intraxia / jaxion

src/Contract/Axolotl/Collection.php

Indentation +314 added lines, -314 removed lines

@@ -9,318 +9,318 @@
 
 interface Collection extends Iterator, Countable, Serializes {
 
-	/**
-	 * Returns the type of the collection.
-	 *
-	 * @return string
-	 */
-	public function get_type();
-
-	/**
-	 * Returns a collection with $element added.
-	 *
-	 * @param  mixed $element
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function add( $element );
-
-	/**
-	 * Removes every element from the collection.
-	 *
-	 * @return Collection
-	 */
-	public function clear();
-
-	/**
-	 * Returns true if the collection contains any elements that satisfy
-	 * $condition, returns false if it contains none.
-	 *
-	 * @param callable $condition
-	 * @return bool
-	 */
-	public function contains( callable $condition );
-
-	/**
-	 * Returns the first element in the collection that satisfies
-	 * $condition, returns false if no such element exists.
-	 *
-	 * @param callable $condition
-	 * @return mixed
-	 */
-	public function find( callable $condition );
-
-	/**
-	 * Returns the index of the first element in the collection that satisfies
-	 * $condition, returns -1 if no such element exists.
-	 *
-	 * @param callable $condition
-	 * @return int
-	 */
-	public function find_index( callable $condition );
-
-	/**
-	 * Returns the element in the collection at $index.
-	 *
-	 * @param  int $index Index to get element from.
-	 * @return mixed
-	 * @throws OutOfRangeException
-	 */
-	public function at( $index );
-
-	/**
-	 * Returns true if $index is within the collection's range and returns false
-	 * if it is not.
-	 *
-	 * @param  int $index Index to check for existence.
-	 * @return bool
-	 * @throws InvalidArgumentException
-	 */
-	public function index_exists( $index );
-
-	/**
-	 * Returns the number of elements in the collection.
-	 *
-	 * @return int
-	 */
-	public function count();
-
-	/**
-	 * Returns a collection that only contains the elements which satisfy
-	 * $condition.
-	 *
-	 * @param callable $condition
-	 * @return Collection
-	 */
-	public function filter( callable $condition );
-
-	/**
-	 * Returns the last element in the collection that satisfies $condition,
-	 * returns false if no such element exists.
-	 *
-	 * @param callable $condition
-	 * @return mixed
-	 */
-	public function find_last( callable $condition );
-
-	/**
-	 * Returns the index of the last element in the collection that satisfies
-	 * $condition, returns -1 if no such element exists.
-	 *
-	 * @param callable $condition
-	 * @return int
-	 */
-	public function find_last_index( callable $condition );
-
-	/**
-	 * Returns a collection that contains the subset of elements ranging from the
-	 * index $start to $end.
-	 *
-	 * @param  int $start Begining index to slice from.
-	 * @param  int $end   End index to slice to.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function slice( $start, $end );
-
-	/**
-	 * Inserts $element at $index.
-	 *
-	 * @param int   $index     Index to start at.
-	 * @param mixed $element Element to insert.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 * @throws OutOfRangeException
-	 */
-	public function insert( $index, $element );
-
-	/**
-	 * Inserts the range $elements at $index.
-	 *
-	 * @param int   $index
-	 * @param array $elements
-	 * @return Collection
-	 * @throws OutOfRangeException
-	 */
-	public function insert_range( $index, array $elements );
-
-	/**
-	 * Removes all of the elements that satisfy $condition.
-	 *
-	 * @param  callable $condition
-	 * @return Collection
-	 */
-	public function without( callable $condition );
-
-	/**
-	 * Removes the element at $index.
-	 *
-	 * @param  int $index Index to remove.
-	 * @return Collection
-	 * @throws OutOfRangeException
-	 */
-	public function remove_at( $index );
-
-	/**
-	 * Reverses the order of the elements in the collection.
-	 *
-	 * @return Collection
-	 */
-	public function reverse();
-
-	/**
-	 * Sorts the elements in the collection using the user supplied comparison
-	 * function $callback.
-	 *
-	 * @param callable $callback
-	 * @return Collection
-	 */
-	public function sort( callable $callback );
-
-	/**
-	 * Returns an array containing the elements in the collection.
-	 *
-	 * @return array
-	 */
-	public function to_array();
-
-	/**
-	 * Iteratively reduces the collection to a single value using the callback
-	 * function $callable.
-	 *
-	 * @param callable $callable
-	 * @param null     $initial
-	 * @return mixed
-	 */
-	public function reduce( callable $callable, $initial = null );
-
-	/**
-	 * Returns true if every element in the collection satisfies $condition,
-	 * returns false if not.
-	 *
-	 * @param callable $condition
-	 * @return bool
-	 */
-	public function every( callable $condition );
-
-	/**
-	 * Removes all of the elements in the collection starting at index $num.
-	 *
-	 * @param  int $num Number of elements to drop.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function drop( $num );
-
-	/**
-	 * Removes all of the elements in the collectioin between index 0 and $num.
-	 *
-	 * @param int $num Number of elements to drop.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function drop_right( $num );
-
-	/**
-	 * Iteratively drops elements in the collection that satisfy $condition until
-	 * an element is encountered that does not satisfy $condition.
-	 *
-	 * @param callable $condition
-	 * @return Collection
-	 */
-	public function drop_while( callable $condition );
-
-	/**
-	 * Removes the first element in the collection.
-	 *
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function tail();
-
-	/**
-	 * Removes all of the elements in the collection starting at index $num.
-	 *
-	 * @param  int $num Number of elements to take.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function take( $num );
-
-	/**
-	 * Removes all of the elements in the collection before index $num.
-	 *
-	 * @param int $num Number of elements to take.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function take_right( $num );
-
-	/**
-	 * Iterates through the collection until an element is encountered that does
-	 * not satisfy $condition, then drops all of the elements starting at that
-	 * index.
-	 *
-	 * @param callable $condition
-	 * @return Collection
-	 */
-	public function take_while( callable $condition );
-
-	/**
-	 * Applies the callback function $callable to each element in the collection.
-	 *
-	 * @param callable $callable
-	 */
-	public function each( callable $callable );
-
-	/**
-	 * Returns a new instance of the collection with the callback function
-	 * $callable applied to each element.
-	 *
-	 * @param callable $callable
-	 * @return Collection
-	 */
-	public function map( callable $callable );
-
-	/**
-	 * Iteratively reduces the collection to a single value using the callback
-	 * function $callable starting at the rightmost index.
-	 *
-	 * @param callable $callable
-	 * @param null     $initial
-	 * @return mixed
-	 */
-	public function reduce_right( callable $callable, $initial = null );
-
-	/**
-	 * Randomly reorders the elements in the collection.
-	 *
-	 * @return Collection
-	 */
-	public function shuffle();
-
-	/**
-	 * Adds every member of $elements to the collection.
-	 *
-	 * @param array|Collection $elements Array of elements to merge.
-	 * @return Collection
-	 * @throws InvalidArgumentException
-	 */
-	public function merge( $elements );
-
-	/**
-	 * Get first element of the collection
-	 *
-	 * @return mixed
-	 * @throws OutOfBoundsException
-	 */
-	public function first();
-
-	/**
-	 * Get last element of the collection
-	 *
-	 * @return mixed
-	 * @throws OutOfBoundsException
-	 */
-	public function last();
+    /**
+     * Returns the type of the collection.
+     *
+     * @return string
+     */
+    public function get_type();
+
+    /**
+     * Returns a collection with $element added.
+     *
+     * @param  mixed $element
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function add( $element );
+
+    /**
+     * Removes every element from the collection.
+     *
+     * @return Collection
+     */
+    public function clear();
+
+    /**
+     * Returns true if the collection contains any elements that satisfy
+     * $condition, returns false if it contains none.
+     *
+     * @param callable $condition
+     * @return bool
+     */
+    public function contains( callable $condition );
+
+    /**
+     * Returns the first element in the collection that satisfies
+     * $condition, returns false if no such element exists.
+     *
+     * @param callable $condition
+     * @return mixed
+     */
+    public function find( callable $condition );
+
+    /**
+     * Returns the index of the first element in the collection that satisfies
+     * $condition, returns -1 if no such element exists.
+     *
+     * @param callable $condition
+     * @return int
+     */
+    public function find_index( callable $condition );
+
+    /**
+     * Returns the element in the collection at $index.
+     *
+     * @param  int $index Index to get element from.
+     * @return mixed
+     * @throws OutOfRangeException
+     */
+    public function at( $index );
+
+    /**
+     * Returns true if $index is within the collection's range and returns false
+     * if it is not.
+     *
+     * @param  int $index Index to check for existence.
+     * @return bool
+     * @throws InvalidArgumentException
+     */
+    public function index_exists( $index );
+
+    /**
+     * Returns the number of elements in the collection.
+     *
+     * @return int
+     */
+    public function count();
+
+    /**
+     * Returns a collection that only contains the elements which satisfy
+     * $condition.
+     *
+     * @param callable $condition
+     * @return Collection
+     */
+    public function filter( callable $condition );
+
+    /**
+     * Returns the last element in the collection that satisfies $condition,
+     * returns false if no such element exists.
+     *
+     * @param callable $condition
+     * @return mixed
+     */
+    public function find_last( callable $condition );
+
+    /**
+     * Returns the index of the last element in the collection that satisfies
+     * $condition, returns -1 if no such element exists.
+     *
+     * @param callable $condition
+     * @return int
+     */
+    public function find_last_index( callable $condition );
+
+    /**
+     * Returns a collection that contains the subset of elements ranging from the
+     * index $start to $end.
+     *
+     * @param  int $start Begining index to slice from.
+     * @param  int $end   End index to slice to.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function slice( $start, $end );
+
+    /**
+     * Inserts $element at $index.
+     *
+     * @param int   $index     Index to start at.
+     * @param mixed $element Element to insert.
+     * @return Collection
+     * @throws InvalidArgumentException
+     * @throws OutOfRangeException
+     */
+    public function insert( $index, $element );
+
+    /**
+     * Inserts the range $elements at $index.
+     *
+     * @param int   $index
+     * @param array $elements
+     * @return Collection
+     * @throws OutOfRangeException
+     */
+    public function insert_range( $index, array $elements );
+
+    /**
+     * Removes all of the elements that satisfy $condition.
+     *
+     * @param  callable $condition
+     * @return Collection
+     */
+    public function without( callable $condition );
+
+    /**
+     * Removes the element at $index.
+     *
+     * @param  int $index Index to remove.
+     * @return Collection
+     * @throws OutOfRangeException
+     */
+    public function remove_at( $index );
+
+    /**
+     * Reverses the order of the elements in the collection.
+     *
+     * @return Collection
+     */
+    public function reverse();
+
+    /**
+     * Sorts the elements in the collection using the user supplied comparison
+     * function $callback.
+     *
+     * @param callable $callback
+     * @return Collection
+     */
+    public function sort( callable $callback );
+
+    /**
+     * Returns an array containing the elements in the collection.
+     *
+     * @return array
+     */
+    public function to_array();
+
+    /**
+     * Iteratively reduces the collection to a single value using the callback
+     * function $callable.
+     *
+     * @param callable $callable
+     * @param null     $initial
+     * @return mixed
+     */
+    public function reduce( callable $callable, $initial = null );
+
+    /**
+     * Returns true if every element in the collection satisfies $condition,
+     * returns false if not.
+     *
+     * @param callable $condition
+     * @return bool
+     */
+    public function every( callable $condition );
+
+    /**
+     * Removes all of the elements in the collection starting at index $num.
+     *
+     * @param  int $num Number of elements to drop.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function drop( $num );
+
+    /**
+     * Removes all of the elements in the collectioin between index 0 and $num.
+     *
+     * @param int $num Number of elements to drop.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function drop_right( $num );
+
+    /**
+     * Iteratively drops elements in the collection that satisfy $condition until
+     * an element is encountered that does not satisfy $condition.
+     *
+     * @param callable $condition
+     * @return Collection
+     */
+    public function drop_while( callable $condition );
+
+    /**
+     * Removes the first element in the collection.
+     *
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function tail();
+
+    /**
+     * Removes all of the elements in the collection starting at index $num.
+     *
+     * @param  int $num Number of elements to take.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function take( $num );
+
+    /**
+     * Removes all of the elements in the collection before index $num.
+     *
+     * @param int $num Number of elements to take.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function take_right( $num );
+
+    /**
+     * Iterates through the collection until an element is encountered that does
+     * not satisfy $condition, then drops all of the elements starting at that
+     * index.
+     *
+     * @param callable $condition
+     * @return Collection
+     */
+    public function take_while( callable $condition );
+
+    /**
+     * Applies the callback function $callable to each element in the collection.
+     *
+     * @param callable $callable
+     */
+    public function each( callable $callable );
+
+    /**
+     * Returns a new instance of the collection with the callback function
+     * $callable applied to each element.
+     *
+     * @param callable $callable
+     * @return Collection
+     */
+    public function map( callable $callable );
+
+    /**
+     * Iteratively reduces the collection to a single value using the callback
+     * function $callable starting at the rightmost index.
+     *
+     * @param callable $callable
+     * @param null     $initial
+     * @return mixed
+     */
+    public function reduce_right( callable $callable, $initial = null );
+
+    /**
+     * Randomly reorders the elements in the collection.
+     *
+     * @return Collection
+     */
+    public function shuffle();
+
+    /**
+     * Adds every member of $elements to the collection.
+     *
+     * @param array|Collection $elements Array of elements to merge.
+     * @return Collection
+     * @throws InvalidArgumentException
+     */
+    public function merge( $elements );
+
+    /**
+     * Get first element of the collection
+     *
+     * @return mixed
+     * @throws OutOfBoundsException
+     */
+    public function first();
+
+    /**
+     * Get last element of the collection
+     *
+     * @return mixed
+     * @throws OutOfBoundsException
+     */
+    public function last();
 }

