README.md

@@ -178,21 +178,22 @@ the methods always return the same values for the same inputs.
 
 | Methods       | Return type           | Source         |
 | ------------- | --------------------- | -------------- |
-| `all`         | array                 | [Collection.php](./src/Collection.php)
+| `all`         | array                 | [All.php](./src/Operation/All.php)
 | `append`      | new Collection object | [Append.php](./src/Operation/Append.php)
 | `apply`       | self                  | [Apply.php](./src/Operation/Apply.php)
 | `chunk`       | new Collection object | [Chunk.php](./src/Operation/Chunk.php)
 | `collapse`    | new Collection object | [Collapse.php](./src/Operation/Collapse.php)
 | `combine`     | new Collection object | [Combine.php](./src/Operation/Combine.php)
-| `count`       | int                   | [Collection.php](./src/Collection.php)
+| `count`       | int                   | [Count.php](./src/Operation/Count.php)
 | `filter`      | new Collection object | [Filter.php](./src/Operation/Filter.php)
-| `first`       | mixed                 | [Collection.php](./src/Collection.php)
+| `first`       | mixed                 | [First.php](./src/Operation/First.php)
 | `flatten`     | new Collection object | [Flatten.php](./src/Operation/Flatten.php)
 | `flip`        | new Collection object | [Flip.php](./src/Operation/Flip.php)
 | `forget`      | new Collection object | [Forget.php](./src/Operation/Forget.php)
-| `get`         | mixed                 | [Collection.php](./src/Collection.php)
+| `get`         | mixed                 | [Get.php](./src/Operation/Get.php)
 | `getIterator` | Iterator              | [Collection.php](./src/Collection.php)
 | `keys`        | new Collection object | [Keys.php](./src/Operation/Keys.php)
+| `last`        | mixed                 | [Last.php](./src/Operation/Last.php)
 | `limit`       | new Collection object | [Limit.php](./src/Operation/Limit.php)
 | `map`         | new Collection object | [Map.php](./src/Operation/Map.php)
 | `merge`       | new Collection object | [Merge.php](./src/Operation/Merge.php)
@@ -204,10 +205,11 @@ the methods always return the same values for the same inputs.
 | `prepend`     | new Collection object | [Prepend.php](./src/Operation/Prepend.php)
 | `proxy`       | new Collection object | [Proxy.php](./src/Operation/Proxy.php)
 | `rebase`      | new Collection object | [Rebase.php](./src/Operation/Rebase.php)
-| `reduce`      | mixed                 | [Collection.php](./src/Collection.php)
+| `reduce`      | mixed                 | [Reduce.php](./src/Operation/Reduce.php)
 | `run`         | mixed                 | [Run.php](./src/Operation/Run.php)
 | `skip`        | new Collection object | [Skip.php](./src/Operation/Skip.php)
 | `slice`       | new Collection object | [Slice.php](./src/Operation/Slice.php)
+| `sort `       | new Collection object | [Sort.php](./src/Operation/Sort.php)
 | `walk`        | new Collection object | [Walk.php](./src/Operation/Walk.php)
 | `zip`         | new Collection object | [Zip.php](./src/Operation/Zip.php)
 

spec/drupol/collection/CollectionSpec.php

@@ -472,6 +472,20 @@ static function ($value) {
             ->shouldBe(null);
     }
 
+    public function it_can_get_the_last_item(): void
+    {
+        $this
+            ->beConstructedThrough('with', [\range('A', 'F')]);
+
+        $this
+            ->last()
+            ->shouldReturn('F');
+
+        $this::with([])
+            ->last()
+            ->shouldReturn(null);
+    }
+
     public function it_can_keys(): void
     {
         $this
@@ -763,6 +777,21 @@ public function it_can_slice(): void
             ->shouldIterateAs([5 => 5, 6 => 6, 7 => 7, 8 => 8, 9 => 9, 10 => 10]);
     }
 
