diff --git a/docs/pages/api.rst b/docs/pages/api.rst
index 3d701bb73..c89aa2dbc 100644
--- a/docs/pages/api.rst
+++ b/docs/pages/api.rst
@@ -463,6 +463,25 @@ Signature: ``Collection::distinct();``
$collection = Collection::with(['a', 'b', 'c', 'd', 'a'])
->distinct()
+dropWhile
+~~~~~~~~~
+
+It inspects the original collection and takes from it its elements from the moment when the condition fails for the
+first time till the end of the list.
+
+Interface: `DropWhileable`_
+
+Signature: ``Collection::dropWhile(callable $callback);``
+
+.. code-block:: php
+
+ $isSmallerThanThree = static function (int $value): bool {
+ return 3 > $value;
+ };
+
+ Collection::fromIterable([1,2,3,4,5,6,7,8,9,1,2,3])
+ ->dropWhile($isSmallerThanThree); // [3,4,5,6,7,8,9,1,2,3]
+
explode
~~~~~~~
@@ -1558,6 +1577,7 @@ Signature: ``Collection::zip(iterable ...$iterables);``
.. _Diffable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Diffable.php
.. _Diffkeysable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Diffkeysable.php
.. _Distinctable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Distinctable.php
+.. _DropWhileable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/DropWhileable.php
.. _Explodeable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Explodeable.php
.. _Falsyable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Falsyable.php
.. _Filterable: https://github.com/loophp/collection/blob/master/src/Contract/Operation/Filterable.php
diff --git a/spec/loophp/collection/CollectionSpec.php b/spec/loophp/collection/CollectionSpec.php
index b5663dff3..d9b784c04 100644
--- a/spec/loophp/collection/CollectionSpec.php
+++ b/spec/loophp/collection/CollectionSpec.php
@@ -543,6 +543,28 @@ public function it_can_do_the_cartesian_product(): void
->shouldIterateAs([0 => ['A', 1], 1 => ['A', 2], 2 => ['B', 1], 3 => ['B', 2], 4 => ['C', 1], 5 => ['C', 2]]);
}
+ public function it_can_dropWhile(): void
+ {
+ $isSmallerThanThree = static function ($value) {
+ return 3 > $value;
+ };
+
+ $this::fromIterable([1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3])
+ ->dropWhile($isSmallerThanThree)
+ ->shouldIterateAs([
+ 2 => 3,
+ 3 => 4,
+ 4 => 5,
+ 5 => 6,
+ 6 => 7,
+ 7 => 8,
+ 8 => 9,
+ 9 => 1,
+ 10 => 2,
+ 11 => 3,
+ ]);
+ }
+
public function it_can_explode(): void
{
$string = 'I am just a random piece of text.';
diff --git a/src/Collection.php b/src/Collection.php
index 253a293fc..b461e33a5 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -29,6 +29,7 @@
use loophp\collection\Operation\Diff;
use loophp\collection\Operation\DiffKeys;
use loophp\collection\Operation\Distinct;
+use loophp\collection\Operation\DropWhile;
use loophp\collection\Operation\Explode;
use loophp\collection\Operation\Falsy;
use loophp\collection\Operation\Filter;
@@ -324,6 +325,11 @@ public function distinct(): CollectionInterface
return $this->run(Distinct::of());
}
+ public function dropWhile(callable $callback): CollectionInterface
+ {
+ return $this->run(DropWhile::of()($callback));
+ }
+
public static function empty(): Collection
{
return new self();
diff --git a/src/Contract/Collection.php b/src/Contract/Collection.php
index 5023c5d0a..3df5bfca2 100644
--- a/src/Contract/Collection.php
+++ b/src/Contract/Collection.php
@@ -23,6 +23,7 @@
use loophp\collection\Contract\Operation\Diffable;
use loophp\collection\Contract\Operation\Diffkeysable;
use loophp\collection\Contract\Operation\Distinctable;
+use loophp\collection\Contract\Operation\DropWhileable;
use loophp\collection\Contract\Operation\Explodeable;
use loophp\collection\Contract\Operation\Falsyable;
use loophp\collection\Contract\Operation\Filterable;
@@ -109,6 +110,7 @@
* @template-extends Diffable<TKey, T>
* @template-extends Diffkeysable<TKey, T>
* @template-extends Distinctable<TKey, T>
+ * @template-extends DropWhileable<TKey, T>
* @template-extends Explodeable<TKey, T>
* @template-extends Filterable<TKey, T>
* @template-extends Firstable<TKey, T>
@@ -185,6 +187,7 @@ interface Collection extends
Diffable,
Diffkeysable,
Distinctable,
+ DropWhileable,
Explodeable,
Falsyable,
Filterable,
diff --git a/src/Contract/Operation/DropWhileable.php b/src/Contract/Operation/DropWhileable.php
new file mode 100644
index 000000000..78abd0a37
--- /dev/null
+++ b/src/Contract/Operation/DropWhileable.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace loophp\collection\Contract\Operation;
+
+use loophp\collection\Contract\Collection;
+
+/**
+ * @psalm-template TKey
+ * @psalm-template TKey of array-key
+ * @psalm-template T
+ */
+interface DropWhileable
+{
+ /**
+ * @psalm-return \loophp\collection\Contract\Collection<TKey, T>
+ */
+ public function dropWhile(callable $callback): Collection;
+}
diff --git a/src/Operation/DropWhile.php b/src/Operation/DropWhile.php
new file mode 100644
index 000000000..0d29a42c4
--- /dev/null
+++ b/src/Operation/DropWhile.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace loophp\collection\Operation;
+
+use Closure;
+use Generator;
+use Iterator;
+
+/**
+ * @psalm-template TKey
+ * @psalm-template TKey of array-key
+ * @psalm-template T
+ *
+ * phpcs:disable Generic.Files.LineLength.TooLong
+ */
+final class DropWhile extends AbstractOperation
+{
+ /**
+ * @psalm-return Closure((callable(T, TKey, Iterator<TKey, T>): bool)): Closure(Iterator<TKey, T>): Generator<TKey, T>
+ */
+ public function __invoke(): Closure
+ {
+ return
+ /**
+ * @psalm-param callable(T, TKey, Iterator<TKey, T>):bool $callback
+ *
+ * @psalm-return Closure(Iterator<TKey, T>): Generator<TKey, T>
+ */
+ static function (callable $callback): Closure {
+ return
+ /**
+ * @psalm-param Iterator<TKey, T> $iterator
+ *
+ * @psalm-return Generator<TKey, T>
+ */
+ static function (Iterator $iterator) use ($callback): Generator {
+ for (; $iterator->valid(); $iterator->next()) {
+ if (true === $callback($iterator->current(), $iterator->key(), $iterator)) {
+ continue;
+ }
+
+ break;
+ }
+
+ for (; $iterator->valid(); $iterator->next()) {
+ yield $iterator->key() => $iterator->current();
+ }
+ };
+ };
+ }
+}