Add access with offset and first/last methods

+ Simplify/Correct template declarations
+ Fix method signatures (self → static)

composer.json

@@ -2,20 +2,10 @@
     "name":              "jrosset/collections",
     "description":       "Classes for collections",
     "keywords":          [ ],
-    "type":              "library",
-
-    "config":            {
-        "sort-packages": true
-    },
-    "extra":             {
-        "branch-alias": {
-            "dev-master": "3.x-dev"
-        }
-    },
 
     "minimum-stability": "stable",
     "require":           {
-        "php": "^8.1"
+        "php": "^7.4 || ^8.0"
     },
     "autoload":          {
         "psr-4":                 {
@@ -40,4 +30,4 @@
         "docs":   "https://git.jrosset.ovh/jrosset/PhpCollections/wiki",
         "source": "https://git.jrosset.ovh/jrosset/PhpCollections"
     }
-}
+}

src/Collections/Collection.php

@@ -17,40 +17,40 @@ class Collection extends ImmutableCollection implements ICollection {
     /**
      * @inheritDoc
      */
-    public function set ($key, $value): static {
+    public function set ($key, $value) {
         return $this->_set($key, $value);
     }
     /**
      * @inheritDoc
      */
-    public function merge (IImmutableCollection ...$collections): static {
+    public function merge (IImmutableCollection ...$collections) {
         return $this->_merge(...$collections);
     }
 
     /**
      * @inheritDoc
      */
-    public function add (...$values): static {
+    public function add (...$values) {
         return $this->_add(...$values);
     }
     /**
      * @inheritDoc
      */
-    public function addCollection (IImmutableCollection ...$collections): static {
+    public function addCollection (IImmutableCollection ...$collections) {
         return $this->_addCollection(...$collections);
     }
 
     /**
      * @inheritDoc
      */
-    public function prepend (...$values): static {
+    public function prepend (...$values) {
         array_unshift($this->elements, ...$values);
         return $this;
     }
     /**
      * @inheritDoc
      */
-    public function prependCollection (IImmutableCollection ...$collections): static {
+    public function prependCollection (IImmutableCollection ...$collections) {
         $prepend = array_merge(
             ...array_map(
                    function (IImmutableCollection $collection): array {
@@ -65,21 +65,21 @@ class Collection extends ImmutableCollection implements ICollection {
     /**
      * @inheritDoc
      */
-    public function clear (): static {
+    public function clear () {
         $this->_initialize();
         return $this;
     }
     /**
      * @inheritDoc
      */
-    public function remove ($key): static {
+    public function remove ($key) {
         unset($this->elements[$this->_normalizeKey($key)]);
         return $this;
     }
     /**
      * @inheritDoc
      */
-    public function removeValue ($value, bool $strict = false): static {
+    public function removeValue ($value, bool $strict = false) {
         foreach ($this->elements as $currentKey => $currentValue) {
             if (($strict && $value === $currentValue) || (!$strict && $value == $currentValue)) {
                 unset($this->elements[$currentKey]);
@@ -112,41 +112,37 @@ class Collection extends ImmutableCollection implements ICollection {
     /**
      * @inheritDoc
      */
-    public function offsetSet (mixed $offset, mixed $value): void {
+    public function offsetSet ($offset, $value): void {
         $this->set($offset, $value);
     }
     /**
      * @inheritDoc
      */
-    public function offsetUnset (mixed $offset): void {
+    public function offsetUnset ($offset): void {
         $this->remove($offset);
     }
 
     /**
      * @inheritDoc
      */
-    public function sliceSelf (int $offset, ?int $length = null): static {
-        if ($this->count() === 0) {
-            $this->elements = [];
-        }
-        else {
-            $this->_checkOffset($offset);
-            $this->elements = array_slice($this->elements, $offset, $length, true);
-        }
+    public function sliceSelf (int $offset, ?int $length = null) {
+        $this->_checkOffset($offset);
+
+        $this->elements = array_slice($this->elements, $offset, $length, true);
         return $this;
     }
 
