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Java example source code file (vectors.clj)

This example Java source code file (vectors.clj) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

classcastexception, copyright, counted, halloway, indexoutofboundsexception, lazyseq, license, nullpointerexception, public, rseq, stuart, the, vecs, you

The vectors.clj Java example source code

;   Copyright (c) Rich Hickey. All rights reserved.
;   The use and distribution terms for this software are covered by the
;   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
;   which can be found in the file epl-v10.html at the root of this distribution.
;   By using this software in any fashion, you are agreeing to be bound by
;   the terms of this license.
;   You must not remove this notice, or any other, from this software.

; Author: Stuart Halloway, Daniel Solano Gómez

(ns clojure.test-clojure.vectors
  (:use clojure.test))

(deftest test-reversed-vec
  (let [r (range 6)
        v (into (vector-of :int) r)
        reversed (.rseq v)]
    (testing "returns the right impl"
      (is (= clojure.lang.APersistentVector$RSeq (class reversed))))
    (testing "RSeq methods"
      (is (= [5 4 3 2 1 0] reversed))
      (is (= 5 (.index reversed)))
      (is (= 5 (.first reversed)))
      (is (= [4 3 2 1 0] (.next reversed)))
      (is (= [3 2 1 0] (.. reversed next next)))
      (is (= 6 (.count reversed))))
    (testing "clojure calling through"
      (is (= 5 (first reversed)))
      (is (= 5 (nth reversed 0))))
    (testing "empty reverses to nil"
      (is (nil? (.. v empty rseq))))))

(deftest test-vecseq
  (let [r (range 100)
        vs (into (vector-of :int) r)
        vs-1 (next vs)
        vs-32 (.chunkedNext (seq vs))]
    (testing "="
      (are [a b] (= a b)
           vs vs
           vs-1 vs-1
           vs-32 vs-32)
      (are [a b] (not= a b)
           vs vs-1
           vs-1 vs
           vs vs-32
           vs-32 vs))
    (testing "IPersistentCollection.empty"
      (are [a] (identical? clojure.lang.PersistentList/EMPTY (.empty (seq a)))
           vs vs-1 vs-32))
    (testing "IPersistentCollection.cons"
      (are [result input] (= result (.cons input :foo))
           [:foo 1] (seq (into (vector-of :int) [1]))))
    (testing "IPersistentCollection.count"
      (are [ct s] (= ct (.count (seq s)))
           100 vs
           99 vs-1
           68 vs-32)
      ;; can't manufacture this scenario: ASeq defers to Counted, but
      ;; LazySeq doesn't, so Counted never gets checked on reified seq below
      #_(testing "hops to counted when available"
        (is (= 200
               (.count (concat
                        (seq vs)
                        (reify clojure.lang.ISeq
                               (seq [this] this)
                               clojure.lang.Counted
                               (count [_] 100))))))))
    (testing "IPersistentCollection.equiv"
      (are [a b] (true? (.equiv a b))
           vs vs
           vs-1 vs-1
           vs-32 vs-32
           vs r)
      (are [a b] (false? (.equiv a b))
           vs vs-1
           vs-1 vs
           vs vs-32
           vs-32 vs
           vs nil))
    (testing "internal-reduce"
      (is (= [99] (into [] (drop 99 vs)))))))

(deftest test-primitive-subvector-reduce
  ;; regression test for CLJ-1082
  (is (== 60 (let [prim-vec (into (vector-of :long) (range 1000))]
               (reduce + (subvec prim-vec 10 15))))))

