3638521e2d
Three pure function combinators into the collection tier, as compositions of mapv/every?/some/apply. Three more core-* primitives + table entries gone. Battery 3916 -> 3920 (the canonical defs are more correct than the prior Janet ones — some-fn returns the matching value, every-pred is properly boolean). Conformance 218/218 all modes.
63 lines
2.4 KiB
Clojure
63 lines
2.4 KiB
Clojure
;; clojure.core — collection tier. Pure, eager fns expressed as compositions of
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;; already-frozen core primitives (reduce/assoc/get/conj/filter/vec/count/>=).
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;; No host internals, no laziness, no macros — so they compile cleanly and stay
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;; redefinable. Loaded after the seq tier; self-hosted in compile mode.
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;;
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;; Same migration rule as the seq tier (see 10-seq.clj): not in core-renames, no
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;; internal Janet callers, not used by the self-hosted compiler.
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;; Base is (hash-map), not the {} literal: a literal map is a struct that doesn't
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;; canonicalize collection keys across representations (a {:a 1} literal vs
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;; (hash-map :a 1) key), whereas a PHM does — so counting/grouping by collection
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;; value needs the PHM base (the prior Janet impl used make-phm for this reason).
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(defn frequencies [coll]
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(reduce (fn [counts x] (assoc counts x (inc (get counts x 0)))) (hash-map) coll))
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(defn group-by [f coll]
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(reduce (fn [ret x] (let [k (f x)] (assoc ret k (conj (get ret k []) x)))) (hash-map) coll))
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(defn not-empty [coll]
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(if (or (nil? coll) (zero? (count coll))) nil coll))
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(defn filterv [pred coll]
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(vec (filter pred coll)))
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;; Greatest/least x by (k x). Canonical Clojure multi-arity: the first pair uses
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;; strict < / > and the fold uses <= / >= — this exact ordering reproduces the
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;; JVM IEEE-754 NaN behavior (e.g. (min-key identity 1 ##NaN) => ##NaN). > / <
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;; throw on non-numbers, as Clojure does.
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(defn max-key
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([k x] x)
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([k x y] (if (> (k x) (k y)) x y))
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([k x y & more]
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(let [kx (k x) ky (k y)
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v (if (> kx ky) x y)
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kv (if (> kx ky) kx ky)]
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(loop [v v kv kv more more]
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(if (seq more)
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(let [w (first more) kw (k w)]
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(if (>= kw kv) (recur w kw (next more)) (recur v kv (next more))))
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v)))))
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(defn min-key
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([k x] x)
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([k x y] (if (< (k x) (k y)) x y))
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([k x y & more]
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(let [kx (k x) ky (k y)
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v (if (< kx ky) x y)
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kv (if (< kx ky) kx ky)]
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(loop [v v kv kv more more]
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(if (seq more)
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(let [w (first more) kw (k w)]
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(if (<= kw kv) (recur w kw (next more)) (recur v kv (next more))))
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v)))))
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;; Function combinators (pure HOFs).
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(defn juxt [& fs]
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(fn [& args] (mapv (fn [f] (apply f args)) fs)))
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(defn every-pred [& preds]
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(fn [& xs] (every? (fn [p] (every? p xs)) preds)))
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(defn some-fn [& preds]
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(fn [& xs] (some (fn [p] (some p xs)) preds)))
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