Spacing +27 added lines, -27 removed lines

@@ -23,7 +23,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function add( $element );
+	public function add($element);
 
 	/**
 	 * Removes every element from the collection.
@@ -39,7 +39,7 @@ 
 	 * @param callable $condition
 	 * @return bool
 	 */
-	public function contains( callable $condition );
+	public function contains(callable $condition);
 
 	/**
 	 * Returns the first element in the collection that satisfies
@@ -48,7 +48,7 @@ 
 	 * @param callable $condition
 	 * @return mixed
 	 */
-	public function find( callable $condition );
+	public function find(callable $condition);
 
 	/**
 	 * Returns the index of the first element in the collection that satisfies
@@ -57,7 +57,7 @@ 
 	 * @param callable $condition
 	 * @return int
 	 */
-	public function find_index( callable $condition );
+	public function find_index(callable $condition);
 
 	/**
 	 * Returns the element in the collection at $index.
@@ -66,7 +66,7 @@ 
 	 * @return mixed
 	 * @throws OutOfRangeException
 	 */
-	public function at( $index );
+	public function at($index);
 
 	/**
 	 * Returns true if $index is within the collection's range and returns false
@@ -76,7 +76,7 @@ 
 	 * @return bool
 	 * @throws InvalidArgumentException
 	 */
-	public function index_exists( $index );
+	public function index_exists($index);
 
 	/**
 	 * Returns the number of elements in the collection.
@@ -92,7 +92,7 @@ 
 	 * @param callable $condition
 	 * @return Collection
 	 */
-	public function filter( callable $condition );
+	public function filter(callable $condition);
 
 	/**
 	 * Returns the last element in the collection that satisfies $condition,
@@ -101,7 +101,7 @@ 
 	 * @param callable $condition
 	 * @return mixed
 	 */
-	public function find_last( callable $condition );
+	public function find_last(callable $condition);
 
 	/**
 	 * Returns the index of the last element in the collection that satisfies
@@ -110,7 +110,7 @@ 
 	 * @param callable $condition
 	 * @return int
 	 */
-	public function find_last_index( callable $condition );
+	public function find_last_index(callable $condition);
 
 	/**
 	 * Returns a collection that contains the subset of elements ranging from the
@@ -121,7 +121,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function slice( $start, $end );
+	public function slice($start, $end);
 
 	/**
 	 * Inserts $element at $index.
@@ -132,7 +132,7 @@ 
 	 * @throws InvalidArgumentException
 	 * @throws OutOfRangeException
 	 */
-	public function insert( $index, $element );
+	public function insert($index, $element);
 
 	/**
 	 * Inserts the range $elements at $index.
@@ -142,7 +142,7 @@ 
 	 * @return Collection
 	 * @throws OutOfRangeException
 	 */
-	public function insert_range( $index, array $elements );
+	public function insert_range($index, array $elements);
 