(deftest test-vec-compare
  (let [nums      (range 1 100)
        ; randomly replaces a single item with the given value
        rand-replace  (fn[val]
                        (let [r (rand-int 99)]
                          (concat (take r nums) [val] (drop (inc r) nums))))
        ; all num sequences in map
        num-seqs      {:standard       nums
                       :empty          '()
                       ; different lengths
                       :longer         (concat nums [100])
                       :shorter        (drop-last nums)
                       ; greater by value
                       :first-greater  (concat [100] (next nums))
                       :last-greater   (concat (drop-last nums) [100])
                       :rand-greater-1 (rand-replace 100)
                       :rand-greater-2 (rand-replace 100)
                       :rand-greater-3 (rand-replace 100)
                       ; lesser by value
                       :first-lesser   (concat [0] (next nums))
                       :last-lesser    (concat (drop-last nums) [0])
                       :rand-lesser-1  (rand-replace 0)
                       :rand-lesser-2  (rand-replace 0)
                       :rand-lesser-3  (rand-replace 0)}
        ; a way to create compare values based on num-seqs
        create-vals   (fn[base-val]
                        (zipmap (keys num-seqs)
                                (map #(into base-val %1) (vals num-seqs))))
        ; Vecs made of int primitives
        int-vecs      (create-vals (vector-of :int))
        ; Vecs made of long primitives
        long-vecs     (create-vals (vector-of :long))
        ; standard boxing vectors
        regular-vecs  (create-vals [])
        ; the standard int Vec for comparisons
        int-vec       (:standard int-vecs)]
    (testing "compare"
      (testing "identical"
        (is (= 0 (compare int-vec int-vec))))
      (testing "equivalent"
        (are [x y] (= 0 (compare x y))
             ; standard
             int-vec (:standard long-vecs)
             (:standard long-vecs) int-vec
             int-vec (:standard regular-vecs)
             (:standard regular-vecs) int-vec
             ; empty
             (:empty int-vecs) (:empty long-vecs)
             (:empty long-vecs) (:empty int-vecs)))
      (testing "lesser"
        (are [x] (= -1 (compare int-vec x))
             (:longer int-vecs)
             (:longer long-vecs)
             (:longer regular-vecs)
             (:first-greater int-vecs)
             (:first-greater long-vecs)
             (:first-greater regular-vecs)
             (:last-greater int-vecs)
             (:last-greater long-vecs)
             (:last-greater regular-vecs)
             (:rand-greater-1 int-vecs)
             (:rand-greater-1 long-vecs)
             (:rand-greater-1 regular-vecs)
             (:rand-greater-2 int-vecs)
             (:rand-greater-2 long-vecs)
             (:rand-greater-2 regular-vecs)
             (:rand-greater-3 int-vecs)
             (:rand-greater-3 long-vecs)
             (:rand-greater-3 regular-vecs))
        (are [x] (= -1 (compare x int-vec))
             nil
             (:empty int-vecs)
             (:empty long-vecs)
             (:empty regular-vecs)
             (:shorter int-vecs)
             (:shorter long-vecs)
             (:shorter regular-vecs)
             (:first-lesser int-vecs)
             (:first-lesser long-vecs)
             (:first-lesser regular-vecs)
             (:last-lesser int-vecs)
             (:last-lesser long-vecs)
             (:last-lesser regular-vecs)
             (:rand-lesser-1 int-vecs)
             (:rand-lesser-1 long-vecs)
             (:rand-lesser-1 regular-vecs)
             (:rand-lesser-2 int-vecs)
             (:rand-lesser-2 long-vecs)
             (:rand-lesser-2 regular-vecs)
             (:rand-lesser-3 int-vecs)
             (:rand-lesser-3 long-vecs)
