Adds iterable interface

Author: patrickfav

CHANGELOG

@@ -4,6 +4,7 @@
 
 * add check method if transformer supports inplace
 * adds contains method
+* adds Iterable interface
 
 ## v0.4.1
 

README.md

@@ -288,6 +288,7 @@ Methods that return additional information about the instance.
 Finding occurrence of specific bytes:
 
 ```java
+Bytes.wrap(array).contains((byte) 0xE1);
 Bytes.wrap(array).indexOf((byte) 0xFD);
 Bytes.wrap(array).lastIndexOf((byte) 0xAE);
 ```
@@ -319,6 +320,15 @@ The `toString()` methods only shows the length and a preview of maximal 8 bytes:
 16 bytes (0x7ed1fdaa...12af000a)
 ```
 
+Bytes also implements the `Iterable` interface, so it can be used in a
+foreach loop:
+
+```java
+for (Byte aByte : bytesInstance) {
+    ...
+}
+```
+
 ### Validation
 
 A simple validation framework which can be used to check the internal byte array:

src/main/java/at/favre/lib/bytes/Bytes.java

@@ -24,6 +24,7 @@
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.InputStream;
+import java.io.Serializable;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
@@ -59,7 +60,7 @@
  * </pre>
  */
 @SuppressWarnings("WeakerAccess")
-public class Bytes implements Comparable<Bytes>, AbstractBytes {
+public class Bytes implements Comparable<Bytes>, AbstractBytes, Serializable, Iterable<Byte> {
 
     /* FACTORY ***************************************************************************************************/
 
@@ -1387,6 +1388,11 @@ public String toString() {
         return length() + " bytes " + preview;
     }
 
+    @Override
+    public Iterator<Byte> iterator() {
+        return new Util.BytesIterator(internalArray());
+    }
+
     /**
      * Internal factory for {@link Bytes} instances
      */
@@ -1397,4 +1403,5 @@ public Bytes wrap(byte[] array, ByteOrder byteOrder) {
         }
     }
 
+    static final long serialVersionUID = 1L;
 }

src/main/java/at/favre/lib/bytes/Util.java

@@ -322,7 +322,7 @@ static byte[] readFromFile(File file) {
      limitations under the License.
      =================================================================================================
      */
-    public static final class Entropy<T> {
+    static final class Entropy<T> {
         private final Map<T, Integer> map = new HashMap<>();
         private int total = 0;
 
@@ -349,4 +349,41 @@ public double entropy() {
             return entropy;
         }
     }
+
+    /**
+     * A simple iterator for the bytes class, which does not support remove
+     */
+    static final class BytesIterator implements Iterator<Byte> {
+        private final byte[] array;
+        /**
+         * Index of element to be returned by subsequent call to next.
+         */
+        private int cursor = 0;
+
+        BytesIterator(byte[] array) {
+            this.array = array;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return cursor != array.length;
+        }
+
+        @Override
+        public Byte next() {
+            try {
+                int i = cursor;
+                Byte next = array[i];
+                cursor = i + 1;
+                return next;
+            } catch (IndexOutOfBoundsException e) {
+                throw new NoSuchElementException();
+            }
+        }
+
+        @Override
+        public void remove() {
+            throw new UnsupportedOperationException("The Bytes iterator does not support removing");
+        }
+    }
 }

src/test/java/at/favre/lib/bytes/BytesMiscTest.java

@@ -25,6 +25,7 @@
 
 import java.nio.ByteOrder;
 import java.nio.ReadOnlyBufferException;
+import java.util.NoSuchElementException;
 
 import static org.junit.Assert.*;
 
@@ -254,4 +255,25 @@ public void readOnly() throws Exception {
         Bytes b = Bytes.from(example_bytes_twentyfour).readOnly();
         assertSame(b, b.readOnly());
     }
+
+    @Test
+    public void iteratorTest() throws Exception {
+        Bytes b = Bytes.wrap(example_bytes_seven);
+
+        int counter = 0;
+        for (Byte aByte : b) {
+            assertEquals((Byte) example_bytes_seven[counter], aByte);
+            counter++;
+        }
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void iteratorTestRemoveNotPossible() throws Exception {
+        Bytes.wrap(example_bytes_seven).iterator().remove();
+    }
+
+    @Test(expected = NoSuchElementException.class)
+    public void iteratorNoElement() throws Exception {
+        Bytes.allocate(0).iterator().next();
+    }
 }