Added toList(), toStream(), toOption() and toArray() to HashMap

pawelkrupinski · pawelkrupinski · commit 25eb247b57c0 · 2012-05-15T23:36:05.000+01:00
diff --git a/core/src/main/java/fj/data/HashMap.java b/core/src/main/java/fj/data/HashMap.java
@@ -1,16 +1,16 @@
 package fj.data;
 
+import fj.Equal;
 import fj.F;
-import static fj.P.p;
-
 import fj.Hash;
 import fj.P2;
-import static fj.data.Option.fromNull;
-import fj.Equal;
 
 import java.util.Collection;
 import java.util.Iterator;
 
+import static fj.P.p;
+import static fj.data.Option.fromNull;
+
 /**
  * A mutable hash map providing O(1) lookup.
  *
@@ -243,16 +243,32 @@ public Option<V> getDelete(final K k) {
     return fromNull(m.remove(new Key<K>(k, e, h)));
   }
 
+  public List<P2<K, V>> toList() {
+    return keys().map(new F<K, P2<K, V>>() {
+      public P2<K, V> f(final K k) {
+        return p(k, get(k).some());
+      }
+    });
+  }
+
   /**
    * Projects an immutable collection of this hash map.
    *
    * @return An immutable collection of this hash map.
    */
   public Collection<P2<K, V>> toCollection() {
-    return keys().map(new F<K, P2<K, V>>() {
-      public P2<K, V> f(final K k) {
-        return p(k, get(k).some());
-      }
-    }).toCollection();
+    return toList().toCollection();
+  }
+
+  public Stream<P2<K, V>> toStream() {
+    return toList().toStream();
+  }
+
+  public Option<P2<K, V>> toOption() {
+    return toList().toOption();
+  }
+
+  public Array<P2<K, V>> toArray() {
+    return toList().toArray();
   }
 }
diff --git a/core/src/test/fj/data/CheckHashMap.scala b/core/src/test/fj/data/CheckHashMap.scala
@@ -6,6 +6,8 @@ import ArbitraryHashMap._
 import Equal.{intEqual, stringEqual, optionEqual}
 import Hash.{intHash, stringHash}
 import org.scalacheck.Properties
+import fj.Equal._
+import fj.data.Option._
 
 object CheckHashMap extends Properties("HashMap") {
   implicit val equalInt: Equal[Int] = intEqual comap ((x: Int) => (x: java.lang.Integer))
@@ -40,6 +42,12 @@ object CheckHashMap extends Properties("HashMap") {
     m.get(k).isNone
   })
 
+  property("toList") = forAll((m: HashMap[Int, String]) => {
+    val list = m.toList
+    list.length() == m.keys().length() && list.forall((entry: P2[Int, String]) =>
+        optionEqual(stringEqual).eq(m.get(entry._1()), some(entry._2())).asInstanceOf[java.lang.Boolean])
+  })
+
   property("getDelete") = forAll((m: HashMap[Int, String], k: Int) => {
     val x = m.get(k)
     val y = m.getDelete(k)