             (:rand-lesser-3 regular-vecs)))
      (testing "greater"
        (are [x] (= 1 (compare int-vec x))
             nil
             (:empty int-vecs)
             (:empty long-vecs)
             (:empty regular-vecs)
             (:shorter int-vecs)
             (:shorter long-vecs)
             (:shorter regular-vecs)
             (:first-lesser int-vecs)
             (:first-lesser long-vecs)
             (:first-lesser regular-vecs)
             (:last-lesser int-vecs)
             (:last-lesser long-vecs)
             (:last-lesser regular-vecs)
             (:rand-lesser-1 int-vecs)
             (:rand-lesser-1 long-vecs)
             (:rand-lesser-1 regular-vecs)
             (:rand-lesser-2 int-vecs)
             (:rand-lesser-2 long-vecs)
             (:rand-lesser-2 regular-vecs)
             (:rand-lesser-3 int-vecs)
             (:rand-lesser-3 long-vecs)
             (:rand-lesser-3 regular-vecs))
        (are [x] (= 1 (compare x int-vec))
             (:longer int-vecs)
             (:longer long-vecs)
             (:longer regular-vecs)
             (:first-greater int-vecs)
             (:first-greater long-vecs)
             (:first-greater regular-vecs)
             (:last-greater int-vecs)
             (:last-greater long-vecs)
             (:last-greater regular-vecs)
             (:rand-greater-1 int-vecs)
             (:rand-greater-1 long-vecs)
             (:rand-greater-1 regular-vecs)
             (:rand-greater-2 int-vecs)
             (:rand-greater-2 long-vecs)
             (:rand-greater-2 regular-vecs)
             (:rand-greater-3 int-vecs)
             (:rand-greater-3 long-vecs)
             (:rand-greater-3 regular-vecs))))
    (testing "Comparable.compareTo"
      (testing "incompatible"
        (is (thrown? NullPointerException (.compareTo int-vec nil)))
        (are [x] (thrown? ClassCastException (.compareTo int-vec x))
             '()
             {}
             #{}
             (sorted-set)
             (sorted-map)
             nums
             1))
      (testing "identical"
        (is (= 0 (.compareTo int-vec int-vec))))
      (testing "equivalent"
        (are [x] (= 0 (.compareTo int-vec x))
             (:standard long-vecs)
             (:standard regular-vecs)))
      (testing "lesser"
        (are [x] (= -1 (.compareTo int-vec x))
             (:longer int-vecs)
             (:longer long-vecs)
             (:longer regular-vecs)
             (:first-greater int-vecs)
             (:first-greater long-vecs)
             (:first-greater regular-vecs)
             (:last-greater int-vecs)
             (:last-greater long-vecs)
             (:last-greater regular-vecs)
             (:rand-greater-1 int-vecs)
             (:rand-greater-1 long-vecs)
             (:rand-greater-1 regular-vecs)
             (:rand-greater-2 int-vecs)
             (:rand-greater-2 long-vecs)
             (:rand-greater-2 regular-vecs)
             (:rand-greater-3 int-vecs)
             (:rand-greater-3 long-vecs)
             (:rand-greater-3 regular-vecs)))
      (testing "greater"
        (are [x] (= 1 (.compareTo int-vec x))
             (:empty int-vecs)
             (:empty long-vecs)
             (:empty regular-vecs)
             (:shorter int-vecs)
             (:shorter long-vecs)
             (:shorter regular-vecs)
             (:first-lesser int-vecs)
             (:first-lesser long-vecs)
             (:first-lesser regular-vecs)
             (:last-lesser int-vecs)
             (:last-lesser long-vecs)
             (:last-lesser regular-vecs)
             (:rand-lesser-1 int-vecs)
             (:rand-lesser-1 long-vecs)
             (:rand-lesser-1 regular-vecs)
             (:rand-lesser-2 int-vecs)
             (:rand-lesser-2 long-vecs)
             (:rand-lesser-2 regular-vecs)
             (:rand-lesser-3 int-vecs)
             (:rand-lesser-3 long-vecs)
             (:rand-lesser-3 regular-vecs))))))