 	/**
 	 * Removes all of the elements that satisfy $condition.
@@ -150,7 +150,7 @@ 
 	 * @param  callable $condition
 	 * @return Collection
 	 */
-	public function without( callable $condition );
+	public function without(callable $condition);
 
 	/**
 	 * Removes the element at $index.
@@ -159,7 +159,7 @@ 
 	 * @return Collection
 	 * @throws OutOfRangeException
 	 */
-	public function remove_at( $index );
+	public function remove_at($index);
 
 	/**
 	 * Reverses the order of the elements in the collection.
@@ -175,7 +175,7 @@ 
 	 * @param callable $callback
 	 * @return Collection
 	 */
-	public function sort( callable $callback );
+	public function sort(callable $callback);
 
 	/**
 	 * Returns an array containing the elements in the collection.
@@ -192,7 +192,7 @@ 
 	 * @param null     $initial
 	 * @return mixed
 	 */
-	public function reduce( callable $callable, $initial = null );
+	public function reduce(callable $callable, $initial = null);
 
 	/**
 	 * Returns true if every element in the collection satisfies $condition,
@@ -201,7 +201,7 @@ 
 	 * @param callable $condition
 	 * @return bool
 	 */
-	public function every( callable $condition );
+	public function every(callable $condition);
 
 	/**
 	 * Removes all of the elements in the collection starting at index $num.
@@ -210,7 +210,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function drop( $num );
+	public function drop($num);
 
 	/**
 	 * Removes all of the elements in the collectioin between index 0 and $num.
@@ -219,7 +219,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function drop_right( $num );
+	public function drop_right($num);
 
 	/**
 	 * Iteratively drops elements in the collection that satisfy $condition until
@@ -228,7 +228,7 @@ 
 	 * @param callable $condition
 	 * @return Collection
 	 */
-	public function drop_while( callable $condition );
+	public function drop_while(callable $condition);
 
 	/**
 	 * Removes the first element in the collection.
@@ -245,7 +245,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function take( $num );
+	public function take($num);
 
 	/**
 	 * Removes all of the elements in the collection before index $num.
@@ -254,7 +254,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function take_right( $num );
+	public function take_right($num);
 
 	/**
 	 * Iterates through the collection until an element is encountered that does
@@ -264,14 +264,14 @@ 
 	 * @param callable $condition
 	 * @return Collection
 	 */
-	public function take_while( callable $condition );
+	public function take_while(callable $condition);
 
 	/**
 	 * Applies the callback function $callable to each element in the collection.
 	 *
 	 * @param callable $callable
 	 */
-	public function each( callable $callable );
+	public function each(callable $callable);
 
 	/**
 	 * Returns a new instance of the collection with the callback function
@@ -280,7 +280,7 @@ 
 	 * @param callable $callable
 	 * @return Collection
 	 */
-	public function map( callable $callable );
+	public function map(callable $callable);
 
 	/**
 	 * Iteratively reduces the collection to a single value using the callback
@@ -290,7 +290,7 @@ 
 	 * @param null     $initial
 	 * @return mixed
 	 */
-	public function reduce_right( callable $callable, $initial = null );
+	public function reduce_right(callable $callable, $initial = null);
 
 	/**
 	 * Randomly reorders the elements in the collection.
@@ -306,7 +306,7 @@ 
 	 * @return Collection
 	 * @throws InvalidArgumentException
 	 */
-	public function merge( $elements );
+	public function merge($elements);
 
 	/**
 	 * Get first element of the collection

src/Axolotl/Collection.php

Doc Comments +3 added lines, -3 removed lines

@@ -180,7 +180,7 @@ 
 	 *
 	 * @param  callable $condition Condition to satisfy.
 	 *
-	 * @return mixed
+	 * @return Collection
 	 */
 	public function filter( callable $condition ) {
 		$elements = array();
@@ -670,7 +670,7 @@ 
 	/**
 	 * Return the key of the current element.
 	 *
-	 * @return mixed
+	 * @return integer
 	 */
 	public function key() {
 		return $this->position;
@@ -697,7 +697,7 @@ 
 	 * from a trusted set of elements.
 	 *
 	 * @param array      $elements Array of elements to pass into new collection.
-	 * @param null|mixed $type
+	 * @param string $type
 	 *
 	 * @return static
 	 */