+    public function it_can_sort(): void
+    {
+        $input = \range('A', 'E');
+        $input = \array_combine($input, $input);
+
+        $this
+            ->beConstructedThrough('with', [$input]);
+
+        $this
+            ->sort(static function ($item1, $item2) {
+                return $item2 <=> $item1;
+            })
+            ->shouldIterateAs(['E' => 'E', 'D' => 'D', 'C' => 'C', 'B' => 'B', 'A' => 'A']);
+    }
+
     public function it_can_use_range(): void
     {
         $this

src/Collection.php

@@ -15,13 +15,15 @@
 use drupol\collection\Operation\Collapse;
 use drupol\collection\Operation\Combine;
 use drupol\collection\Operation\Contains;
+use drupol\collection\Operation\Count;
 use drupol\collection\Operation\Filter;
 use drupol\collection\Operation\First;
 use drupol\collection\Operation\Flatten;
 use drupol\collection\Operation\Flip;
 use drupol\collection\Operation\Forget;
 use drupol\collection\Operation\Get;
 use drupol\collection\Operation\Keys;
+use drupol\collection\Operation\Last;
 use drupol\collection\Operation\Limit;
 use drupol\collection\Operation\Merge;
 use drupol\collection\Operation\Normalize;
@@ -37,6 +39,7 @@
 use drupol\collection\Operation\Run;
 use drupol\collection\Operation\Skip;
 use drupol\collection\Operation\Slice;
+use drupol\collection\Operation\Sort;
 use drupol\collection\Operation\Walk;
 use drupol\collection\Operation\Zip;
 use Traversable;
@@ -112,7 +115,7 @@ public function contains($key): bool
      */
     public function count(): int
     {
-        return \iterator_count($this->getIterator());
+        return $this->run(Count::with());
     }
 
     /**
@@ -126,9 +129,9 @@ public static function empty(): CollectionInterface
     /**
      * {@inheritdoc}
      */
-    public function filter(callable $callback = null): CollectionInterface
+    public function filter(callable ...$callbacks): CollectionInterface
     {
-        return $this->run(Filter::with($callback));
+        return $this->run(Filter::with($callbacks));
     }
 
     /**
@@ -187,6 +190,14 @@ public function keys(): CollectionInterface
         return $this->run(Keys::with());
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function last()
+    {
+        return $this->run(Last::with());
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -321,6 +332,14 @@ public function slice(int $offset, int $length = null): CollectionInterface
         return $this->run(Slice::with($offset, $length));
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function sort(callable $callback): CollectionInterface
+    {
+        return $this->run(Sort::with($callback));
+    }
+
     /**
      * Create a new instance by invoking the callback a given amount of times.
      *
@@ -357,11 +376,11 @@ public function walk(callable ...$callbacks): CollectionInterface
     /**
      * Create a new collection instance.
      *
-     * @param null|array|callable|Closure|CollectionInterface|\Iterator $data
+     * @param array|callable|Closure|CollectionInterface|\Iterator $data
      *
      * @return \drupol\collection\Contract\Collection
      */
-    public static function with($data = []): CollectionInterface
+    public static function with($data): CollectionInterface
     {
         if ($data instanceof Closure || \is_callable($data)) {
             return self::withClosure($data);

src/Contract/Collection.php

@@ -75,11 +75,11 @@ public function count(): int;
     /**
      * Run a filter over each of the items.
      *
-     * @param null|callable $callback
+     * @param callable ...$callbacks
      *
      * @return \drupol\collection\Contract\Collection
      */
-    public function filter(callable $callback = null): self;
+    public function filter(callable ...$callbacks): self;
 
     /**
      * Get the first item from the collection passing the given truth test.
@@ -142,6 +142,13 @@ public function getIterator();
      */
     public function keys(): self;
 
+    /**
+     * Get the last item.
+     *
+     * @return mixed
+     */
+    public function last();
+
     /**
      * Limit the first {$limit} items.
      *
@@ -249,7 +256,7 @@ public function reduce(callable $callback, $initial = null);
     /**
      * @param \drupol\collection\Contract\Operation ...$operations
      *
-     * @return bool|mixed
+     * @return bool|int|mixed
      */
     public function run(Operation ...$operations);
 
@@ -272,6 +279,15 @@ public function skip(int ...$counts): self;
      */
     public function slice(int $offset, int $length = null): self;
 
+    /**
+     * Sort the collection using a callback.
+     *
+     * @param callable $callable
+     *
+     * @return \drupol\collection\Contract\Collection
+     */
+    public function sort(callable $callable): self;
+
     /**
      * @param callable ...$callbacks
      *

src/Operation/Append.php

@@ -20,7 +20,8 @@ public function run(CollectionInterface $collection): CollectionInterface
         [$items] = $this->parameters;
 
         return Collection::with(
-            static function () use ($items, $collection) {
+            static function () use ($items, $collection): \Generator
+            {
                 foreach ($collection as $item) {
                     yield $item;
                 }

src/Operation/Chunk.php

@@ -20,11 +20,12 @@ public function run(CollectionInterface $collection): CollectionInterface
         $size = $this->parameters[0];
 