(deftest test-vec-associative
  (let [empty-v (vector-of :long)
        v       (into empty-v (range 1 6))]
    (testing "Associative.containsKey"
      (are [x] (.containsKey v x)
           0 1 2 3 4)
      (are [x] (not (.containsKey v x))
           -1 -100 nil [] "" #"" #{} 5 100)
      (are [x] (not (.containsKey empty-v x))
           0 1))
    (testing "contains?"
      (are [x] (contains? v x)
           0 2 4)
      (are [x] (not (contains? v x))
           -1 -100 nil "" 5 100)
      (are [x] (not (contains? empty-v x))
           0 1))
    (testing "Associative.entryAt"
      (are [idx val] (= (clojure.lang.MapEntry. idx val)
                        (.entryAt v idx))
           0 1
           2 3
           4 5)
      (are [idx] (nil? (.entryAt v idx))
           -5 -1 5 10 nil "")
      (are [idx] (nil? (.entryAt empty-v idx))
           0 1))))

(deftest test-vec-creation
  (testing "Plain (vector-of :type)"
    (are [x] (and (empty? x) (instance? clojure.core.Vec x))
         (vector-of :boolean)
         (vector-of :byte)
         (vector-of :short)
         (vector-of :int)
         (vector-of :long)
         (vector-of :float)
         (vector-of :double)
         (vector-of :char))
    (testing "with invalid type argument"
      (are [x] (thrown? NullPointerException x)
           (vector-of nil)
           (vector-of Float/TYPE)
           (vector-of 'int)
           (vector-of ""))))
  (testing "vector-like (vector-of :type x1 x2 x3 … xn)"
    (are [vec gvec] (and (instance? clojure.core.Vec gvec)
                         (= (into (vector-of :int) vec) gvec)
                         (= vec gvec)
                         (= (hash vec) (hash gvec)))
         [1] (vector-of :int 1)
         [1 2] (vector-of :int 1 2)
         [1 2 3] (vector-of :int 1 2 3)
         [1 2 3 4] (vector-of :int 1 2 3 4)
         [1 2 3 4 5] (vector-of :int 1 2 3 4 5)
         [1 2 3 4 5 6] (vector-of :int 1 2 3 4 5 6)
         (apply vector (range 1000)) (apply vector-of :int (range 1000))
         [1 2 3] (vector-of :int 1M 2.0 3.1)
         [97 98 99] (vector-of :int \a \b \c))
    (testing "with null values"
      (are [x] (thrown? NullPointerException x)
        (vector-of :int nil)
        (vector-of :int 1 nil)
        (vector-of :int 1 2 nil)
        (vector-of :int 1 2 3 nil)
        (vector-of :int 1 2 3 4 nil)
        (vector-of :int 1 2 3 4 5 nil)
        (vector-of :int 1 2 3 4 5 6 nil)))
    (testing "with unsupported values"
      (are [x] (thrown? ClassCastException x)
           (vector-of :int true)
           (vector-of :int 1 2 3 4 5 false)
           (vector-of :int {:a 1 :b 2})
           (vector-of :int [1 2 3 4] [5 6])
           (vector-of :int '(1 2 3 4))
           (vector-of :int #{1 2 3 4})
           (vector-of :int (sorted-set 1 2 3 4))
           (vector-of :int 1 2 "3")
           (vector-of :int "1" "2" "3")))))

(deftest empty-vector-equality
  (let [colls [[] (vector-of :long) '()]]
    (doseq [c1 colls, c2 colls]
      (is (= c1 c2))
      (is (.equals c1 c2)))))

(defn =vec
  [expected v] (and (vector? v) (= expected v)))

(deftest test-mapv
  (are [r c1] (=vec r (mapv + c1))
       [1 2 3] [1 2 3])
  (are [r c1 c2] (=vec r (mapv + c1 c2))
       [2 3 4] [1 2 3] (repeat 1))
  (are [r c1 c2 c3] (=vec r (mapv + c1 c2 c3))
       [3 4 5] [1 2 3] (repeat 1) (repeat 1))
  (are [r c1 c2 c3 c4] (=vec r (mapv + c1 c2 c3 c4))
       [4 5 6] [1 2 3] [1 1 1] [1 1 1] [1 1 1]))

(deftest test-filterv
  (are [r c1] (=vec r (filterv even? c1))
       [] [1 3 5]
       [2 4] [1 2 3 4 5]))

(deftest test-subvec
  (let [v1 (vec (range 100))
        v2 (subvec v1 50 57)]
    (is (thrown? IndexOutOfBoundsException (v2 -1)))
    (is (thrown? IndexOutOfBoundsException (v2 7)))
    (is (= (v1 50) (v2 0)))
    (is (= (v1 56) (v2 6)))))

(deftest test-vec
  (is (= [1 2] (vec (first {1 2}))))
  (is (= [0 1 2 3] (vec [0 1 2 3])))
  (is (= [0 1 2 3] (vec (list 0 1 2 3))))
  (is (= [0 1 2 3] (vec (sorted-set 0 1 2 3))))
  (is (= [[1 2] [3 4]] (vec (sorted-map 1 2 3 4))))
  (is (= [0 1 2 3] (vec (range 4))))
  (is (= [\a \b \c \d] (vec "abcd")))
  (is (= [0 1 2 3] (vec (object-array (range 4)))))
  (is (= [1 2 3 4] (vec (eduction (map inc) (range 4)))))
  (is (= [0 1 2 3] (vec (reify clojure.lang.IReduceInit
                          (reduce [_ f start]
                            (reduce f start (range 4))))))))

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