Indentation +735 added lines, -735 removed lines

@@ -15,739 +15,739 @@
  */
 class Collection implements CollectionContract {
 
-	/**
-	 * Collection elements.
-	 *
-	 * @var array
-	 */
-	protected $elements = array();
-
-	/**
-	 * Collection type to enforce.
-	 *
-	 * @var Type
-	 */
-	private $type;
-
-	/**
-	 * Where Collection is in loop.
-	 *
-	 * @var int
-	 */
-	protected $position = 0;
-
-	/**
-	 * Collection constructor.
-	 *
-	 * @param string $type
-	 * @param array  $elements
-	 */
-	public function __construct( $type, array $elements = array() ) {
-		$this->type = new Type( $type );
-
-		if ( $elements ) {
-			$this->type->validate_elements( $elements );
-		}
-
-		$this->elements = $elements;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return string
-	 */
-	public function get_type() {
-		return $this->type->get_type();
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param mixed $element
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function add( $element ) {
-		if ( $this->type->is_model() && is_array( $element ) ) {
-			$element = $this->type->create_model( $element );
-		}
-
-		$this->type->validate_element( $element );
-
-		$elements   = $this->elements;
-		$elements[] = $element;
-
-		$collection = new static( $this->get_type() );
-		$collection->set_from_trusted( $elements );
-
-		return $collection;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return Collection
-	 */
-	public function clear() {
-		return new static( $this->get_type() );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return bool
-	 */
-	public function contains( callable $condition ) {
-		return (bool) $this->find( $condition );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return mixed
-	 */
-	public function find( callable $condition ) {
-		$index = $this->find_index( $condition );
-
-		return -1 === $index ? false : $this->elements[ $index ];
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return int
-	 */
-	public function find_index( callable $condition ) {
-		$index = -1;
-
-		for ( $i = 0, $count = count( $this->elements ); $i < $count; $i++ ) {
-			if ( call_user_func( $condition, ($this->at( $i ) ) ) ) {
-				$index = $i;
-				break;
-			}
-		}
-
-		return $index;
-	}
-
-	/**
-	 * Fetches the element at the provided index.
-	 *
-	 * @param int $index Index to get element from.
-	 *
-	 * @return mixed
-	 *
-	 * @throws OutOfRangeException
-	 */
-	public function at( $index ) {
-		$this->validate_index( $index );
-
-		return $this->elements[ $index ];
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  int $index Index to check for existence.
-	 *
-	 * @return bool
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function index_exists( $index ) {
-		if ( ! is_int( $index ) ) {
-			throw new InvalidArgumentException( 'Index must be an integer' );
-		}
-
-		if ( $index < 0 ) {
-			throw new InvalidArgumentException( 'Index must be a non-negative integer' );
-		}
-
-		return $index < $this->count();
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return mixed
-	 */
-	public function filter( callable $condition ) {
-		$elements = array();
-
-		foreach ( $this->elements as $element ) {
-			if ( call_user_func( $condition, $element ) ) {
-				$elements[] = $element;
-			}
-		}
-
-		return $this->new_from_trusted( $elements );
-	}
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return mixed
-	 */
-	public function find_last( callable $condition ) {
-		$index = $this->find_last_index( $condition );
-
-		return -1 === $index ? null : $this->elements[ $index ];
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition
-	 * @return int
-	 */
-	public function find_last_index( callable $condition ) {
-		$index = -1;
-
-		for ( $i = count( $this->elements ) - 1; $i >= 0; $i-- ) {
-			if ( call_user_func( $condition, $this->elements[ $i ] ) ) {
-				$index = $i;
-				break;
-			}
-		}
-
-		return $index;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  int $start Begining index to slice from.
-	 * @param  int $end   End index to slice to.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function slice( $start, $end ) {
-		if ( $start < 0 || ! is_int( $start ) ) {
-			throw new InvalidArgumentException( 'Start must be a non-negative integer' );
-		}
-
-		if ( $end < 0 || ! is_int( $end ) ) {
-			throw new InvalidArgumentException( 'End must be a positive integer' );
-		}
-
-		if ( $start > $end ) {
-			throw new InvalidArgumentException( 'End must be greater than start' );
-		}
-
-		if ( $end > $this->count() + 1 ) {
-			throw new InvalidArgumentException( 'End must be less than the count of the items in the Collection' );
-		}
-
-		$length = $end - $start + 1;
-		$subset = array_slice( $this->elements, $start, $length );
-
-		$collection = new static($this->type);
-		$collection->set_from_trusted( $subset );
-
-		return $collection;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param int   $index     Index to start at.
-	 * @param mixed $element Element to insert.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 * @throws OutOfRangeException
-	 */
-	public function insert( $index, $element ) {
-		$this->validate_index( $index );
-		$this->type->validate_element( $element );
-
-		$a = array_slice( $this->elements, 0, $index );
-		$b = array_slice( $this->elements, $index, count( $this->elements ) );
-
-		$a[] = $element;
-
-		return $this->new_from_trusted( array_merge( $a, $b ) );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param int   $index    Index to start insertion at.
-	 * @param array $elements Elements in insert.
-	 *
-	 * @return Collection
-	 *
-	 * @throws OutOfRangeException
-	 */
-	public function insert_range( $index, array $elements ) {
-		$this->validate_index( $index );
-		$this->type->validate_elements( $elements );
-
-		// To work with negative index, get the positive relation to 0 index
-		$index < 0 && $index = $this->count() + $index + 1;
-
-		$partA = array_slice( $this->elements, 0, $index );
-		$partB = array_slice( $this->elements, $index, count( $this->elements ) );
-
-		$elements1 = array_merge( $partA, $elements );
-		$elements1 = array_merge( $elements1, $partB );
-
-		$col = new static( $this->type );
-		$col->set_from_trusted( $elements1 );
-
-		return $col;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  callable $condition Condition to satisfy.
-	 *
-	 * @return Collection
-	 */
-	public function without( callable $condition ) {
-		$inverse = function ( $element ) use ( $condition ) {
-			return ! call_user_func( $condition, $element );
-		};
-
-		return $this->filter( $inverse );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  int $index Index to remove.
-	 *
-	 * @return Collection
-	 *
-	 * @throws OutOfRangeException
-	 */
-	public function remove_at( $index ) {
-		$this->validate_index( $index );
-
-		$elements = $this->elements;
-
-		return $this->new_from_trusted(
-			array_merge(
-				array_slice( $elements, 0, $index ),
-				array_slice( $elements, $index + 1, count( $elements ) )
-			)
-		);
-	}
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return Collection
-	 */
-	public function reverse() {
-		return $this->new_from_trusted(
-			array_reverse( $this->elements )
-		);
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $callback Sort callback.
-	 *
-	 * @return Collection
-	 */
-	public function sort( callable $callback ) {
-		$elements = $this->elements;
-		usort( $elements, $callback );
-		return $this->new_from_trusted( $elements );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return array
-	 */
-	public function to_array() {
-		return $this->elements;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $callable Reducer function.
-	 *
-	 * @param null     $initial  Initial reducer value.
-	 *
-	 * @return mixed
-	 */
-	public function reduce( callable $callable, $initial = null ) {
-		return array_reduce( $this->elements, $callable, $initial );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $condition Condition callback.
-	 *
-	 * @return bool
-	 */
-	public function every( callable $condition ) {
-		$response = true;
-
-		foreach ( $this->elements as $element ) {
-			$result = call_user_func( $condition, $element );
-
-			if ( false === $result ) {
-				$response = false;
-				break;
-			}
-		}
-
-		return $response;
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  int $num Number of elements to drop.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function drop( $num ) {
-		return $this->slice( $num, $this->count() );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param int $num Number of elements to drop.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function drop_right( $num ) {
-		return $num !== $this->count()
-			? $this->slice( 0, $this->count() - $num - 1 )
-			: $this->clear();
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $condition Condition callback.
-	 *
-	 * @return Collection
-	 */
-	public function drop_while( callable $condition ) {
-		$count = $this->count_while_true( $condition );
-		return $count ? $this->drop( $count ) : $this;
-	}
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function tail() {
-		return $this->slice( 1, $this->count() );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param  int $num Number of elements to take.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function take( $num ) {
-		return $this->slice( 0, $num - 1 );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param int $num Number of elements to take.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function take_right( $num ) {
-		return $this->slice( $this->count() - $num, $this->count() );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $condition Callback function.
-	 *
-	 * @return Collection
-	 */
-	public function take_while( callable $condition ) {
-		$count = $this->count_while_true( $condition );
-
-		return $count ? $this->take( $count ) : $this->clear();
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $callable Callback function.
-	 */
-	public function each( callable $callable ) {
-		foreach ( $this->elements as $element ) {
-			call_user_func( $callable, $element );
-		}
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $callable Callback function.
-	 *
-	 * @return Collection
-	 */
-	public function map( callable $callable ) {
-		$elements = array();
-		$type = null;
-		foreach ( $this->elements as $element ) {
-			$result = call_user_func( $callable, $element );
-
-			if ( null === $type ) {
-				$type = gettype( $result );
-
-				if ( 'object' === $type ) {
-					$type = get_class( $result );
-				}
-			}
-
-			$elements[] = $result;
-		}
-
-		return $this->new_from_trusted( $elements, $type ? : $this->get_type() );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param callable $callable Reducer function.
-	 * @param null     $initial  Initial value.
-	 *
-	 * @return mixed
-	 */
-	public function reduce_right( callable $callable, $initial = null ) {
-		return array_reduce(
-			array_reverse( $this->elements ),
-			$callable,
-			$initial
-		);
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return Collection
-	 */
-	public function shuffle() {
-		$elements = $this->elements;
-		shuffle( $elements );
-
-		return $this->new_from_trusted( $elements );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @param array|Collection $elements Array of elements to merge.
-	 *
-	 * @return Collection
-	 *
-	 * @throws InvalidArgumentException
-	 */
-	public function merge( $elements ) {
-		if ( $elements instanceof static ) {
-			$elements = $elements->to_array();
-		}
-
-		if ( ! is_array( $elements ) ) {
-			throw new InvalidArgumentException( 'Merge must be given array or Collection' );
-		}
-
-		$this->type->validate_elements( $elements );
-
-		return $this->new_from_trusted(
-			array_merge( $this->elements, $elements )
-		);
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return mixed
-	 *
-	 * @throws OutOfBoundsException
-	 */
-	public function first() {
-		if ( empty( $this->elements ) ) {
-			throw new OutOfBoundsException( 'Cannot get first element of empty Collection' );
-		}
-
-		return reset( $this->elements );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return mixed
-	 *
-	 * @throws OutOfBoundsException
-	 */
-	public function last() {
-		if ( empty( $this->elements ) ) {
-			throw new OutOfBoundsException( 'Cannot get last element of empty Collection' );
-		}
-
-		return end( $this->elements );
-	}
-
-	/**
-	 * {@inheritdoc}
-	 *
-	 * @return int
-	 */
-	public function count() {
-		return count( $this->elements );
-	}
-
-	/**
-	 * {@inheritDoc}
-	 *
-	 * @return array
-	 */
-	public function serialize() {
-		return $this->map(function( $element ) {
-			if ( $element instanceof Serializes ) {
-				return $element->serialize();
-			}
-
-			return $element;
-		} )->to_array();
-	}
-
-	/**
-	 * Return the current element.
-	 *
-	 * @return mixed
-	 */
-	public function current() {
-		return $this->at( $this->position );
-	}
-
-	/**
-	 * Move forward to next element.
-	 */
-	public function next() {
-		$this->position ++;
-	}
-
-	/**
-	 * Return the key of the current element.
-	 *
-	 * @return mixed
-	 */
-	public function key() {
-		return $this->position;
-	}
-
-	/**
-	 * Checks if current position is valid.
-	 *
-	 * @return bool
-	 */
-	public function valid() {
-		return isset( $this->elements[ $this->position ] );
-	}
-
-	/**
-	 * Rewind the Iterator to the first element.
-	 */
-	public function rewind() {
-		$this->position = 0;
-	}
-
-	/**
-	 * Creates a new instance of the Collection
-	 * from a trusted set of elements.
-	 *
-	 * @param array      $elements Array of elements to pass into new collection.
-	 * @param null|mixed $type
-	 *
-	 * @return static
-	 */
-	protected function new_from_trusted( array $elements, $type = null ) {
-		$collection = new static( null !== $type ? $type : $this->get_type() );
-		$collection->set_from_trusted( $elements );
-
-		return $collection;
-	}
-
-	/**
-	 * Sets the elements without validating them.
-	 *
-	 * @param array $elements Pre-validated elements to set.
-	 */
-	protected function set_from_trusted( array $elements ) {
-		$this->elements = $elements;
-	}
-
-	/**
-	 * Number of elements true for the condition.
-	 *
-	 * @param callable $condition Condition to check.
-	 * @return int
-	 */
-	protected function count_while_true( callable $condition ) {
-		$count = 0;
-
-		foreach ( $this->elements as $element ) {
-			if ( ! $condition($element) ) {
-				break;
-			}
-			$count++;
-		}
-
-		return $count;
-	}
-
-	/**
-	 * Validates a number to be used as an index.
-	 *
-	 * @param  integer $index The number to be validated as an index.
-	 *
-	 * @throws OutOfRangeException
-	 */
-	protected function validate_index( $index ) {
-		$exists = $this->index_exists( $index );
-
-		if ( ! $exists ) {
-			throw new OutOfRangeException( 'Index out of bounds of collection' );
-		}
-	}
+    /**
+     * Collection elements.
+     *
+     * @var array
+     */
+    protected $elements = array();
+
+    /**
+     * Collection type to enforce.
+     *
+     * @var Type
+     */
+    private $type;
+
+    /**
+     * Where Collection is in loop.
+     *
+     * @var int
+     */
+    protected $position = 0;
+
+    /**
+     * Collection constructor.
+     *
+     * @param string $type
+     * @param array  $elements
+     */
+    public function __construct( $type, array $elements = array() ) {
+        $this->type = new Type( $type );
+
+        if ( $elements ) {
+            $this->type->validate_elements( $elements );
+        }
+
+        $this->elements = $elements;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return string
+     */
+    public function get_type() {
+        return $this->type->get_type();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param mixed $element