     /**
      * @inheritDoc
      */
-    public function filterSelf (Closure $filter): static {
+    public function filterSelf (Closure $filter) {
         $this->elements = array_filter($this->elements, $filter);
         return $this;
     }
     /**
      * @inheritDoc
      */
-    public function removeEmpties (): static {
+    public function removeEmpties () {
         return $this->filterSelf(function ($value) {
             return empty($value);
         });
@@ -154,22 +150,22 @@ class Collection extends ImmutableCollection implements ICollection {
     /**
      * @inheritDoc
      */
-    public function mapSelf (Closure $process): static {
-        $this->elements = $this->map($process)->elements;
+    public function mapSelf (Closure $process) {
+        $this->elements = array_map($process, $this->elements);
         return $this;
     }
 
     /**
      * @inheritDoc
      */
-    public function sortSelf (Closure|IComparator|null $sorter = null): static {
+    public function sortSelf ($sorter = null) {
         uasort($this->elements, self::_normalizeSorter($sorter));
         return $this;
     }
     /**
      * @inheritDoc
      */
-    public function sortSelfByKey (Closure|IComparator $sorter): static {
+    public function sortSelfByKey ($sorter) {
         uksort($this->elements, self::_normalizeSorter($sorter));
         return $this;
     }

src/Collections/ICollection.php

@@ -3,8 +3,8 @@
 namespace jrosset\Collections;
 
 use Closure;
+use Exception;
 use OutOfBoundsException;
-use Throwable;
 
 /**
  * Interface for a collection
@@ -22,16 +22,20 @@ interface ICollection extends IImmutableCollection {
      * @param TValue $value The value
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function set ($key, $value): static;
+    public function set ($key, $value);
     /**
      * Merge one or multiple collections into the current one
      *
      * @param IImmutableCollection<TKey, TValue> ...$collections The collections to merge
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function merge (IImmutableCollection ...$collections): static;
+    public function merge (IImmutableCollection ...$collections);
 
     /**
      * Add one or multiple values
@@ -39,16 +43,20 @@ interface ICollection extends IImmutableCollection {
      * @param TValue ...$values The values
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function add (...$values): static;
+    public function add (...$values);
     /**
      * Add the <b>values</b> of one or multiple collections
      *
      * @param IImmutableCollection<TKey, TValue> ...$collections The collections to add
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function addCollection (IImmutableCollection ...$collections): static;
+    public function addCollection (IImmutableCollection ...$collections);
 
     /**
      * Add one or multiple values at the beginning of the current collection
@@ -56,31 +64,39 @@ interface ICollection extends IImmutableCollection {
      * @param TValue ...$values The values
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function prepend (...$values): static;
+    public function prepend (...$values);
     /**
      * Add the <b>values</b> of one or multiple collections at the beginning of the current collection
      *
      * @param IImmutableCollection<TKey, TValue> ...$collections The collections to add
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function prependCollection (IImmutableCollection ...$collections): static;
+    public function prependCollection (IImmutableCollection ...$collections);
 
     /**
      * Empty the collection
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function clear (): static;
+    public function clear ();
     /**
      * Remove a value from it's key
      *
      * @param TKey $key The key
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function remove ($key): static;
+    public function remove ($key);
     /**
      * Delete all instances of a value
      *
@@ -88,8 +104,10 @@ interface ICollection extends IImmutableCollection {
      * @param bool   $strict Strict comparison ?
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function removeValue ($value, bool $strict = false): static;
+    public function removeValue ($value, bool $strict = false);
 
     /**
      * Get and remove the first element
@@ -119,8 +137,10 @@ interface ICollection extends IImmutableCollection {
      * @return $this
      *
      * @throws OutOfBoundsException If the offset is not valid
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function sliceSelf (int $offset, ?int $length = null): static;
+    public function sliceSelf (int $offset, ?int $length = null);
 
     /**
      * Keep only elements that satisfy predicate $filter
@@ -128,24 +148,30 @@ interface ICollection extends IImmutableCollection {
      * @param Closure(TKey, TValue):bool $filter The filtering predicate
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function filterSelf (Closure $filter): static;
+    public function filterSelf (Closure $filter);
     /**
      * Keep only non-empty elements
      *
      * Use {@see https://www.php.net/manual/function.empty.php empty} to check if element is empty or not
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function removeEmpties (): static;
+    public function removeEmpties ();
     /**
      * Applied <b>$process</b> on all elements
      *
      * @param Closure(TKey, TValue): TValue $process The process function to apply on each element
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function mapSelf (Closure $process): static;
+    public function mapSelf (Closure $process);
 
