src/Illuminate/Collections/Traits/EnumeratesValues.php
<?php
namespace Illuminate\Support\Traits;
use BackedEnum;
use CachingIterator;
use Closure;
use Exception;
use Illuminate\Contracts\Support\Arrayable;
use Illuminate\Contracts\Support\Jsonable;
use Illuminate\Support\Arr;
use Illuminate\Support\Collection;
use Illuminate\Support\Enumerable;
use Illuminate\Support\HigherOrderCollectionProxy;
use InvalidArgumentException;
use JsonSerializable;
use Traversable;
use UnexpectedValueException;
use UnitEnum;
use WeakMap;
/**
* @template TKey of array-key
*
* @template-covariant TValue
*
* @property-read HigherOrderCollectionProxy $average
* @property-read HigherOrderCollectionProxy $avg
* @property-read HigherOrderCollectionProxy $contains
* @property-read HigherOrderCollectionProxy $doesntContain
* @property-read HigherOrderCollectionProxy $each
* @property-read HigherOrderCollectionProxy $every
* @property-read HigherOrderCollectionProxy $filter
* @property-read HigherOrderCollectionProxy $first
* @property-read HigherOrderCollectionProxy $flatMap
* @property-read HigherOrderCollectionProxy $groupBy
* @property-read HigherOrderCollectionProxy $keyBy
* @property-read HigherOrderCollectionProxy $map
* @property-read HigherOrderCollectionProxy $max
* @property-read HigherOrderCollectionProxy $min
* @property-read HigherOrderCollectionProxy $partition
* @property-read HigherOrderCollectionProxy $percentage
* @property-read HigherOrderCollectionProxy $reject
* @property-read HigherOrderCollectionProxy $skipUntil
* @property-read HigherOrderCollectionProxy $skipWhile
* @property-read HigherOrderCollectionProxy $some
* @property-read HigherOrderCollectionProxy $sortBy
* @property-read HigherOrderCollectionProxy $sortByDesc
* @property-read HigherOrderCollectionProxy $sum
* @property-read HigherOrderCollectionProxy $takeUntil
* @property-read HigherOrderCollectionProxy $takeWhile
* @property-read HigherOrderCollectionProxy $unique
* @property-read HigherOrderCollectionProxy $unless
* @property-read HigherOrderCollectionProxy $until
* @property-read HigherOrderCollectionProxy $when
*/
trait EnumeratesValues
{
use Conditionable;
/**
* Indicates that the object's string representation should be escaped when __toString is invoked.
*
* @var bool
*/
protected $escapeWhenCastingToString = false;
/**
* The methods that can be proxied.
*
* @var array<int, string>
*/
protected static $proxies = [
'average',
'avg',
'contains',
'doesntContain',
'each',
'every',
'filter',
'first',
'flatMap',
'groupBy',
'keyBy',
'map',
'max',
'min',
'partition',
'percentage',
'reject',
'skipUntil',
'skipWhile',
'some',
'sortBy',
'sortByDesc',
'sum',
'takeUntil',
'takeWhile',
'unique',
'unless',
'until',
'when',
];
/**
* Create a new collection instance if the value isn't one already.
*
* @template TMakeKey of array-key
* @template TMakeValue
*
* @param \Illuminate\Contracts\Support\Arrayable<TMakeKey, TMakeValue>|iterable<TMakeKey, TMakeValue>|null $items
* @return static<TMakeKey, TMakeValue>
*/
public static function make($items = [])
{
return new static($items);
}
/**
* Wrap the given value in a collection if applicable.
*
* @template TWrapValue
*
* @param iterable<array-key, TWrapValue>|TWrapValue $value
* @return static<array-key, TWrapValue>
*/
public static function wrap($value)
{
return $value instanceof Enumerable
? new static($value)
: new static(Arr::wrap($value));
}
/**
* Get the underlying items from the given collection if applicable.