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function add( $element ) {
+        if ( $this->type->is_model() && is_array( $element ) ) {
+            $element = $this->type->create_model( $element );
+        }
+
+        $this->type->validate_element( $element );
+
+        $elements   = $this->elements;
+        $elements[] = $element;
+
+        $collection = new static( $this->get_type() );
+        $collection->set_from_trusted( $elements );
+
+        return $collection;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return Collection
+     */
+    public function clear() {
+        return new static( $this->get_type() );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return bool
+     */
+    public function contains( callable $condition ) {
+        return (bool) $this->find( $condition );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return mixed
+     */
+    public function find( callable $condition ) {
+        $index = $this->find_index( $condition );
+
+        return -1 === $index ? false : $this->elements[ $index ];
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return int
+     */
+    public function find_index( callable $condition ) {
+        $index = -1;
+
+        for ( $i = 0, $count = count( $this->elements ); $i < $count; $i++ ) {
+            if ( call_user_func( $condition, ($this->at( $i ) ) ) ) {
+                $index = $i;
+                break;
+            }
+        }
+
+        return $index;
+    }
+
+    /**
+     * Fetches the element at the provided index.
+     *
+     * @param int $index Index to get element from.
+     *
+     * @return mixed
+     *
+     * @throws OutOfRangeException
+     */
+    public function at( $index ) {
+        $this->validate_index( $index );
+
+        return $this->elements[ $index ];
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  int $index Index to check for existence.
+     *
+     * @return bool
+     *
+     * @throws InvalidArgumentException
+     */
+    public function index_exists( $index ) {
+        if ( ! is_int( $index ) ) {
+            throw new InvalidArgumentException( 'Index must be an integer' );
+        }
+
+        if ( $index < 0 ) {
+            throw new InvalidArgumentException( 'Index must be a non-negative integer' );
+        }
+
+        return $index < $this->count();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return mixed
+     */
+    public function filter( callable $condition ) {
+        $elements = array();
+
+        foreach ( $this->elements as $element ) {
+            if ( call_user_func( $condition, $element ) ) {
+                $elements[] = $element;
+            }
+        }
+
+        return $this->new_from_trusted( $elements );
+    }
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return mixed
+     */
+    public function find_last( callable $condition ) {
+        $index = $this->find_last_index( $condition );
+
+        return -1 === $index ? null : $this->elements[ $index ];
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition
+     * @return int
+     */
+    public function find_last_index( callable $condition ) {
+        $index = -1;
+
+        for ( $i = count( $this->elements ) - 1; $i >= 0; $i-- ) {
+            if ( call_user_func( $condition, $this->elements[ $i ] ) ) {
+                $index = $i;
+                break;
+            }
+        }
+
+        return $index;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  int $start Begining index to slice from.
+     * @param  int $end   End index to slice to.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function slice( $start, $end ) {
+        if ( $start < 0 || ! is_int( $start ) ) {
+            throw new InvalidArgumentException( 'Start must be a non-negative integer' );
+        }
+
+        if ( $end < 0 || ! is_int( $end ) ) {
+            throw new InvalidArgumentException( 'End must be a positive integer' );
+        }
+
+        if ( $start > $end ) {
+            throw new InvalidArgumentException( 'End must be greater than start' );
+        }
+
+        if ( $end > $this->count() + 1 ) {
+            throw new InvalidArgumentException( 'End must be less than the count of the items in the Collection' );
+        }
+
+        $length = $end - $start + 1;
+        $subset = array_slice( $this->elements, $start, $length );
+
+        $collection = new static($this->type);
+        $collection->set_from_trusted( $subset );
+
+        return $collection;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param int   $index     Index to start at.
+     * @param mixed $element Element to insert.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     * @throws OutOfRangeException
+     */
+    public function insert( $index, $element ) {
+        $this->validate_index( $index );
+        $this->type->validate_element( $element );
+
+        $a = array_slice( $this->elements, 0, $index );
+        $b = array_slice( $this->elements, $index, count( $this->elements ) );
+
+        $a[] = $element;
+
+        return $this->new_from_trusted( array_merge( $a, $b ) );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param int   $index    Index to start insertion at.
+     * @param array $elements Elements in insert.
+     *
+     * @return Collection
+     *
+     * @throws OutOfRangeException
+     */
+    public function insert_range( $index, array $elements ) {
+        $this->validate_index( $index );
+        $this->type->validate_elements( $elements );
+
+        // To work with negative index, get the positive relation to 0 index
+        $index < 0 && $index = $this->count() + $index + 1;
+
+        $partA = array_slice( $this->elements, 0, $index );
+        $partB = array_slice( $this->elements, $index, count( $this->elements ) );
+
+        $elements1 = array_merge( $partA, $elements );
+        $elements1 = array_merge( $elements1, $partB );
+
+        $col = new static( $this->type );
+        $col->set_from_trusted( $elements1 );
+
+        return $col;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  callable $condition Condition to satisfy.
+     *
+     * @return Collection
+     */
+    public function without( callable $condition ) {
+        $inverse = function ( $element ) use ( $condition ) {
+            return ! call_user_func( $condition, $element );
+        };
+
+        return $this->filter( $inverse );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  int $index Index to remove.
+     *
+     * @return Collection
+     *
+     * @throws OutOfRangeException
+     */
+    public function remove_at( $index ) {
+        $this->validate_index( $index );
+
+        $elements = $this->elements;
+
+        return $this->new_from_trusted(
+            array_merge(
+                array_slice( $elements, 0, $index ),
+                array_slice( $elements, $index + 1, count( $elements ) )
+            )
+        );
+    }
+    /**
+     * {@inheritdoc}
+     *
+     * @return Collection
+     */
+    public function reverse() {
+        return $this->new_from_trusted(
+            array_reverse( $this->elements )
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $callback Sort callback.
+     *
+     * @return Collection
+     */
+    public function sort( callable $callback ) {
+        $elements = $this->elements;
+        usort( $elements, $callback );
+        return $this->new_from_trusted( $elements );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return array
+     */
+    public function to_array() {
+        return $this->elements;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $callable Reducer function.
+     *
+     * @param null     $initial  Initial reducer value.
+     *
+     * @return mixed
+     */
+    public function reduce( callable $callable, $initial = null ) {
+        return array_reduce( $this->elements, $callable, $initial );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $condition Condition callback.
+     *
+     * @return bool
+     */
+    public function every( callable $condition ) {
+        $response = true;
+
+        foreach ( $this->elements as $element ) {
+            $result = call_user_func( $condition, $element );
+
+            if ( false === $result ) {
+                $response = false;
+                break;
+            }
+        }
+
+        return $response;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  int $num Number of elements to drop.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function drop( $num ) {
+        return $this->slice( $num, $this->count() );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param int $num Number of elements to drop.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function drop_right( $num ) {
+        return $num !== $this->count()
+            ? $this->slice( 0, $this->count() - $num - 1 )
+            : $this->clear();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $condition Condition callback.
+     *
+     * @return Collection
+     */
+    public function drop_while( callable $condition ) {
+        $count = $this->count_while_true( $condition );
+        return $count ? $this->drop( $count ) : $this;
+    }
+    /**
+     * {@inheritdoc}
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function tail() {
+        return $this->slice( 1, $this->count() );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param  int $num Number of elements to take.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function take( $num ) {
+        return $this->slice( 0, $num - 1 );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param int $num Number of elements to take.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function take_right( $num ) {
+        return $this->slice( $this->count() - $num, $this->count() );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $condition Callback function.
+     *
+     * @return Collection
+     */
+    public function take_while( callable $condition ) {
+        $count = $this->count_while_true( $condition );
+
+        return $count ? $this->take( $count ) : $this->clear();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $callable Callback function.
+     */
+    public function each( callable $callable ) {
+        foreach ( $this->elements as $element ) {
+            call_user_func( $callable, $element );
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $callable Callback function.
+     *
+     * @return Collection
+     */
+    public function map( callable $callable ) {
+        $elements = array();
+        $type = null;
+        foreach ( $this->elements as $element ) {
+            $result = call_user_func( $callable, $element );
+
+            if ( null === $type ) {
+                $type = gettype( $result );
+
+                if ( 'object' === $type ) {
+                    $type = get_class( $result );
+                }
+            }
+
+            $elements[] = $result;
+        }
+
+        return $this->new_from_trusted( $elements, $type ? : $this->get_type() );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param callable $callable Reducer function.
+     * @param null     $initial  Initial value.
+     *
+     * @return mixed
+     */
+    public function reduce_right( callable $callable, $initial = null ) {
+        return array_reduce(
+            array_reverse( $this->elements ),
+            $callable,
+            $initial
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return Collection
+     */
+    public function shuffle() {
+        $elements = $this->elements;
+        shuffle( $elements );
+
+        return $this->new_from_trusted( $elements );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param array|Collection $elements Array of elements to merge.
+     *
+     * @return Collection
+     *
+     * @throws InvalidArgumentException
+     */
+    public function merge( $elements ) {
+        if ( $elements instanceof static ) {
+            $elements = $elements->to_array();
+        }
+
+        if ( ! is_array( $elements ) ) {
+            throw new InvalidArgumentException( 'Merge must be given array or Collection' );
+        }
+
+        $this->type->validate_elements( $elements );
+
+        return $this->new_from_trusted(
+            array_merge( $this->elements, $elements )
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return mixed
+     *
+     * @throws OutOfBoundsException
+     */
+    public function first() {
+        if ( empty( $this->elements ) ) {
+            throw new OutOfBoundsException( 'Cannot get first element of empty Collection' );
+        }
+
+        return reset( $this->elements );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return mixed
+     *
+     * @throws OutOfBoundsException
+     */
+    public function last() {
+        if ( empty( $this->elements ) ) {
+            throw new OutOfBoundsException( 'Cannot get last element of empty Collection' );
+        }
+
+        return end( $this->elements );
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return int
+     */
+    public function count() {
+        return count( $this->elements );
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @return array
+     */
+    public function serialize() {
+        return $this->map(function( $element ) {
+            if ( $element instanceof Serializes ) {
+                return $element->serialize();
+            }
+
+            return $element;
+        } )->to_array();
+    }
+
+    /**
+     * Return the current element.
+     *
+     * @return mixed
+     */
+    public function current() {
+        return $this->at( $this->position );
+    }
+
+    /**
+     * Move forward to next element.
+     */
+    public function next() {
+        $this->position ++;
+    }
+
+    /**
+     * Return the key of the current element.
+     *
+     * @return mixed
+     */
+    public function key() {
+        return $this->position;
+    }
+
+    /**
+     * Checks if current position is valid.
+     *
+     * @return bool
+     */
+    public function valid() {
+        return isset( $this->elements[ $this->position ] );
+    }
+
+    /**
+     * Rewind the Iterator to the first element.
+     */
+    public function rewind() {
+        $this->position = 0;
+    }
+
+    /**
+     * Creates a new instance of the Collection
+     * from a trusted set of elements.
+     *
+     * @param array      $elements Array of elements to pass into new collection.
+     * @param null|mixed $type
+     *
+     * @return static
+     */
+    protected function new_from_trusted( array $elements, $type = null ) {
+        $collection = new static( null !== $type ? $type : $this->get_type() );
+        $collection->set_from_trusted( $elements );
+
+        return $collection;
+    }
+
+    /**
+     * Sets the elements without validating them.
+     *
+     * @param array $elements Pre-validated elements to set.
+     */
+    protected function set_from_trusted( array $elements ) {
+        $this->elements = $elements;
+    }
+
+    /**
+     * Number of elements true for the condition.
+     *
+     * @param callable $condition Condition to check.
+     * @return int
+     */
+    protected function count_while_true( callable $condition ) {
+        $count = 0;
+
+        foreach ( $this->elements as $element ) {
+            if ( ! $condition($element) ) {
+                break;
+            }
+            $count++;
+        }
+
+        return $count;
+    }
+
+    /**
+     * Validates a number to be used as an index.
+     *
+     * @param  integer $index The number to be validated as an index.
+     *
+     * @throws OutOfRangeException
+     */
+    protected function validate_index( $index ) {
+        $exists = $this->index_exists( $index );
+
+        if ( ! $exists ) {
+            throw new OutOfRangeException( 'Index out of bounds of collection' );
+        }
+    }
 }

