Minor code updates and increase code coverage.

spec/drupol/collection/CollectionSpec.php

@@ -38,7 +38,23 @@ public function it_can_apply(): void
 
         $this
             ->apply(static function ($item) {
-                return (bool) ($item % 2);
+                // do what you want here.
+
+                return true;
+            })
+            ->shouldIterateAs(\range(1, 10));
+
+        $this
+            ->apply(static function ($item) {
+                // do what you want here.
+
+                return false;
+            })
+            ->shouldIterateAs(\range(1, 10));
+
+        $this
+            ->apply(static function ($item): void {
+                $item %= 2;
             })
             ->shouldIterateAs([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
 
@@ -108,6 +124,24 @@ public function it_can_apply(): void
             })
             ->all()
             ->shouldReturn($context);
+
+        $context = [];
+
+        $applyCallback1 = static function ($item, $key) use (&$context) {
+            $context[] = $item;
+
+            return true;
+        };
+
+        $walkCallback2 = static function ($item) {
+            return $item;
+        };
+
+        $this::with(\range(1, 20))
+            ->apply($applyCallback1)
+            ->walk($walkCallback2)
+            ->all()
+            ->shouldReturn($context);
     }
 
     public function it_can_be_constructed_from_array(): void

src/Collection.php

@@ -63,15 +63,15 @@ public function all(): array
      */
     public function append(...$items): CollectionInterface
     {
-        return $this->run(Append::with(...$items));
+        return $this->run(Append::with($items));
     }
 
     /**
      * {@inheritdoc}
      */
-    public function apply(callable $callback): CollectionInterface
+    public function apply(callable ...$callables): CollectionInterface
     {
-        return $this->run(Apply::with($callback));
+        return $this->run(Apply::with($callables));
     }
 
     /**
@@ -95,7 +95,7 @@ public function collapse(): CollectionInterface
      */
     public function combine($keys): CollectionInterface
     {
-        return $this->run(Combine::with(...$keys));
+        return $this->run(Combine::with($keys));
     }
 
     /**
@@ -159,7 +159,7 @@ public function flip(): CollectionInterface
      */
     public function forget(...$keys): CollectionInterface
     {
-        return $this->run(Forget::with(...$keys));
+        return $this->run(Forget::with($keys));
     }
 
     /**
@@ -199,15 +199,15 @@ public function limit(int $limit): CollectionInterface
      */
     public function map(callable ...$callbacks): CollectionInterface
     {
-        return $this->run(Walk::with(...$callbacks), Normalize::with());
+        return $this->run(Walk::with($callbacks), Normalize::with());
     }
 
     /**
      * {@inheritdoc}
      */
     public function merge(...$sources): CollectionInterface
     {
-        return $this->run(Merge::with(...\array_map([$this, 'makeIterator'], $sources)));
+        return $this->run(Merge::with(\array_map([$this, 'makeIterator'], $sources)));
     }
 
     /**
@@ -231,7 +231,7 @@ public function nth(int $step, int $offset = 0): CollectionInterface
      */
     public function only(...$keys): CollectionInterface
     {
-        return $this->run(Only::with(...$keys));
+        return $this->run(Only::with($keys));
     }
 
     /**
@@ -255,7 +255,7 @@ public function pluck($pluck, $default = null): CollectionInterface
      */
     public function prepend(...$items): CollectionInterface
     {
-        return $this->run(Prepend::with(...$items));
+        return $this->run(Prepend::with($items));
     }
 
     /**
@@ -309,7 +309,7 @@ public function run(Operation ...$operations)
      */
     public function skip(int ...$counts): CollectionInterface
     {
-        return $this->run(Skip::with(...$counts));
+        return $this->run(Skip::with($counts));
     }
 
     /**
@@ -350,13 +350,13 @@ static function () use ($number) {
      */
     public function walk(callable ...$callbacks): CollectionInterface
     {
-        return $this->run(Walk::with(...$callbacks));
+        return $this->run(Walk::with($callbacks));
     }
 
