap! buf conj input))
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ret)))))))))
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([f coll]
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(let [step (fn step [s]
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(lazy-seq
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(let [s (seq s)]
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(when s
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(let [fst (first s)
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fv (f fst)
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run (cons fst (take-while (fn [x] (= fv (f x))) (rest s)))]
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(cons run (step (lazy-seq (drop (count run) s)))))))))]
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(step coll)))) |