Spacing +140 added lines, -140 removed lines

@@ -42,11 +42,11 @@ 
 	 * @param string $type
 	 * @param array  $elements
 	 */
-	public function __construct( $type, array $elements = array() ) {
-		$this->type = new Type( $type );
+	public function __construct($type, array $elements = array()) {
+		$this->type = new Type($type);
 
-		if ( $elements ) {
-			$this->type->validate_elements( $elements );
+		if ($elements) {
+			$this->type->validate_elements($elements);
 		}
 
 		$this->elements = $elements;
@@ -70,18 +70,18 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function add( $element ) {
-		if ( $this->type->is_model() && is_array( $element ) ) {
-			$element = $this->type->create_model( $element );
+	public function add($element) {
+		if ($this->type->is_model() && is_array($element)) {
+			$element = $this->type->create_model($element);
 		}
 
-		$this->type->validate_element( $element );
+		$this->type->validate_element($element);
 
 		$elements   = $this->elements;
 		$elements[] = $element;
 
-		$collection = new static( $this->get_type() );
-		$collection->set_from_trusted( $elements );
+		$collection = new static($this->get_type());
+		$collection->set_from_trusted($elements);
 
 		return $collection;
 	}
@@ -92,7 +92,7 @@ 
 	 * @return Collection
 	 */
 	public function clear() {
-		return new static( $this->get_type() );
+		return new static($this->get_type());
 	}
 
 	/**
@@ -102,8 +102,8 @@ 
 	 *
 	 * @return bool
 	 */
-	public function contains( callable $condition ) {
-		return (bool) $this->find( $condition );
+	public function contains(callable $condition) {
+		return (bool) $this->find($condition);
 	}
 
 	/**
@@ -113,10 +113,10 @@ 
 	 *
 	 * @return mixed
 	 */
-	public function find( callable $condition ) {
-		$index = $this->find_index( $condition );
+	public function find(callable $condition) {
+		$index = $this->find_index($condition);
 
-		return -1 === $index ? false : $this->elements[ $index ];
+		return -1 === $index ? false : $this->elements[$index];
 	}
 
 	/**
@@ -126,11 +126,11 @@ 
 	 *
 	 * @return int
 	 */
-	public function find_index( callable $condition ) {
+	public function find_index(callable $condition) {
 		$index = -1;
 
-		for ( $i = 0, $count = count( $this->elements ); $i < $count; $i++ ) {
-			if ( call_user_func( $condition, ($this->at( $i ) ) ) ) {
+		for ($i = 0, $count = count($this->elements); $i < $count; $i++) {
+			if (call_user_func($condition, ($this->at($i)))) {
 				$index = $i;
 				break;
 			}
@@ -148,10 +148,10 @@ 
 	 *
 	 * @throws OutOfRangeException
 	 */
-	public function at( $index ) {
-		$this->validate_index( $index );
+	public function at($index) {
+		$this->validate_index($index);
 