     /**
      * Sort the elements (by value)
@@ -158,9 +184,11 @@ interface ICollection extends IImmutableCollection {
      *
      * @return $this
      *
-     * @throws Throwable If an error occurs
+     * @throws Exception If an error occurs
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function sortSelf (Closure|IComparator|null $sorter = null): static;
+    public function sortSelf ($sorter = null);
     /**
      * Sort the elements by key
      *
@@ -171,7 +199,9 @@ interface ICollection extends IImmutableCollection {
      *
      * @return $this
      *
-     * @throws Throwable If an error occurs
+     * @throws Exception If an error occurs
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function sortSelfByKey (Closure|IComparator $sorter): static;
+    public function sortSelfByKey ($sorter);
 }

src/Collections/IImmutableCollection.php

@@ -8,6 +8,7 @@ use Countable;
 use IteratorAggregate;
 use JsonSerializable;
 use OutOfBoundsException;
+use Serializable;
 use Throwable;
 
 /**
@@ -20,7 +21,7 @@ use Throwable;
  * @implements ArrayAccess<TKey, TValue>
  * @implements IArrayCast<TKey, TValue>
  */
-interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Countable, ArrayAccess, IArrayCast {
+interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Serializable, Countable, ArrayAccess, IArrayCast {
     /**
      * Checks if the collection is empty
      *
@@ -130,8 +131,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @return static<TKey, TValue> The result collection
      *
      * @throws OutOfBoundsException If the offset is not valid
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function slice (int $offset, ?int $length = null): static;
+    public function slice (int $offset, ?int $length = null);
 
     /**
      * Get a collection of all elements that satisfy predicate $filter
@@ -139,16 +142,20 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param Closure(TKey, TValue):bool $filter The filtering predicate
      *
      * @return static<TKey, TValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function filter (Closure $filter): static;
+    public function filter (Closure $filter);
     /**
      * Get a collection of all not empty elements
      *
      * Use {@see https://www.php.net/manual/function.empty.php empty} to check if element is empty or not
      *
      * @return static<TKey, TValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function withoutEmpties (): static;
+    public function withoutEmpties ();
     /**
      * A new collection with <b>$process</b> applied on all elements
      *
@@ -157,8 +164,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param Closure(TKey, TValue): TResultValue $process The process function to apply on each element
      *
      * @return static<TKey, TResultValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function map (Closure $process): static;
+    public function map (Closure $process);
 
     /**
      * Get a collection with the elements sorted (by value)
@@ -172,8 +181,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @return static<TKey, TValue> The result collection
      *
      * @throws Throwable If an error occurs
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function sort (Closure|IComparator|null $sorter = null): static;
+    public function sort ($sorter = null);
     /**
      * Get a collection with the elements sorted by key
      *
@@ -185,8 +196,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @return static<TKey, TValue> The result collection
      *
      * @throws Throwable If an error occurs
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function sortByKey (Closure|IComparator $sorter): static;
+    public function sortByKey ($sorter);
 
     /**
      * The list of all keys
@@ -198,8 +211,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * The list of all values
      *
      * @return static<int, TValue> The list of all values
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function values (): static;
+    public function values ();
 
     /**
      * Join all values with a separator
@@ -216,8 +231,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param string $separator The split separator
      *
      * @return static<int, string> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public static function split (string $value, string $separator): static;
+    public static function split (string $value, string $separator);
 
     /**
      * Create a collection filled with the same element
@@ -226,8 +243,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param TValue $value The value to fill the collection
      *
      * @return static<int, TValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public static function fill (int $size, $value): static;
+    public static function fill (int $size, $value);
     /**
      * Create a collection filled with the same element, using a list of keys
      *
@@ -235,8 +254,10 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param TValue                     $value The value to fill the collection
      *
      * @return static<TKey, TValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public static function fillWithKeys (IImmutableCollection $keys, $value): static;
+    public static function fillWithKeys (IImmutableCollection $keys, $value);
 