*
* @template TUnwrapKey of array-key
* @template TUnwrapValue
*
* @param array<TUnwrapKey, TUnwrapValue>|static<TUnwrapKey, TUnwrapValue> $value
* @return array<TUnwrapKey, TUnwrapValue>
*/
public static function unwrap($value)
{
return $value instanceof Enumerable ? $value->all() : $value;
}
/**
* Create a new instance with no items.
*
* @return static
*/
public static function empty()
{
return new static([]);
}
/**
* Create a new collection by invoking the callback a given amount of times.
*
* @template TTimesValue
*
* @param int $number
* @param (callable(int): TTimesValue)|null $callback
* @return static<int, TTimesValue>
*/
public static function times($number, ?callable $callback = null)
{
if ($number < 1) {
return new static;
}
return static::range(1, $number)
->unless($callback == null)
->map($callback);
}
/**
* Alias for the "avg" method.
*
* @param (callable(TValue): float|int)|string|null $callback
* @return float|int|null
*/
public function average($callback = null)
{
return $this->avg($callback);
}
/**
* Alias for the "contains" method.
*
* @param (callable(TValue, TKey): bool)|TValue|string $key
* @param mixed $operator
* @param mixed $value
* @return bool
*/
public function some($key, $operator = null, $value = null)
{
return $this->contains(...func_get_args());
}
/**
* Dump the given arguments and terminate execution.
*
* @param mixed ...$args
* @return never
*/
public function dd(...$args)
{
$this->dump(...$args);
dd();
}
/**
* Dump the items.
*
* @param mixed ...$args
* @return $this
*/
public function dump(...$args)
{
dump($this->all(), ...$args);
return $this;
}
/**
* Execute a callback over each item.
*
* @param callable(TValue, TKey): mixed $callback
* @return $this
*/
public function each(callable $callback)
{
foreach ($this as $key => $item) {
if ($callback($item, $key) === false) {
break;
}
}
return $this;
}
/**
* Execute a callback over each nested chunk of items.
*
* @param callable(...mixed): mixed $callback
* @return static
*/
public function eachSpread(callable $callback)
{
return $this->each(function ($chunk, $key) use ($callback) {
$chunk[] = $key;
return $callback(...$chunk);
});
}
/**
* Determine if all items pass the given truth test.
*
* @param (callable(TValue, TKey): bool)|TValue|string $key
* @param mixed $operator
* @param mixed $value
* @return bool
*/
public function every($key, $operator = null, $value = null)
{
if (func_num_args() === 1) {
$callback = $this->valueRetriever($key);
foreach ($this as $k => $v) {
if (! $callback($v, $k)) {
return false;
}
}
return true;
}
return $this->every($this->operatorForWhere(...func_get_args()));
}
/**
* Get the first item by the given key value pair.
*
* @param callable|string $key
* @param mixed $operator
* @param mixed $value
* @return TValue|null
*/
public function firstWhere($key, $operator = null, $value = null)
{
return $this->first($this->operatorForWhere(...func_get_args()));
}
/**
* Get a single key's value from the first matching item in the collection.
*
* @template TValueDefault
*
* @param string $key
* @param TValueDefault|(\Closure(): TValueDefault) $default
* @return TValue|TValueDefault
*/
public function value($key, $default = null)
{
if ($value = $this->firstWhere($key)) {
return data_get($value, $key, $default);
}
return value($default);
}
/**
* Ensure that every item in the collection is of the expected type.
*
* @template TEnsureOfType
*
* @param class-string<TEnsureOfType>|array<array-key, class-string<TEnsureOfType>> $type
* @return static<TKey, TEnsureOfType>
*
* @throws \UnexpectedValueException
*/
public function ensure($type)
{
$allowedTypes = is_array($type) ? $type : [$type];
return $this->each(function ($item, $index) use ($allowedTypes) {
$itemType = get_debug_type($item);
foreach ($allowedTypes as $allowedType) {
if ($itemType === $allowedType || $item instanceof $allowedType) {
return true;
}
}
throw new UnexpectedValueException(
sprintf("Collection should only include [%s] items, but '%s' found at position %d.", implode(', ', $allowedTypes), $itemType, $index)
);
});
}
/**
* Determine if the collection is not empty.