-		return $this->elements[ $index ];
+		return $this->elements[$index];
 	}
 
 	/**
@@ -163,13 +163,13 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function index_exists( $index ) {
-		if ( ! is_int( $index ) ) {
-			throw new InvalidArgumentException( 'Index must be an integer' );
+	public function index_exists($index) {
+		if (!is_int($index)) {
+			throw new InvalidArgumentException('Index must be an integer');
 		}
 
-		if ( $index < 0 ) {
-			throw new InvalidArgumentException( 'Index must be a non-negative integer' );
+		if ($index < 0) {
+			throw new InvalidArgumentException('Index must be a non-negative integer');
 		}
 
 		return $index < $this->count();
@@ -182,16 +182,16 @@ 
 	 *
 	 * @return mixed
 	 */
-	public function filter( callable $condition ) {
+	public function filter(callable $condition) {
 		$elements = array();
 
-		foreach ( $this->elements as $element ) {
-			if ( call_user_func( $condition, $element ) ) {
+		foreach ($this->elements as $element) {
+			if (call_user_func($condition, $element)) {
 				$elements[] = $element;
 			}
 		}
 
-		return $this->new_from_trusted( $elements );
+		return $this->new_from_trusted($elements);
 	}
 	/**
 	 * {@inheritdoc}
@@ -200,10 +200,10 @@ 
 	 *
 	 * @return mixed
 	 */
-	public function find_last( callable $condition ) {
-		$index = $this->find_last_index( $condition );
+	public function find_last(callable $condition) {
+		$index = $this->find_last_index($condition);
 
-		return -1 === $index ? null : $this->elements[ $index ];
+		return -1 === $index ? null : $this->elements[$index];
 	}
 
 	/**
@@ -212,11 +212,11 @@ 
 	 * @param  callable $condition
 	 * @return int
 	 */
-	public function find_last_index( callable $condition ) {
+	public function find_last_index(callable $condition) {
 		$index = -1;
 
-		for ( $i = count( $this->elements ) - 1; $i >= 0; $i-- ) {
-			if ( call_user_func( $condition, $this->elements[ $i ] ) ) {
+		for ($i = count($this->elements) - 1; $i >= 0; $i--) {
+			if (call_user_func($condition, $this->elements[$i])) {
 				$index = $i;
 				break;
 			}
@@ -235,28 +235,28 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function slice( $start, $end ) {
-		if ( $start < 0 || ! is_int( $start ) ) {
-			throw new InvalidArgumentException( 'Start must be a non-negative integer' );
+	public function slice($start, $end) {
+		if ($start < 0 || !is_int($start)) {
+			throw new InvalidArgumentException('Start must be a non-negative integer');
 		}
 
-		if ( $end < 0 || ! is_int( $end ) ) {
-			throw new InvalidArgumentException( 'End must be a positive integer' );
+		if ($end < 0 || !is_int($end)) {
+			throw new InvalidArgumentException('End must be a positive integer');
 		}
 
-		if ( $start > $end ) {
-			throw new InvalidArgumentException( 'End must be greater than start' );
+		if ($start > $end) {
+			throw new InvalidArgumentException('End must be greater than start');
 		}
 
-		if ( $end > $this->count() + 1 ) {
-			throw new InvalidArgumentException( 'End must be less than the count of the items in the Collection' );
+		if ($end > $this->count() + 1) {
+			throw new InvalidArgumentException('End must be less than the count of the items in the Collection');
 		}
 
 		$length = $end - $start + 1;
-		$subset = array_slice( $this->elements, $start, $length );
+		$subset = array_slice($this->elements, $start, $length);
 
 		$collection = new static($this->type);
-		$collection->set_from_trusted( $subset );
+		$collection->set_from_trusted($subset);
 
 		return $collection;
 	}
@@ -272,16 +272,16 @@ 
 	 * @throws InvalidArgumentException
 	 * @throws OutOfRangeException
 	 */
-	public function insert( $index, $element ) {
-		$this->validate_index( $index );
-		$this->type->validate_element( $element );
+	public function insert($index, $element) {
+		$this->validate_index($index);
+		$this->type->validate_element($element);
 
-		$a = array_slice( $this->elements, 0, $index );
-		$b = array_slice( $this->elements, $index, count( $this->elements ) );
+		$a = array_slice($this->elements, 0, $index);
+		$b = array_slice($this->elements, $index, count($this->elements));
 
 		$a[] = $element;
 
-		return $this->new_from_trusted( array_merge( $a, $b ) );
+		return $this->new_from_trusted(array_merge($a, $b));
 	}
 
 	/**
@@ -294,21 +294,21 @@ 
 	 *
 	 * @throws OutOfRangeException
 	 */
-	public function insert_range( $index, array $elements ) {
-		$this->validate_index( $index );
-		$this->type->validate_elements( $elements );
+	public function insert_range($index, array $elements) {
+		$this->validate_index($index);
+		$this->type->validate_elements($elements);
 
 		// To work with negative index, get the positive relation to 0 index
 		$index < 0 && $index = $this->count() + $index + 1;
 
-		$partA = array_slice( $this->elements, 0, $index );
-		$partB = array_slice( $this->elements, $index, count( $this->elements ) );
+		$partA = array_slice($this->elements, 0, $index);
+		$partB = array_slice($this->elements, $index, count($this->elements));
 
-		$elements1 = array_merge( $partA, $elements );
-		$elements1 = array_merge( $elements1, $partB );
+		$elements1 = array_merge($partA, $elements);
+		$elements1 = array_merge($elements1, $partB);
 
-		$col = new static( $this->type );
-		$col->set_from_trusted( $elements1 );
+		$col = new static($this->type);
+		$col->set_from_trusted($elements1);
 
 		return $col;
 	}
@@ -320,12 +320,12 @@ 
 	 *
 	 * @return Collection
 	 */
-	public function without( callable $condition ) {
-		$inverse = function ( $element ) use ( $condition ) {
-			return ! call_user_func( $condition, $element );
+	public function without(callable $condition) {
+		$inverse = function($element) use ($condition) {
+			return !call_user_func($condition, $element);
 		};
 
-		return $this->filter( $inverse );
+		return $this->filter($inverse);
 	}
 
 	/**
@@ -337,15 +337,15 @@ 
 	 *
 	 * @throws OutOfRangeException
 	 */
-	public function remove_at( $index ) {
-		$this->validate_index( $index );
+	public function remove_at($index) {
+		$this->validate_index($index);
 
 		$elements = $this->elements;
 
 		return $this->new_from_trusted(
 			array_merge(
-				array_slice( $elements, 0, $index ),
-				array_slice( $elements, $index + 1, count( $elements ) )
+				array_slice($elements, 0, $index),
+				array_slice($elements, $index + 1, count($elements))
 			)
 		);
 	}
@@ -356,7 +356,7 @@ 
 	 */
 	public function reverse() {
 		return $this->new_from_trusted(
-			array_reverse( $this->elements )
+			array_reverse($this->elements)
 		);
 	}
 
@@ -367,10 +367,10 @@ 
 	 *
 	 * @return Collection
 	 */
-	public function sort( callable $callback ) {
+	public function sort(callable $callback) {
 		$elements = $this->elements;
-		usort( $elements, $callback );
-		return $this->new_from_trusted( $elements );
+		usort($elements, $callback);
+		return $this->new_from_trusted($elements);
 	}
 
 	/**
@@ -391,8 +391,8 @@ 
 	 *
 	 * @return mixed
 	 */
-	public function reduce( callable $callable, $initial = null ) {
-		return array_reduce( $this->elements, $callable, $initial );
+	public function reduce(callable $callable, $initial = null) {
+		return array_reduce($this->elements, $callable, $initial);
 	}
 
 	/**
@@ -402,13 +402,13 @@ 
 	 *
 	 * @return bool
 	 */
-	public function every( callable $condition ) {
+	public function every(callable $condition) {
 		$response = true;
 
-		foreach ( $this->elements as $element ) {
-			$result = call_user_func( $condition, $element );
+		foreach ($this->elements as $element) {
+			$result = call_user_func($condition, $element);
 
