Various minor changes and optimizations.

spec/loophp/collection/Iterator/CacheIteratorSpec.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace spec\loophp\collection\Iterator;
+
+use Iterator;
+use loophp\collection\Iterator\CacheIterator;
+use PhpSpec\ObjectBehavior;
+use Psr\Cache\CacheItemPoolInterface;
+
+class CacheIteratorSpec extends ObjectBehavior
+{
+    public function it_can_get_the_inner_iterator(Iterator $iterator, CacheItemPoolInterface $cache)
+    {
+        $this
+            ->beConstructedWith($iterator, $cache);
+
+        $this
+            ->getInnerIterator()
+            ->shouldReturn($iterator);
+    }
+
+    public function it_is_initializable(Iterator $iterator, CacheItemPoolInterface $cache)
+    {
+        $this->beConstructedWith($iterator, $cache);
+        $this->shouldHaveType(CacheIterator::class);
+    }
+}

src/Collection.php

@@ -466,9 +466,9 @@ public function last()
         return $this->transform(new Last());
     }
 
-    public function limit(int $limit): CollectionInterface
+    public function limit(int $limit, int $offset = 0): CollectionInterface
     {
-        return $this->run(new Limit($limit));
+        return $this->run(new Limit($limit, $offset));
     }
 
     public function loop(): CollectionInterface

src/Contract/Operation.php

@@ -10,13 +10,6 @@ interface Operation
 {
     public function __invoke(): Closure;
 
-    /**
-     * @param mixed|null $default
-     *
-     * @return mixed|null
-     */
-    public function get(string $key, $default = null);
-
     /**
      * @return array<string, mixed>
      */

src/Iterator/CacheIterator.php

@@ -15,7 +15,6 @@
  * @psalm-template T
  *
  * @implements \Iterator<TKey, T>
- * @implements \OuterIterator<TKey, T>
  */
 final class CacheIterator implements Iterator, OuterIterator
 {

src/Iterator/ClosureIterator.php

@@ -16,7 +16,6 @@
  *
  * @extends ProxyIterator<TKey, T>
  * @implements \Iterator<TKey, T>
- * @implements \OuterIterator<TKey, T>
  */
 final class ClosureIterator extends ProxyIterator implements Iterator, OuterIterator
 {

src/Iterator/IterableIterator.php

@@ -15,7 +15,6 @@
  *
  * @extends ProxyIterator<TKey, T>
  * @implements \Iterator<TKey, T>
- * @implements \OuterIterator<TKey, T>
  */
 final class IterableIterator extends ProxyIterator implements Iterator, OuterIterator
 {

src/Iterator/ResourceIterator.php

@@ -15,7 +15,6 @@
  *
  * @extends ProxyIterator<TKey, T>
  * @implements \Iterator<TKey, T>
- * @implements \OuterIterator<TKey, T>
  */
 final class ResourceIterator extends ProxyIterator implements Iterator, OuterIterator
 {

src/Iterator/StringIterator.php

@@ -15,7 +15,6 @@
  *
  * @extends ProxyIterator<TKey, T>
  * @implements \Iterator<TKey, T>
- * @implements \OuterIterator<TKey, T>
  */
 final class StringIterator extends ProxyIterator implements Iterator, OuterIterator
 {

src/Operation/AbstractOperation.php

@@ -4,27 +4,13 @@
 
 namespace loophp\collection\Operation;
 
-use function array_key_exists;
-
 abstract class AbstractOperation
 {
     /**
      * @var array<string, mixed>
      */
     protected $storage = [];
 
-    /**
-     * @param mixed|null $default
-     *
-     * @return mixed|null
-     */
-    public function get(string $key, $default = null)
-    {
-        return array_key_exists($key, $this->storage) ?
-            $this->storage[$key] :
-            $default;
-    }
-
     /**
      * @return array<string, mixed>
      */

src/Operation/Intersperse.php

@@ -26,8 +26,16 @@ final class Intersperse extends AbstractOperation implements Operation
      * @param mixed $element
      * @psalm-param T $element
      */
-    public function __construct($element, int $atEvery = 1, int $startAt = 0)
+    public function __construct($element, int $atEvery, int $startAt)
     {
+        if (0 > $atEvery) {
+            throw new InvalidArgumentException('The second parameter must be a positive integer.');
+        }
+
+        if (0 > $startAt) {
+            throw new InvalidArgumentException('The third parameter must be a positive integer.');
+        }
+
         $this->storage = [
             'element' => $element,
             'atEvery' => $atEvery,
@@ -37,19 +45,6 @@ public function __construct($element, int $atEvery = 1, int $startAt = 0)
 