*
* @return bool
*/
public function isNotEmpty()
{
return ! $this->isEmpty();
}
/**
* Run a map over each nested chunk of items.
*
* @template TMapSpreadValue
*
* @param callable(mixed...): TMapSpreadValue $callback
* @return static<TKey, TMapSpreadValue>
*/
public function mapSpread(callable $callback)
{
return $this->map(function ($chunk, $key) use ($callback) {
$chunk[] = $key;
return $callback(...$chunk);
});
}
/**
* Run a grouping map over the items.
*
* The callback should return an associative array with a single key/value pair.
*
* @template TMapToGroupsKey of array-key
* @template TMapToGroupsValue
*
* @param callable(TValue, TKey): array<TMapToGroupsKey, TMapToGroupsValue> $callback
* @return static<TMapToGroupsKey, static<int, TMapToGroupsValue>>
*/
public function mapToGroups(callable $callback)
{
$groups = $this->mapToDictionary($callback);
return $groups->map([$this, 'make']);
}
/**
* Map a collection and flatten the result by a single level.
*
* @template TFlatMapKey of array-key
* @template TFlatMapValue
*
* @param callable(TValue, TKey): (\Illuminate\Support\Collection<TFlatMapKey, TFlatMapValue>|array<TFlatMapKey, TFlatMapValue>) $callback
* @return static<TFlatMapKey, TFlatMapValue>
*/
public function flatMap(callable $callback)
{
return $this->map($callback)->collapse();
}
/**
* Map the values into a new class.
*
* @template TMapIntoValue
*
* @param class-string<TMapIntoValue> $class
* @return static<TKey, TMapIntoValue>
*/
public function mapInto($class)
{
if (is_subclass_of($class, BackedEnum::class)) {
return $this->map(fn ($value, $key) => $class::from($value));
}
return $this->map(fn ($value, $key) => new $class($value, $key));
}
/**
* Get the min value of a given key.
*
* @param (callable(TValue):mixed)|string|null $callback
* @return mixed
*/
public function min($callback = null)
{
$callback = $this->valueRetriever($callback);
return $this->map(fn ($value) => $callback($value))
->filter(fn ($value) => ! is_null($value))
->reduce(fn ($result, $value) => is_null($result) || $value < $result ? $value : $result);
}
/**
* Get the max value of a given key.
*
* @param (callable(TValue):mixed)|string|null $callback
* @return mixed
*/
public function max($callback = null)
{
$callback = $this->valueRetriever($callback);
return $this->filter(fn ($value) => ! is_null($value))->reduce(function ($result, $item) use ($callback) {
$value = $callback($item);
return is_null($result) || $value > $result ? $value : $result;
});
}
/**
* "Paginate" the collection by slicing it into a smaller collection.
*
* @param int $page
* @param int $perPage
* @return static
*/
public function forPage($page, $perPage)
{
$offset = max(0, ($page - 1) * $perPage);
return $this->slice($offset, $perPage);
}
/**
* Partition the collection into two arrays using the given callback or key.
*
* @param (callable(TValue, TKey): bool)|TValue|string $key
* @param TValue|string|null $operator
* @param TValue|null $value
* @return static<int<0, 1>, static<TKey, TValue>>
*/
public function partition($key, $operator = null, $value = null)
{
$passed = [];
$failed = [];
$callback = func_num_args() === 1
? $this->valueRetriever($key)
: $this->operatorForWhere(...func_get_args());
foreach ($this as $key => $item) {
if ($callback($item, $key)) {
$passed[$key] = $item;
} else {
$failed[$key] = $item;
}
}
return new static([new static($passed), new static($failed)]);
}
/**
* Calculate the percentage of items that pass a given truth test.