     /**
      * Merge the current collection with one or multiple collections
@@ -244,6 +265,8 @@ interface IImmutableCollection extends IteratorAggregate, JsonSerializable, Coun
      * @param IImmutableCollection<TKey, TValue> ...$collections The other collections to merge
      *
      * @return static<TKey, TValue> The result collection
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    public function mergeWith (IImmutableCollection ...$collections): static;
+    public function mergeWith (IImmutableCollection ...$collections);
 }

src/Collections/ImmutableCollection.php

@@ -6,7 +6,6 @@ use ArrayIterator;
 use Closure;
 use InvalidArgumentException;
 use OutOfBoundsException;
-use ReflectionFunction;
 use Traversable;
 
 /**
@@ -64,8 +63,10 @@ class ImmutableCollection implements IImmutableCollection {
      * @return $this
      *
      * @internal
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    protected function _set ($key, $value): static {
+    protected function _set ($key, $value) {
         $this->elements[$this->_normalizeKey($key)] = $value;
         return $this;
     }
@@ -77,8 +78,10 @@ class ImmutableCollection implements IImmutableCollection {
      * @return $this
      *
      * @internal
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    protected function _merge (IImmutableCollection ...$collections): static {
+    protected function _merge (IImmutableCollection ...$collections) {
         foreach ($collections as $collection) {
             foreach ($collection as $key => $value) {
                 $this->_set($key, $value);
@@ -94,8 +97,10 @@ class ImmutableCollection implements IImmutableCollection {
      * @return $this
      *
      * @internal
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    protected function _add (...$values): static {
+    protected function _add (...$values) {
         foreach ($values as $value) {
             $this->elements[] = $value;
         }
@@ -107,8 +112,10 @@ class ImmutableCollection implements IImmutableCollection {
      * @param IImmutableCollection ...$collections The collections to add
      *
      * @return $this
+     *
+     * @noinspection PhpMissingReturnTypeInspection
      */
-    protected function _addCollection (IImmutableCollection ...$collections): static {
+    protected function _addCollection (IImmutableCollection ...$collections) {
         foreach ($collections as $collection) {
             foreach ($collection as $value) {
                 $this->_add($value);
@@ -151,25 +158,25 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function offsetExists (mixed $offset): bool {
+    public function offsetExists ($offset): bool {
         return $this->exists($offset);
     }
     /**
      * @inheritDoc
      */
-    public function offsetGet (mixed $offset): mixed {
+    public function offsetGet ($offset) {
         return $this->get($offset);
     }
     /**
      * @inheritDoc
      */
-    public function offsetSet (mixed $offset, mixed $value): void {
+    public function offsetSet ($offset, $value): void {
         throw new ImmutableException();
     }
     /**
      * @inheritDoc
      */
-    public function offsetUnset (mixed $offset): void {
+    public function offsetUnset ($offset): void {
         throw new ImmutableException();
     }
 
@@ -184,14 +191,16 @@ class ImmutableCollection implements IImmutableCollection {
         ];
     }
     /**
-     * {@see https://www.php.net/manual/function.unserialize.php Unserialize} from the list of serialized properties
-     *
-     * @param array $data The list of serialized properties
-     *
-     * @return void
+     * @inheritDoc
+     */
+    public function serialize (): ?string {
+        return serialize($this->elements);
+    }
+    /**
+     * @inheritDoc
      */
-    public function __unserialize (array $data): void {
-        $this->_initialize($data['elements']);
+    public function unserialize ($data) {
+        $this->_initialize(unserialize($data));
     }
 
     /**
@@ -230,7 +239,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function get ($key): mixed {
+    public function get ($key) {
         return $this->elements[$this->_normalizeKey($key)] ?? null;
     }
     /**
@@ -289,14 +298,11 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function slice (int $offset, ?int $length = null): static {
-        $output = new static();
-        if ($this->count() === 0) {
-            return $output;
-        }
-
+    public function slice (int $offset, ?int $length = null) {
         $this->_checkOffset($offset);
 
