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Java example source code file (vars.clj)

This example Java source code file (vars.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.

Learn more about this Java project at its project page.

Java - Java tags/keywords

author, eclipse, exception, frantisek, half_down, half_even, half_up, hickey, public, rich, sodomka, thread, unnecessary

The vars.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: Frantisek Sodomka, Stephen C. Gilardi


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

; http://clojure.org/vars

; def
; defn defn- defonce

; declare intern binding find-var var

(def ^:dynamic a)
(deftest test-binding
  (are [x y] (= x y)
      (eval `(binding [a 4] a)) 4     ; regression in Clojure SVN r1370
  ))

; var-get var-set alter-var-root [var? (predicates.clj)]
; with-in-str with-out-str
; with-open

(deftest test-with-local-vars
  (let [factorial (fn [x]
                    (with-local-vars [acc 1, cnt x]
                      (while (> @cnt 0)
                        (var-set acc (* @acc @cnt))
                        (var-set cnt (dec @cnt)))
                      @acc))]
    (is (= (factorial 5) 120))))

(deftest test-with-precision
  (are [x y] (= x y)
       (with-precision 4 (+ 3.5555555M 1)) 4.556M
       (with-precision 6 (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding CEILING     (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding FLOOR       (+ 3.5555555M 1)) 4.55555M
       (with-precision 6 :rounding HALF_UP     (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding HALF_DOWN   (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding HALF_EVEN   (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding UP          (+ 3.5555555M 1)) 4.55556M
       (with-precision 6 :rounding DOWN        (+ 3.5555555M 1)) 4.55555M
       (with-precision 6 :rounding UNNECESSARY (+ 3.5555M 1))    4.5555M))

(deftest test-settable-math-context
  (is (=
       (clojure.main/with-bindings
         (set! *math-context* (java.math.MathContext. 8))
         (+ 3.55555555555555M 1))
       4.5555556M)))

; set-validator get-validator

; doc find-doc test

(def stub-me :original)

(deftest test-with-redefs-fn
  (let [p (promise)]
    (with-redefs-fn {#'stub-me :temp}
      (fn []
        (.start (Thread. #(deliver p stub-me)))
        @p))
    (is (= :temp @p))
    (is (= :original stub-me))))

(deftest test-with-redefs
  (let [p (promise)]
    (with-redefs [stub-me :temp]
      (.start (Thread. #(deliver p stub-me)))
      @p)
    (is (= :temp @p))
    (is (= :original stub-me))))

(deftest test-with-redefs-throw
  (let [p (promise)]
    (is (thrown? Exception
      (with-redefs [stub-me :temp]
        (deliver p stub-me)
        (throw (Exception. "simulated failure in with-redefs")))))
    (is (= :temp @p))
    (is (= :original stub-me))))

(def ^:dynamic dynamic-var 1)

(deftest test-with-redefs-inside-binding
  (binding [dynamic-var 2]
    (is (= 2 dynamic-var))
    (with-redefs [dynamic-var 3]
      (is (= 2 dynamic-var))))
  (is (= 1 dynamic-var)))

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