clojure-koans/src/koans/20_java_interop.clj

20 lines
662 B
Clojure

(ns koans.20-java-interop
(:require [koan-engine.core :refer :all]))
(meditations
"You may have done more with Java than you know"
(= __ (class "warfare")) ; hint: try typing (javadoc "warfare") in the REPL
"The dot signifies easy and direct Java interoperation"
(= __ (.toUpperCase "select * from"))
"But instance method calls are very different from normal functions"
(= ["SELECT" "FROM" "WHERE"] (map ___ ["select" "from" "where"]))
"Constructing might be harder than breaking"
(= 10 (let [latch (java.util.concurrent.CountDownLatch. __)]
(.getCount latch)))
"Static methods are slashing prices!"
(== __ (Math/pow 2 10)))