+        $output = new static();
+
         $currentIndex = 0;
         foreach ($this->elements as $key => $value) {
             if ($currentIndex++ < $offset) {
@@ -315,7 +321,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function filter (Closure $filter): static {
+    public function filter (Closure $filter) {
         $output = new static();
         foreach ($this->elements as $key => $value) {
             if (!$filter($key, $value)) {
@@ -328,7 +334,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function withoutEmpties (): static {
+    public function withoutEmpties () {
         return $this->filter(function ($value) {
             return empty($value);
         });
@@ -336,21 +342,10 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function map (Closure $process): static {
-        //region Regarde si $process doit être appelée avec la clé en plus de la valeur
-        $callProcessWithKey = false;
-        /** @noinspection PhpUnhandledExceptionInspection */
-        $processReflection = new ReflectionFunction($process);
-        if (count($processReflection->getParameters()) >= 2) {
-            if (!$processReflection->getParameters()[1]->isDefaultValueAvailable()) {
-                $callProcessWithKey = true;
-            }
-        }
-        //endregion
-
+    public function map (Closure $process) {
         $output = new static();
         foreach ($this->elements as $key => $value) {
-            $output->_set($key, $callProcessWithKey ? $process($key, $value) : $process($value));
+            $output->_set($key, $process($key, $value));
         }
         return $output;
     }
@@ -358,7 +353,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function sort (Closure|IComparator|null $sorter = null): static {
+    public function sort ($sorter = null) {
         $elements = $this->toArray();
         uasort($elements, self::_normalizeSorter($sorter));
 
@@ -367,7 +362,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function sortByKey (Closure|IComparator $sorter): static {
+    public function sortByKey ($sorter) {
         $elements = $this->toArray();
         uksort($elements, self::_normalizeSorter($sorter));
 
@@ -389,7 +384,7 @@ class ImmutableCollection implements IImmutableCollection {
      *                                     <br>= 0 if value1 equals value2
      *                                     <br>&gt; 0 if value1 is after value2
      */
-    public static function _normalizeSorter (Closure|IComparator|null $sorter): Closure {
+    public static function _normalizeSorter ($sorter): Closure {
         if ($sorter === null) {
             return function (IComparable $value1, IComparable $value2): int {
                 return $value1->compareTo($value2);
@@ -414,14 +409,14 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function values (): static {
+    public function values () {
         return new static(array_values($this->elements));
     }
 
     /**
      * @inheritDoc
      */
-    public function jsonSerialize (): mixed {
+    public function jsonSerialize () {
         return $this->elements;
     }
 
@@ -434,14 +429,14 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public static function split (string $value, string $separator): static {
+    public static function split (string $value, string $separator) {
         return new static (explode($separator, $value));
     }
 
     /**
      * @inheritDoc
      */
-    public static function fill (int $size, $value): static {
+    public static function fill (int $size, $value) {
         $keys = new ImmutableCollection();
         for ($curr = 0; $curr < $size; $curr++) {
             $keys->_add($curr);
@@ -452,7 +447,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public static function fillWithKeys (IImmutableCollection $keys, $value): static {
+    public static function fillWithKeys (IImmutableCollection $keys, $value) {
         $collection = new static();
         foreach ($keys as $key) {
             $collection->_set($key, $value);
@@ -463,7 +458,7 @@ class ImmutableCollection implements IImmutableCollection {
     /**
      * @inheritDoc
      */
-    public function mergeWith (IImmutableCollection ...$collections): static {
+    public function mergeWith (IImmutableCollection ...$collections) {
         return (clone $this)->_merge(...$collections);
     }
 }

src/Collections/TInsensitiveCaseKey.php

@@ -7,9 +7,11 @@ namespace jrosset\Collections;
  */
 trait TInsensitiveCaseKey {
     /**
-     * @inheritDoc
+     * Normalize a key
      *
-     * @noinspection PhpMissingReturnTypeInspection
+     * @param array-key $key The key to normalize
+     *
+     * @return array-key The normalized key
      */
     protected function _normalizeKey ($key) {
         return mb_strtolower($key);

src/Collections/TUniqueValues.php

@@ -12,7 +12,7 @@ trait TUniqueValues {
     /**
      * @inheritDoc
      */
-    protected function _set ($key, $value): static {
+    protected function _set ($key, $value): self {
         if ($this->contains($value)) {
             return $this;
         }
@@ -23,7 +23,7 @@ trait TUniqueValues {
     /**
      * @inheritDoc
      */
-    protected function _add (...$values): static {
+    protected function _add (...$values): self {
         foreach ($values as $value) {
             if ($this->contains($value)) {
                 continue;