CustomHashSet now implements Set instead of Iterable

Author: andrei-punko

src/main/java/by/andd3dfx/collections/custom/CustomHashMap.java

@@ -26,7 +26,7 @@ public boolean isEmpty() {
         return size == 0;
     }
 
-    public V get(K key) {
+    public V get(Object key) {
         if (key == null) {
             return valueForNullKey;
         }
@@ -71,7 +71,7 @@ public V put(K key, V value) {
         return null;
     }
 
-    public boolean containsKey(K key) {
+    public boolean containsKey(Object key) {
         return get(key) != null;
     }
 
@@ -86,7 +86,7 @@ public boolean containsValue(V value) {
         return false;
     }
 
-    public V remove(K key) {
+    public V remove(Object key) {
         if (key == null) {
             var result = valueForNullKey;
             valueForNullKey = null;
@@ -122,7 +122,7 @@ Iterator<K> keyIterator() {
         return new KeyIterator<>(buckets);
     }
 
-    private int determineBucketNumber(K key) {
+    private int determineBucketNumber(Object key) {
         return Math.abs(key.hashCode() % BUCKETS_COUNT);
     }
 

src/main/java/by/andd3dfx/collections/custom/CustomHashSet.java

@@ -1,29 +1,41 @@
 package by.andd3dfx.collections.custom;
 
+import org.apache.commons.lang3.NotImplementedException;
+
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.Set;
 
 /**
  * @see <a href="https://youtu.be/aTbKxApYNYk">Video solution</a>
  */
-public class CustomHashSet<T> implements Iterable<T> {
+public class CustomHashSet<T> implements Set<T> {
 
-    private CustomHashMap<T, Object> map = new CustomHashMap<>();
+    private final CustomHashMap<T, Object> map = new CustomHashMap<>();
     private static final Object DUMMY_VALUE = new Object();
 
+    @Override
     public int size() {
         return map.size();
     }
 
+    @Override
     public boolean isEmpty() {
         return map.isEmpty();
     }
 
+    @Override
     public boolean add(T item) {
         return map.put(item, DUMMY_VALUE) == null;
     }
 
-    public boolean addAll(Collection<T> items) {
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends T> items) {
         boolean result = false;
         for (var item : items) {
             if (add(item)) {
@@ -33,11 +45,13 @@ public boolean addAll(Collection<T> items) {
         return result;
     }
 
-    public boolean remove(T item) {
+    @Override
+    public boolean remove(Object item) {
         return map.remove(item) == DUMMY_VALUE;
     }
 
-    public boolean removeAll(Collection<T> items) {
+    @Override
+    public boolean removeAll(Collection<?> items) {
         boolean result = false;
         for (var item : items) {
             if (remove(item)) {
@@ -47,11 +61,13 @@ public boolean removeAll(Collection<T> items) {
         return result;
     }
 
-    public boolean contains(T item) {
+    @Override
+    public boolean contains(Object item) {
         return map.containsKey(item);
     }
 
-    public boolean containsAll(Collection<T> items) {
+    @Override
+    public boolean containsAll(Collection<?> items) {
         for (var item : items) {
             if (!map.containsKey(item)) {
                 return false;
@@ -60,6 +76,7 @@ public boolean containsAll(Collection<T> items) {
         return true;
     }
 
+    @Override
     public void clear() {
         map.clear();
     }
@@ -69,13 +86,25 @@ public Iterator<T> iterator() {
         return map.keyIterator();
     }
 
+    @Override
+    public Object[] toArray() {
+        // TODO add implementation
+        throw new NotImplementedException();
+    }
+
+    @Override
+    public <T1> T1[] toArray(T1[] a) {
+        // TODO add implementation
+        throw new NotImplementedException();
+    }
+
     @Override
     public String toString() {
         StringBuilder sb = new StringBuilder();
         var it = iterator();
         while (it.hasNext()) {
             final T item = it.next();
-            sb.append(item + ", ");
+            sb.append(item).append(", ");
         }
         return "[" + sb.substring(0, sb.length() - 2) + "]";
     }

src/main/java/by/andd3dfx/collections/custom/CustomLinkedHashSet.java

@@ -19,10 +19,10 @@ public boolean add(T item) {
     }
 
     @Override
-    public boolean remove(T item) {
+    public boolean remove(Object item) {
         final boolean result = super.remove(item);
         if (result) {
-            linkedList.remove(item);
+            linkedList.remove((T) item);
         }
         return result;
     }