Clojure `any?`

any.clj

(ns user
  (:require [clojure.test :refer [are deftest]]
            [clojure.test.check.clojure-test :refer [defspec]]
            [clojure.test.check.generators :as gen]
            [clojure.test.check.properties :as prop])
  (:refer-clojure :exclude [any?]))

(comment
  "Clojure's `any? ` function seems to just return `true ` always."
  (defn any?
    "Returns true given any argument."
    {:tag Boolean
     :added "1.9"}
    [x] true)

  "Contrast this with `not-any? `."
  (def
    ^{:tag Boolean
      :doc "Returns false if (pred x) is logical true for any x in coll,
  else true."
      :arglists '([pred coll])
      :added "1.0"}
    not-any? (comp not some))

  "I believe `any? ` should take two arguments and return `true ` if any predicate is `true `."
  (def
    ^{:tag Boolean
      :doc "Returns true if (pred x) is logical true for any x in coll,
  else false."
      :arglists '([pred coll])
      :added "1.9"}
    any? (comp boolean some))

  "Credit to Kofrasa on ClojureDocs."
  "https://clojuredocs.org/clojure.core/any_q"
  "https://clojuredocs.org/u/kofrasa"
  )

;; This demonstrates the mistake in implementation.
(deftest clojure-any
  (are [x y] (= ((comp boolean some) true? x) (clojure.core/any? y))
    [true] true
    [false] false ;; this fails
    [true true] true
    [false true] true
    [false false] false ;; so does this
    ))

(def
  ^{:tag Boolean
    :doc "Returns true if (pred x) is logical true for any x in coll,
  else false."
    :arglists '([pred coll])
    :added "1.9"}
  any? (comp boolean some))

;; Here is the correct implementation.
(defspec correct-any 1000
  (prop/for-all [v (gen/such-that not-empty (gen/vector gen/boolean))]
                (= ((comp boolean some) true? v)
                   (any? true? v)
                   (not (not-any? true? v)))))