refactor: Minor documentation changes.

spec/loophp/collection/CollectionSpec.php

@@ -1970,6 +1970,10 @@ static function ($carry, $item) {
 
     public function it_can_reverse(): void
     {
+        $this::empty()
+            ->reverse()
+            ->shouldIterateAs([]);
+
         $this::fromIterable(range('A', 'F'))
             ->reverse()
             ->shouldIterateAs([5 => 'F', 4 => 'E', 3 => 'D', 2 => 'C', 1 => 'B', 0 => 'A']);
@@ -2473,7 +2477,6 @@ public function it_can_unpack(): void
             ['c', 'c'],
             ['d', 'd'],
             ['e', 'e'],
-            'bar',
         ];
 
         $this::fromIterable($input)
@@ -2490,7 +2493,6 @@ public function it_can_unpack(): void
             ['a', 'b', 'c' => 'c', 'd' => 'd'],
             ['e', 'f', 'g' => 'g', 'h' => 'h'],
             ['i', 'j'],
-            'foo',
         ];
 
         $this::fromIterable($input)

src/Operation/Pack.php

@@ -22,11 +22,11 @@ public function __invoke(): Closure
     {
         $mapCallback =
             /**
+             * @param mixed $value
              * @psalm-param T $value
-             * @psalm-param TKey $key
              *
-             * @param mixed $value
              * @param mixed $key
+             * @psalm-param TKey $key
              *
              * @psalm-return array{0: TKey, 1: T}
              */

src/Operation/Reverse.php

@@ -9,6 +9,10 @@
 use Iterator;
 
 /**
+ * @todo Remove the Wrap and Unwrap operations
+ * @todo They are only needed when: Collection::empty()->reverse()
+ * @todo Most probably that the FoldLeft operation needs an update.
+ *
  * @psalm-template TKey
  * @psalm-template TKey of array-key
  * @psalm-template T
@@ -37,9 +41,9 @@ public function __invoke(): Closure
         $pipe = Pipe::of()(
             Pack::of(),
             Wrap::of(),
-            FoldLeft1::of()($callback),
+            FoldLeft::of()($callback)([]),
             Unwrap::of(),
-            Unpack::of()
+            Unpack::of(),
         );
 
         // Point free style.

src/Operation/Unpack.php

@@ -23,40 +23,30 @@ final class Unpack extends AbstractOperation
      */
     public function __invoke(): Closure
     {
-        $isIterable =
-            /**
-             * @param mixed $value
-             * @psalm-param T $value
-             */
-            static fn ($value): bool => is_iterable($value);
-
         $toIterableIterator = static fn (iterable $value): Iterator => new IterableIterator($value);
 
         $callbackForKeys =
             /**
+             * @param mixed $initial
              * @psalm-param T $initial
              * @psalm-param array{0: TKey, 1: T} $value
              *
              * @psalm-return TKey
-             *
-             * @param mixed $initial
              */
             static fn ($initial, int $key, array $value) => $value[0];
 
         $callbackForValues =
             /**
+             * @param mixed $initial
              * @psalm-param T $initial
              * @psalm-param array{0: TKey, 1: T} $value
              *
              * @psalm-return T
-             *
-             * @param mixed $initial
              */
             static fn ($initial, int $key, array $value) => $value[1];
 
         /** @psalm-var Closure(Iterator<int, array{0: TKey, 1: T}>): Generator<T, T> $pipe */
         $pipe = Pipe::of()(
-            Filter::of()($isIterable),
             Map::of()($toIterableIterator, Chunk::of()(2)),
             Unwrap::of(),
             Associate::of()($callbackForKeys)($callbackForValues)