     /**
      * Create a new collection instance.
      *
-     * @param null|array|callable|Closure|CollectionInterface $data
+     * @param null|array|callable|Closure|CollectionInterface|\Iterator $data
      *
      * @return \drupol\collection\Contract\Collection
      */
@@ -374,7 +374,7 @@ public static function with($data = []): CollectionInterface
      */
     public function zip(...$items): CollectionInterface
     {
-        return $this->run(Zip::with(...$items));
+        return $this->run(Zip::with($items));
     }
 
     /**

src/Contract/Collection.php

@@ -31,11 +31,11 @@ public function append(...$items): self;
     /**
      * Apply a callback to all the element of an array.
      *
-     * @param callable $callable
+     * @param callable ...$callables
      *
      * @return \drupol\collection\Contract\Collection
      */
-    public function apply(callable $callable): self;
+    public function apply(callable ...$callables): self;
 
     /**
      * Chunk the collection into chunks of the given size.

src/Operation/Append.php

@@ -17,7 +17,7 @@ final class Append extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $items = $this->parameters;
+        [$items] = $this->parameters;
 
         return Collection::with(
             static function () use ($items, $collection) {

src/Operation/Apply.php

@@ -17,13 +17,13 @@ final class Apply extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        [$callback] = $this->parameters;
+        [$callbacks] = $this->parameters;
 
-        $newCollection = Collection::with($collection);
-
-        foreach ($newCollection as $key => $item) {
-            if (false === $callback($item, $key)) {
-                break;
+        foreach ($callbacks as $callback) {
+            foreach (Collection::with($collection) as $key => $item) {
+                if (false === $callback($item, $key)) {
+                    break;
+                }
             }
         }
 

src/Operation/Combine.php

@@ -17,7 +17,7 @@ final class Combine extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $keys = $this->parameters;
+        [$keys] = $this->parameters;
 
         return Collection::with(
             static function () use ($keys, $collection) {

src/Operation/Forget.php

@@ -17,7 +17,7 @@ final class Forget extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $keys = $this->parameters;
+        [$keys] = $this->parameters;
 
         return Collection::with(
             static function () use ($keys, $collection) {

src/Operation/Merge.php

@@ -17,7 +17,7 @@ final class Merge extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $sources = $this->parameters;
+        [$sources] = $this->parameters;
 
         return Collection::with(
             static function () use ($sources, $collection) {

src/Operation/Only.php

@@ -17,7 +17,7 @@ final class Only extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $keys = $this->parameters;
+        [$keys] = $this->parameters;
 
         return Collection::with(
             static function () use ($keys, $collection) {

src/Operation/Prepend.php

@@ -17,7 +17,7 @@ final class Prepend extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $items = $this->parameters;
+        [$items] = $this->parameters;
 
         return Collection::with(
             static function () use ($items, $collection) {

src/Operation/Rebase.php

@@ -17,6 +17,6 @@ final class Rebase extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        return Collection::with($collection->all());
+        return Collection::with($collection->getIterator());
     }
 }

src/Operation/Skip.php

@@ -17,7 +17,7 @@ final class Skip extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $counts = $this->parameters;
+        [$counts] = $this->parameters;
 
         return Collection::with(
             static function () use ($counts, $collection) {

src/Operation/Walk.php

@@ -17,7 +17,7 @@ final class Walk extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $callbacks = $this->parameters;
+        [$callbacks] = $this->parameters;
 
         return Collection::with(
             static function () use ($callbacks, $collection) {

src/Operation/Zip.php

@@ -17,7 +17,7 @@ final class Zip extends Operation
      */
     public function run(CollectionInterface $collection): CollectionInterface
     {
-        $iterables = $this->parameters;
+        [$iterables] = $this->parameters;
 
         return Collection::with(
             static function () use ($iterables, $collection) {