-			if ( false === $result ) {
+			if (false === $result) {
 				$response = false;
 				break;
 			}
@@ -426,8 +426,8 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function drop( $num ) {
-		return $this->slice( $num, $this->count() );
+	public function drop($num) {
+		return $this->slice($num, $this->count());
 	}
 
 	/**
@@ -439,9 +439,9 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function drop_right( $num ) {
+	public function drop_right($num) {
 		return $num !== $this->count()
-			? $this->slice( 0, $this->count() - $num - 1 )
+			? $this->slice(0, $this->count() - $num - 1)
 			: $this->clear();
 	}
 
@@ -452,9 +452,9 @@ 
 	 *
 	 * @return Collection
 	 */
-	public function drop_while( callable $condition ) {
-		$count = $this->count_while_true( $condition );
-		return $count ? $this->drop( $count ) : $this;
+	public function drop_while(callable $condition) {
+		$count = $this->count_while_true($condition);
+		return $count ? $this->drop($count) : $this;
 	}
 	/**
 	 * {@inheritdoc}
@@ -464,7 +464,7 @@ 
 	 * @throws InvalidArgumentException
 	 */
 	public function tail() {
-		return $this->slice( 1, $this->count() );
+		return $this->slice(1, $this->count());
 	}
 
 	/**
@@ -476,8 +476,8 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function take( $num ) {
-		return $this->slice( 0, $num - 1 );
+	public function take($num) {
+		return $this->slice(0, $num - 1);
 	}
 
 	/**
@@ -489,8 +489,8 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function take_right( $num ) {
-		return $this->slice( $this->count() - $num, $this->count() );
+	public function take_right($num) {
+		return $this->slice($this->count() - $num, $this->count());
 	}
 
 	/**
@@ -500,10 +500,10 @@ 
 	 *
 	 * @return Collection
 	 */
-	public function take_while( callable $condition ) {
-		$count = $this->count_while_true( $condition );
+	public function take_while(callable $condition) {
+		$count = $this->count_while_true($condition);
 
-		return $count ? $this->take( $count ) : $this->clear();
+		return $count ? $this->take($count) : $this->clear();
 	}
 
 	/**
@@ -511,9 +511,9 @@ 
 	 *
 	 * @param callable $callable Callback function.
 	 */
-	public function each( callable $callable ) {
-		foreach ( $this->elements as $element ) {
-			call_user_func( $callable, $element );
+	public function each(callable $callable) {
+		foreach ($this->elements as $element) {
+			call_user_func($callable, $element);
 		}
 	}
 
@@ -524,24 +524,24 @@ 
 	 *
 	 * @return Collection
 	 */
-	public function map( callable $callable ) {
+	public function map(callable $callable) {
 		$elements = array();
 		$type = null;
-		foreach ( $this->elements as $element ) {
-			$result = call_user_func( $callable, $element );
+		foreach ($this->elements as $element) {
+			$result = call_user_func($callable, $element);
 
-			if ( null === $type ) {
-				$type = gettype( $result );
+			if (null === $type) {
+				$type = gettype($result);
 
-				if ( 'object' === $type ) {
-					$type = get_class( $result );
+				if ('object' === $type) {
+					$type = get_class($result);
 				}
 			}
 
 			$elements[] = $result;
 		}
 
-		return $this->new_from_trusted( $elements, $type ? : $this->get_type() );
+		return $this->new_from_trusted($elements, $type ?: $this->get_type());
 	}
 
 	/**
@@ -552,9 +552,9 @@ 
 	 *
 	 * @return mixed
 	 */
-	public function reduce_right( callable $callable, $initial = null ) {
+	public function reduce_right(callable $callable, $initial = null) {
 		return array_reduce(
-			array_reverse( $this->elements ),
+			array_reverse($this->elements),
 			$callable,
 			$initial
 		);
@@ -567,9 +567,9 @@ 
 	 */
 	public function shuffle() {
 		$elements = $this->elements;
-		shuffle( $elements );
+		shuffle($elements);
 
-		return $this->new_from_trusted( $elements );
+		return $this->new_from_trusted($elements);
 	}
 
 	/**
@@ -581,19 +581,19 @@ 
 	 *
 	 * @throws InvalidArgumentException
 	 */
-	public function merge( $elements ) {
-		if ( $elements instanceof static ) {
+	public function merge($elements) {
+		if ($elements instanceof static) {
 			$elements = $elements->to_array();
 		}
 
-		if ( ! is_array( $elements ) ) {
-			throw new InvalidArgumentException( 'Merge must be given array or Collection' );
+		if (!is_array($elements)) {
+			throw new InvalidArgumentException('Merge must be given array or Collection');
 		}
 
-		$this->type->validate_elements( $elements );
+		$this->type->validate_elements($elements);
 
 		return $this->new_from_trusted(
-			array_merge( $this->elements, $elements )
+			array_merge($this->elements, $elements)
 		);
 	}
 
@@ -605,11 +605,11 @@ 
 	 * @throws OutOfBoundsException
 	 */
 	public function first() {
-		if ( empty( $this->elements ) ) {
-			throw new OutOfBoundsException( 'Cannot get first element of empty Collection' );
+		if (empty($this->elements)) {
+			throw new OutOfBoundsException('Cannot get first element of empty Collection');
 		}
 
-		return reset( $this->elements );
+		return reset($this->elements);
 	}
 
 	/**
@@ -620,11 +620,11 @@ 
 	 * @throws OutOfBoundsException
 	 */
 	public function last() {
-		if ( empty( $this->elements ) ) {
-			throw new OutOfBoundsException( 'Cannot get last element of empty Collection' );
+		if (empty($this->elements)) {
+			throw new OutOfBoundsException('Cannot get last element of empty Collection');
 		}
 
-		return end( $this->elements );
+		return end($this->elements);
 	}
 
 	/**
@@ -633,7 +633,7 @@ 
 	 * @return int
 	 */
 	public function count() {
-		return count( $this->elements );
+		return count($this->elements);
 	}
 
 	/**
@@ -642,8 +642,8 @@ 
 	 * @return array
 	 */
 	public function serialize() {
-		return $this->map(function( $element ) {
-			if ( $element instanceof Serializes ) {
+		return $this->map(function($element) {
+			if ($element instanceof Serializes) {
 				return $element->serialize();
 			}
 
@@ -657,14 +657,14 @@ 
 	 * @return mixed
 	 */
 	public function current() {
-		return $this->at( $this->position );
+		return $this->at($this->position);
 	}
 
 	/**
 	 * Move forward to next element.
 	 */
 	public function next() {
-		$this->position ++;
+		$this->position++;
 	}
 
 	/**
@@ -682,7 +682,7 @@ 
 	 * @return bool
 	 */
 	public function valid() {
-		return isset( $this->elements[ $this->position ] );
+		return isset($this->elements[$this->position]);
 	}
 
 	/**
@@ -701,9 +701,9 @@ 
 	 *
 	 * @return static
 	 */
-	protected function new_from_trusted( array $elements, $type = null ) {
-		$collection = new static( null !== $type ? $type : $this->get_type() );
-		$collection->set_from_trusted( $elements );
+	protected function new_from_trusted(array $elements, $type = null) {
+		$collection = new static(null !== $type ? $type : $this->get_type());
+		$collection->set_from_trusted($elements);
 
 		return $collection;
 	}
@@ -713,7 +713,7 @@ 
 	 *
 	 * @param array $elements Pre-validated elements to set.
 	 */
-	protected function set_from_trusted( array $elements ) {
+	protected function set_from_trusted(array $elements) {
 		$this->elements = $elements;
 	}
 
@@ -723,11 +723,11 @@ 
 	 * @param callable $condition Condition to check.
 	 * @return int
 	 */
-	protected function count_while_true( callable $condition ) {
+	protected function count_while_true(callable $condition) {
 		$count = 0;
 
-		foreach ( $this->elements as $element ) {
-			if ( ! $condition($element) ) {
+		foreach ($this->elements as $element) {
+			if (!$condition($element)) {
 				break;
 			}
 			$count++;
@@ -743,11 +743,11 @@ 
 	 *
 	 * @throws OutOfRangeException
 	 */
-	protected function validate_index( $index ) {
-		$exists = $this->index_exists( $index );
+	protected function validate_index($index) {
+		$exists = $this->index_exists($index);
 
-		if ( ! $exists ) {
-			throw new OutOfRangeException( 'Index out of bounds of collection' );
+		if (!$exists) {
+			throw new OutOfRangeException('Index out of bounds of collection');
 		}
 	}
 }