Okay, since you DO call the Clojure code from Java, I like what you did very much.
If you're running "edge" Clojure, and not 1.0, I'd recommend writing the tests in Clojure next, using the clojure.test namespace. Sean On Jul 9, 10:16 am, Patrik Fredriksson <[email protected]> wrote: > The idea is to gradually, over a few steps, move from a Java > implementation to a pure Clojure implementation. A this step the > Clojure implementation is called by the Java JUnit-test (see complete > test below). In the last step, the Java-references will be removed > from the Clojure implementation and the JUnit test replaced by Clojure > tests. > > The complete code, including Java, Groovy and current Clojure > implementation and a micro-benchmark, can be found > here:http://code.google.com/p/pnehm-java-to-cool-language-x/source/browse > > The complete JUnit test: > public class OrdererTestUsingJava extends TestCase { > > private void doTestOrderByFreq(Orderer orderer) { > List<String> unordered = Arrays.asList("b", "d", "b", "b", > "a", "c", "a"); > List<String> ordered = orderer.orderByFreq(unordered); > assertEquals(Arrays.asList("b", "a", "c", "d"), ordered); > > unordered = Arrays.asList("b", "d", "d", "e", "b", "a", "c", "a"); > ordered = orderer.orderByFreq(unordered); > assertEquals(Arrays.asList("a", "b", "d", "c", "e"), ordered); > > unordered = new ArrayList<String>(); > ordered = orderer.orderByFreq(unordered); > assertTrue(unordered.isEmpty()); > assertTrue(ordered.isEmpty()); > } > > public void testJavaImpl() { > doTestOrderByFreq(new JavaOrderer()); > } > > public void testClojureImpl() { > doTestOrderByFreq(new step3.pnehm.ClojureOrderer()); > } > > public void testGroovyImpl() { > doTestOrderByFreq(new GroovyOrderer()); > } > > } > > /Patrik > > On Thu, Jul 9, 2009 at 3:23 PM, Sean Devlin<[email protected]> wrote: > > > One question on design intent before feedback. Is your intent to have > > this Clojure code called by Java code later? > > > On Jul 9, 7:31 am, Patrik Fredriksson <[email protected]> wrote: > >> Hi! > > >> I started to look closer at Clojure after Rich Hickey's presentation > >> at QCon London in March, this is my first post. I spend my days > >> programming Java, but my journey as developer did actually start with > >> an ML programming course many years ago. It has been great fun to > >> re-discover the functional style of programming again! This list is a > >> great source of knowledge. > > >> A colleague of mine wrote an article about how to convert a piece of > >> Java code to Groovy a few months ago. As an exercise I thought I > >> should do the same, but to Clojure of course. I'd really appreciate > >> some feedback on the solution. I hope you aren't too sick of these > >> kind of posts just yet :-) > > >> The code orders a list of characters, first by frequency and then > >> alphabetically if two characters happen to have the same frequency. > > >> A Java unit test: > > >> private void doTestOrderByFreq(Orderer orderer) { > >> List<String> unordered = Arrays.asList("b", "d", "b", "b", > >> "a", "c", "a"); > >> List<String> ordered = orderer.orderByFreq(unordered); > >> assertEquals(Arrays.asList("b", "a", "c", "d"), ordered); > > >> } > > >> A Java implementation: > > >> public class JavaOrderer implements Orderer { > > >> public List<String> orderByFreq(List<String> in) { > >> final Bag bag = new HashBag(in); > >> List<String> out = new ArrayList<String>(bag.uniqueSet()); > > >> Collections.sort(out, new Comparator<String>() { > >> public int compare(String a, String b) { > >> int freq = Integer.valueOf( > >> bag.getCount(b)).compareTo(bag.getCount(a) > >> ); > >> return freq != 0 ? freq : a.compareTo(b); > >> } > >> }); > > >> return out; > >> } > > >> } > > >> My shot at a Clojure implementation, with inspiration from a previous > >> post in this group on a similar problem: > > >> (ns step3.pnehm.clojure-orderer > >> (:gen-class > >> :name step3.pnehm.ClojureOrderer > >> :implements [pnehm.Orderer] > >> )) > > >> (defn count-words [coll] > >> (reduce #(merge-with + %1 {%2 1}) {} coll)) > > >> (defn cmpr [[val1 freq1] [val2 freq2]] > >> (let [freq (compare freq2 freq1)] > >> (if (not= freq 0) freq (compare val1 val2)))) > > >> (defn -orderByFreq [_ coll] > >> (if (empty? coll) () (keys (sort cmpr (count-words coll))))) > > >> Orderer is a simple Java interface making it easy to call different > >> implementations from the JUnit test: > > >> List<String> orderByFreq(List<String> in); > > >> All kinds of feedback are welcome, both on style and the chosen solution. > > >> Many thanks! > > >> /Patrik --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. 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