DesignPatternsPHP · domnikl · Sep 22, 2016 · Sep 21, 2016 · Sep 21, 2016 · Sep 21, 2016
diff --git a/.travis.yml b/.travis.yml
@@ -3,17 +3,10 @@ language: php
 sudo: false
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
-  - 5.6
   - 7.0
-  - hhvm
+  - 7.1
 
 matrix:
-  allow_failures:
-    - php: hhvm
-    - php: 7.0
   fast_finish: true
 
 cache:

diff --git a/Behavioral/Iterator/Book.php b/Behavioral/Iterator/Book.php
@@ -4,27 +4,33 @@
 
 class Book
 {
+    /**
+     * @var string
+     */
     private $author;
 
+    /**
+     * @var string
+     */
     private $title;
 
-    public function __construct($title, $author)
+    public function __construct(string $title, string $author)
     {
         $this->author = $author;
         $this->title = $title;
     }
 
-    public function getAuthor()
+    public function getAuthor(): string
     {
         return $this->author;
     }
 
-    public function getTitle()
+    public function getTitle(): string
     {
         return $this->title;
     }
 
-    public function getAuthorAndTitle()
+    public function getAuthorAndTitle(): string
     {
         return $this->getTitle().' by '.$this->getAuthor();
     }

diff --git a/Behavioral/Iterator/BookList.php b/Behavioral/Iterator/BookList.php
@@ -2,16 +2,17 @@
 
 namespace DesignPatterns\Behavioral\Iterator;
 
-class BookList implements \Countable
+class BookList implements \Countable, \Iterator
 {
-    private $books;
+    /**
+     * @var Book[]
+     */
+    private $books = [];
 
-    public function getBook($bookNumberToGet)
-    {
-        if (isset($this->books[$bookNumberToGet])) {
-            return $this->books[$bookNumberToGet];
-        }
-    }
+    /**
+     * @var int
+     */
+    private $currentIndex = 0;
 
     public function addBook(Book $book)
     {
@@ -21,15 +22,41 @@ public function addBook(Book $book)
     public function removeBook(Book $bookToRemove)
     {
         foreach ($this->books as $key => $book) {
-            /** @var Book $book */
             if ($book->getAuthorAndTitle() === $bookToRemove->getAuthorAndTitle()) {
                 unset($this->books[$key]);
             }
         }
+
+        $this->books = array_values($this->books);
     }
 
-    public function count()
+    public function count(): int
     {
         return count($this->books);
     }
+
+    public function current(): Book
+    {
+        return $this->books[$this->currentIndex];
+    }
+
+    public function key(): int
+    {
+        return $this->currentIndex;
+    }
+
+    public function next()
+    {
+        $this->currentIndex++;
+    }
+
+    public function rewind()
+    {
+        $this->currentIndex = 0;
+    }
+
+    public function valid(): bool
+    {
+        return isset($this->books[$this->currentIndex]);
+    }
 }
diff --git a/Behavioral/Iterator/BookListIterator.php b/Behavioral/Iterator/BookListIterator.php
diff --git a/Behavioral/Iterator/BookListReverseIterator.php b/Behavioral/Iterator/BookListReverseIterator.php
diff --git a/Behavioral/Iterator/README.rst b/Behavioral/Iterator/README.rst
@@ -4,8 +4,7 @@
 Purpose
 -------
 
-To make an object iterable and to make it appear like a collection of
-objects.
+To make an object iterable and to make it appear like a collection of objects.
 
 Examples
 --------
@@ -45,18 +44,6 @@ BookList.php
    :language: php
    :linenos:
 
-BookListIterator.php
-
-.. literalinclude:: BookListIterator.php
-   :language: php
-   :linenos:
-
-BookListReverseIterator.php
-
-.. literalinclude:: BookListReverseIterator.php
-   :language: php
-   :linenos:
-
 Test
 ----
 
@@ -67,4 +54,4 @@ Tests/IteratorTest.php
    :linenos:
 
 .. _`GitHub`: https://github.com/domnikl/DesignPatternsPHP/tree/master/Behavioral/Iterator
-.. __: http://en.wikipedia.org/wiki/Iterator_pattern
+.. __: http://en.wikipedia.org/wiki/Iterator_pattern