     public function __invoke(): Closure
     {
-        /** @var int $every */
-        $every = $this->get('atEvery');
-        /** @var int $startAt */
-        $startAt = $this->get('startAt');
-
-        if (0 > $every) {
-            throw new InvalidArgumentException('The second parameter must be a positive integer.');
-        }
-
-        if (0 > $startAt) {
-            throw new InvalidArgumentException('The third parameter must be a positive integer.');
-        }
-
         return
             /**
              * @psalm-param \Iterator<TKey, T> $iterator

src/Operation/Random.php

@@ -17,7 +17,7 @@
  */
 final class Random extends AbstractOperation implements Operation
 {
-    public function __construct(int $size = 1)
+    public function __construct(int $size)
     {
         $this->storage = [
             'size' => $size,
@@ -33,7 +33,7 @@ public function __invoke(): Closure
              * @psalm-return \Generator<TKey, T>
              */
             static function (Iterator $iterator, int $size): Generator {
-                yield from (new Run(new Limit($size)))((new Run(new Shuffle()))($iterator));
+                yield from (new Run(new Limit($size), new Shuffle()))($iterator);
             };
     }
 }

src/Operation/Sort.php

@@ -63,7 +63,12 @@ static function (Iterator $iterator, int $type, callable $callback): Generator {
                      * @psalm-param array{TKey, T} $right
                      */
                     static function (array $left, array $right) use ($callback): int {
-                        return $callback(current($left), current($right));
+                        /** @psalm-var T $left */
+                        $left = current($left);
+                        /** @psalm-var T $right */
+                        $right = current($right);
+
+                        return $callback($left, $right);
                     };
 
                 $arrayIterator = new ArrayIterator(iterator_to_array((new Run(...$operations['before']))($iterator)));

src/Operation/Tail.php

@@ -33,10 +33,10 @@ public function __invoke(): Closure
             static function (Iterator $iterator, int $length): Generator {
                 return yield from (
                 new Run(
+                    new Skip(iterator_count($iterator) - $length),
                     new Limit($length)
-                ))(
-                    (new Run(new Skip(iterator_count($iterator) - $length)))($iterator)
-                );
+                )
+                )($iterator);
             };
     }
 }

src/Operation/Window.php

@@ -38,11 +38,9 @@ static function (Iterator $iterator, ArrayIterator $length): Generator {
 
                 for ($i = 0; iterator_count($iterator) > $i; ++$i) {
                     /** @psalm-var list<T> $window */
-                    $window = iterator_to_array((new Run(new Slice($i, $length->current())))($iterator));
+                    yield iterator_to_array((new Run(new Slice($i, $length->current())))($iterator));
 
                     $length->next();
-
-                    yield $window;
                 }
             };
     }

src/Transformation/Contains.php

@@ -21,15 +21,15 @@ final class Contains implements Transformation
      * @var ArrayIterator<int, mixed>
      * @psalm-var \ArrayIterator<int, T>
      */
-    private $value;
+    private $values;
 
     /**
-     * @param mixed ...$value
-     * @psalm-param T ...$value
+     * @param mixed ...$values
+     * @psalm-param T ...$values
      */
-    public function __construct(...$value)
+    public function __construct(...$values)
     {
-        $this->value = new ArrayIterator($value);
+        $this->values = new ArrayIterator($values);
     }
 
     /**
@@ -39,19 +39,20 @@ public function __construct(...$value)
      */
     public function __invoke(Iterator $collection)
     {
-        $value = $this->value;
-
-        return (new FoldLeft(
-            static function (bool $carry, $item, $key) use ($collection) {
-                $hasCallback = static function ($k, $v) use ($item) {
-                    return $item;
-                };
-
-                return ((new Transform(new Has($hasCallback)))($collection)) ?
-                    $carry :
-                    false;
-            },
-            true
-        ))($value);
+        $values = $this->values;
+
+        foreach ($collection as $key => $value) {
+            foreach ($values as $k => $v) {
+                if ($v === $value) {
+                    unset($values[$k]);
+                }
+
+                if (0 === $values->count()) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
     }
 }

src/Transformation/Implode.php

@@ -21,7 +21,7 @@ final class Implode implements Transformation
      */
     private $glue;
 
-    public function __construct(string $glue = '')
+    public function __construct(string $glue)
     {
         $this->glue = $glue;
     }