*
* @param (callable(TValue, TKey): bool) $callback
* @param int $precision
* @return float|null
*/
public function percentage(callable $callback, int $precision = 2)
{
if ($this->isEmpty()) {
return null;
}
return round(
$this->filter($callback)->count() / $this->count() * 100,
$precision
);
}
/**
* Get the sum of the given values.
*
* @param (callable(TValue): mixed)|string|null $callback
* @return mixed
*/
public function sum($callback = null)
{
$callback = is_null($callback)
? $this->identity()
: $this->valueRetriever($callback);
return $this->reduce(fn ($result, $item) => $result + $callback($item), 0);
}
/**
* Apply the callback if the collection is empty.
*
* @template TWhenEmptyReturnType
*
* @param (callable($this): TWhenEmptyReturnType) $callback
* @param (callable($this): TWhenEmptyReturnType)|null $default
* @return $this|TWhenEmptyReturnType
*/
public function whenEmpty(callable $callback, ?callable $default = null)
{
return $this->when($this->isEmpty(), $callback, $default);
}
/**
* Apply the callback if the collection is not empty.
*
* @template TWhenNotEmptyReturnType
*
* @param callable($this): TWhenNotEmptyReturnType $callback
* @param (callable($this): TWhenNotEmptyReturnType)|null $default
* @return $this|TWhenNotEmptyReturnType
*/
public function whenNotEmpty(callable $callback, ?callable $default = null)
{
return $this->when($this->isNotEmpty(), $callback, $default);
}
/**
* Apply the callback unless the collection is empty.
*
* @template TUnlessEmptyReturnType
*
* @param callable($this): TUnlessEmptyReturnType $callback
* @param (callable($this): TUnlessEmptyReturnType)|null $default
* @return $this|TUnlessEmptyReturnType
*/
public function unlessEmpty(callable $callback, ?callable $default = null)
{
return $this->whenNotEmpty($callback, $default);
}
/**
* Apply the callback unless the collection is not empty.
*
* @template TUnlessNotEmptyReturnType
*
* @param callable($this): TUnlessNotEmptyReturnType $callback
* @param (callable($this): TUnlessNotEmptyReturnType)|null $default
* @return $this|TUnlessNotEmptyReturnType
*/
public function unlessNotEmpty(callable $callback, ?callable $default = null)
{
return $this->whenEmpty($callback, $default);
}
/**
* Filter items by the given key value pair.
*
* @param callable|string $key
* @param mixed $operator
* @param mixed $value
* @return static
*/
public function where($key, $operator = null, $value = null)
{
return $this->filter($this->operatorForWhere(...func_get_args()));
}
/**
* Filter items where the value for the given key is null.
*
* @param string|null $key
* @return static
*/
public function whereNull($key = null)
{
return $this->whereStrict($key, null);
}
/**
* Filter items where the value for the given key is not null.
*
* @param string|null $key
* @return static
*/
public function whereNotNull($key = null)
{
return $this->where($key, '!==', null);
}
/**
* Filter items by the given key value pair using strict comparison.
*
* @param string $key
* @param mixed $value
* @return static
*/
public function whereStrict($key, $value)
{
return $this->where($key, '===', $value);
}
/**
* Filter items by the given key value pair.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @param bool $strict
* @return static
*/
public function whereIn($key, $values, $strict = false)
{
$values = $this->getArrayableItems($values);
return $this->filter(fn ($item) => in_array(data_get($item, $key), $values, $strict));
}
/**
* Filter items by the given key value pair using strict comparison.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @return static
*/
public function whereInStrict($key, $values)
{
return $this->whereIn($key, $values, true);
}
/**
* Filter items such that the value of the given key is between the given values.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @return static
*/
public function whereBetween($key, $values)
{
return $this->where($key, '>=', reset($values))->where($key, '<=', end($values));
}
/**
* Filter items such that the value of the given key is not between the given values.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @return static
*/
public function whereNotBetween($key, $values)
{
return $this->filter(
fn ($item) => data_get($item, $key) < reset($values) || data_get($item, $key) > end($values)
);
}
/**
* Filter items by the given key value pair.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @param bool $strict
* @return static
*/
public function whereNotIn($key, $values, $strict = false)
{
$values = $this->getArrayableItems($values);
return $this->reject(fn ($item) => in_array(data_get($item, $key), $values, $strict));
}
/**
* Filter items by the given key value pair using strict comparison.
