Add convenience factory methods to create NSDictionary, NSArray, and NSSet

Frameworks/Core/ERExtensions/Sources/com/webobjects/foundation/NSArray.java

@@ -1058,6 +1058,50 @@ public static final <T> NSArray<T> emptyArray() {
 		return EmptyArray;
 	}
 
+	/**
+	 * Returns an immutable empty {@code NSArray}.
+	 *
+	 * @param <E>
+	 *            the {@code NSArray}'s element type
+	 * @return an empty {@code NSArray}
+	 */
+	public static <E> NSArray<E> of() {
+		return EmptyArray;
+	}
+
+	/**
+	 * Returns an immutable {@code NSArray} containing one element.
+	 *
+	 * @param <E>
+	 *            the {@code NSArray}'s element type
+	 * @param element
+	 *            the element to be contained in the array
+	 * @return a {@code NSArray} containing the specified element
+	 */
+	public static <E> NSArray<E> of(E element) {
+		return new NSArray<>(element);
+	}
+
+	/**
+	 * Returns an immutable {@code NSArray} containing an arbitrary number of elements.
+	 *
+	 * @param <E>
+	 *            the {@code NSArray}'s element type
+	 * @param elements
+	 *            the elements to be contained in the array
+	 * @return a {@code NSArray} containing the specified elements
+	 */
+	@SafeVarargs
+	public static <E> NSArray<E> of(E... elements) {
+		if (elements.length == 0) {
+			return EmptyArray;
+		} else if(elements.length == 1) {
+			return new NSArray(elements[0]);
+		}
+
+		return new NSArray<>(elements);
+	}
+
 	static {
 		try {
 			setOperatorForKey(CountOperatorName, new _CountOperator());

Frameworks/Core/ERExtensions/Sources/com/webobjects/foundation/NSDictionary.java

@@ -505,6 +505,167 @@ public static final <K, V> NSDictionary<K, V> emptyDictionary() {
 		return NSDictionary.EmptyDictionary;
 	}
 
+	/**
+	 * Returns an immutable {@code NSDictionary} containing zero entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return an empty {@code NSDictionary}
+	 */
+	public static <K, V> NSDictionary<K, V> of() {
+		return EmptyDictionary;
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing a single entry.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1) {
+		return dictionaryOfImpl(k1, v1);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing two entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2) {
+		return dictionaryOfImpl(k1, v1, k2, v2);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing three entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing four entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing five entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing six entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5, k6, v6);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing seven entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5, k6, v6, k7, v7);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing eight entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5, k6, v6, k7, v7, k8, v8);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing nine entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5, k6, v6, k7, v7, k8, v8, k9, v9);
+	}
+
+	/**
+	 * Returns an immutable {@code NSDictionary} containing ten entries.
+	 *
+	 * @param <K>the
+	 *            {@code NSDictionary}'s key type
+	 * @param <V>the
+	 *            {@code NSDictionary}'s value type
+	 * @return a {@code NSDictionary} containing the specified mapping
+	 */
+	public static <K, V> NSDictionary<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9, K k10, V v10) {
+		return dictionaryOfImpl(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5, k6, v6, k7, v7, k8, v8, k9, v9, k10, v10);
+	}
+
+	@SuppressWarnings("unchecked")
+	private static <K, V> NSDictionary<K, V> dictionaryOfImpl(Object... input) {
+		if(input.length == 2) {
+			return new NSDictionary<>((V) input[1], (K) input[0]);
+		}
+
+		int capacity = input.length / 2;
+		Object[] keys = new Object[capacity];
+		Object[] values = new Object[capacity];
+
+		for (int i = 0, j = 0; i < input.length; i += 2, j++) {
+			keys[j] = input[i];
+			values[j] = input[i + 1];
+		}
+
+		return new NSDictionary<>((V[])values, (K[]) keys);
+	}
+
 	public static Object decodeObject(NSCoder coder) {
 		int count = coder.decodeInt();
 		Object[] keys = new Object[count];

Frameworks/Core/ERExtensions/Sources/com/webobjects/foundation/NSSet.java

@@ -286,6 +286,50 @@ public void encodeWithCoder(NSCoder coder) {
 	public static <T> NSSet<T> emptySet() {
 		return (NSSet<T>) EmptySet;
 	}
+
+	/**
+	 * Returns an immutable empty {@code NSSet}.
+	 *
+	 * @param <E>
+	 *            the {@code NSSet}'s element type
+	 * @return an empty {@code NSSet}
+	 */
+	public static <E> NSSet<E> of() {
+		return EmptySet;
+	}
+
+	/**
+	 * Returns an immutable {@code NSSet} containing one element.
+	 *
+	 * @param <E>
+	 *            the {@code NSSet}'s element type
+	 * @param element
+	 *            the element to be contained in the array
+	 * @return a {@code NSSet} containing the specified element
+	 */
+	public static <E> NSSet<E> of(E element) {
+		return new NSSet<>(element);
+	}
+
+	/**
+	 * Returns an immutable {@code NSSet} containing an arbitrary number of elements.
+	 *
+	 * @param <E>
+	 *            the {@code NSSet}'s element type
+	 * @param elements
+	 *            the elements to be contained in the array
+	 * @return a {@code NSSet} containing the specified elements
+	 */
+	@SafeVarargs
+	public static <E> NSSet<E> of(E... elements) {
+		if (elements.length == 0) {
+			return EmptySet;
+		} else if(elements.length == 1) {
+			return new NSSet(elements[0]);
+		}
+
+		return new NSSet<>(elements);
+	}
 
 	@Override
 	public boolean equals(Object object) {

Tests/ERXTest/Sources/com/webobjects/foundation/NSArrayTest.java

@@ -1405,5 +1405,40 @@ public void testToArrayTArrayNull() {
     } catch (NullPointerException e) {
     }
   }
-
+
+  public void testCreateNSArrayOfZeroElements() {
+	 NSArray<?> array = NSArray.of();
+
+	 assertTrue(array.isEmpty());
+	 assertTrue(NSArray.EmptyArray == array);
+  }
+
+  public void testCreateNSArrayOfOneElement() {
+	 NSArray<String> array = NSArray.of("e1");
+
+	 assertEquals(1, array.size());
+	 assertEquals("e1", array.get(0));
+  }
+
+  public void testCreateNSArrayOfTwoElements() {
+	 NSArray<String> array = NSArray.of("e1", "e2");
+
+	 assertEquals(2, array.size());
+	 assertEquals("e1", array.get(0));
+	 assertEquals("e2", array.get(1));
+  }
+
+  public void testCreateNSArrayFromEmptyArray() {
+	 NSArray<String> array = NSArray.of(new String[] {});
+
+	 assertTrue(array.isEmpty());
+	 assertTrue(NSArray.EmptyArray == array);
+  }
+
+  public void testCreateNSArrayFromArrayWithOneElement() {
+	 NSArray<String> array = NSArray.of(new String[] { "e1" });
+
+	 assertEquals(1, array.size());
+	 assertEquals("e1", array.get(0));
+  }
 }