         if (0 >= $size) {
-            return Collection::with();
+            return Collection::empty();
         }
 
         return Collection::with(
-            static function () use ($size, $collection) {
+            static function () use ($size, $collection): \Generator
+            {
                 $iterator = $collection->getIterator();
 
                 while ($iterator->valid()) {

src/Operation/Collapse.php

@@ -18,7 +18,8 @@ final class Collapse extends Operation
     public function run(CollectionInterface $collection): CollectionInterface
     {
         return Collection::with(
-            static function () use ($collection) {
+            static function () use ($collection): \Generator
+            {
                 foreach ($collection as $item) {
                     if (\is_array($item) || $item instanceof CollectionInterface) {
                         foreach ($item as $value) {

src/Operation/Combine.php

@@ -20,7 +20,8 @@ public function run(CollectionInterface $collection): CollectionInterface
         [$keys] = $this->parameters;
 
         return Collection::with(
-            static function () use ($keys, $collection) {
+            static function () use ($keys, $collection): \Generator
+            {
                 $original = $collection->getIterator();
                 $keysIterator = Collection::with($keys)->getIterator();
 

src/Operation/Count.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace drupol\collection\Operation;
+
+use drupol\collection\Contract\Collection as CollectionInterface;
+
+/**
+ * Class Count.
+ *
+ * Be careful, this will only work with finite collection sets.
+ */
+final class Count extends Operation
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function run(CollectionInterface $collection)
+    {
+        return \iterator_count($collection->getIterator());
+    }
+}

src/Operation/Filter.php

@@ -17,19 +17,22 @@ final class Filter extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $callback = $this->parameters[0];
+        [$callbacks] = $this->parameters;
 
-        if (null === $callback) {
-            $callback = static function ($value) {
+        if ([] === $callbacks) {
+            $callbacks[] = static function ($value) {
                 return $value;
             };
         }
 
         return Collection::with(
-            static function () use ($callback, $collection) {
-                foreach ($collection->getIterator() as $key => $value) {
-                    if (true === (bool) $callback($value, $key)) {
-                        yield $key => $value;
+            static function () use ($callbacks, $collection): \Generator
+            {
+                foreach ($callbacks as $callback) {
+                    foreach ($collection->getIterator() as $key => $value) {
+                        if (true === (bool) $callback($value, $key)) {
+                            yield $key => $value;
+                        }
                     }
                 }
             }

src/Operation/Flatten.php

@@ -20,7 +20,8 @@ public function run(CollectionInterface $collection): CollectionInterface
         $depth = $this->parameters[0];
 
         return Collection::with(
-            static function () use ($depth, $collection) {
+            static function () use ($depth, $collection): \Generator
+            {
                 $iterator = $collection->getIterator();
 
                 foreach ($iterator as $item) {

src/Operation/Flip.php

@@ -18,7 +18,8 @@ final class Flip extends Operation
     public function run(CollectionInterface $collection): CollectionInterface
     {
         return Collection::with(
-            static function () use ($collection) {
+            static function () use ($collection): \Generator
+            {
                 foreach ($collection as $key => $value) {
                     yield $value => $key;
                 }

src/Operation/Forget.php

@@ -20,7 +20,8 @@ public function run(CollectionInterface $collection): CollectionInterface
         [$keys] = $this->parameters;
 
         return Collection::with(
-            static function () use ($keys, $collection) {
+            static function () use ($keys, $collection): \Generator
+            {
                 $keys = \array_flip($keys);
 
                 foreach ($collection->getIterator() as $key => $value) {

src/Operation/Keys.php

@@ -18,7 +18,8 @@ final class Keys extends Operation
     public function run(CollectionInterface $collection): CollectionInterface
     {
         return Collection::with(
-            static function () use ($collection) {
+            static function () use ($collection): \Generator
+            {
                 foreach ($collection as $key => $value) {
                     yield $key;
                 }

src/Operation/Last.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace drupol\collection\Operation;
+
+use drupol\collection\Contract\Collection as CollectionInterface;
+
+/**
+ * Class Last.
+ *
+ * Be careful, this will only work with finite collection sets.
+ */
+final class Last extends Operation
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function run(CollectionInterface $collection)
+    {
+        /** @var \Iterator $iterator */
+        $iterator = $collection->getIterator();
+
+        $iterator->rewind();
+
+        $last = $iterator->current();
+
+        while (true === $iterator->valid()) {
+            $last = $iterator->current();
+            $iterator->next();
+        }
+
+        return $last;
+    }
+}