*
* @param string $key
* @param \Illuminate\Contracts\Support\Arrayable|iterable $values
* @return static
*/
public function whereNotInStrict($key, $values)
{
return $this->whereNotIn($key, $values, true);
}
/**
* Filter the items, removing any items that don't match the given type(s).
*
* @template TWhereInstanceOf
*
* @param class-string<TWhereInstanceOf>|array<array-key, class-string<TWhereInstanceOf>> $type
* @return static<TKey, TWhereInstanceOf>
*/
public function whereInstanceOf($type)
{
return $this->filter(function ($value) use ($type) {
if (is_array($type)) {
foreach ($type as $classType) {
if ($value instanceof $classType) {
return true;
}
}
return false;
}
return $value instanceof $type;
});
}
/**
* Pass the collection to the given callback and return the result.
*
* @template TPipeReturnType
*
* @param callable($this): TPipeReturnType $callback
* @return TPipeReturnType
*/
public function pipe(callable $callback)
{
return $callback($this);
}
/**
* Pass the collection into a new class.
*
* @template TPipeIntoValue
*
* @param class-string<TPipeIntoValue> $class
* @return TPipeIntoValue
*/
public function pipeInto($class)
{
return new $class($this);
}
/**
* Pass the collection through a series of callable pipes and return the result.
*
* @param array<callable> $callbacks
* @return mixed
*/
public function pipeThrough($callbacks)
{
return Collection::make($callbacks)->reduce(
fn ($carry, $callback) => $callback($carry),
$this,
);
}
/**
* Reduce the collection to a single value.
*
* @template TReduceInitial
* @template TReduceReturnType
*
* @param callable(TReduceInitial|TReduceReturnType, TValue, TKey): TReduceReturnType $callback
* @param TReduceInitial $initial
* @return TReduceReturnType
*/
public function reduce(callable $callback, $initial = null)
{
$result = $initial;
foreach ($this as $key => $value) {
$result = $callback($result, $value, $key);
}
return $result;
}
/**
* Reduce the collection to multiple aggregate values.
*
* @param callable $callback
* @param mixed ...$initial
* @return array
*
* @throws \UnexpectedValueException
*/
public function reduceSpread(callable $callback, ...$initial)
{
$result = $initial;
foreach ($this as $key => $value) {
$result = call_user_func_array($callback, array_merge($result, [$value, $key]));
if (! is_array($result)) {
throw new UnexpectedValueException(sprintf(
"%s::reduceSpread expects reducer to return an array, but got a '%s' instead.",
class_basename(static::class), gettype($result)
));
}
}
return $result;
}
/**
* Reduce an associative collection to a single value.
*
* @template TReduceWithKeysInitial
* @template TReduceWithKeysReturnType
*
* @param callable(TReduceWithKeysInitial|TReduceWithKeysReturnType, TValue, TKey): TReduceWithKeysReturnType $callback
* @param TReduceWithKeysInitial $initial
* @return TReduceWithKeysReturnType
*/
public function reduceWithKeys(callable $callback, $initial = null)
{
return $this->reduce($callback, $initial);
}
/**
* Create a collection of all elements that do not pass a given truth test.
*
* @param (callable(TValue, TKey): bool)|bool|TValue $callback
* @return static
*/
public function reject($callback = true)
{
$useAsCallable = $this->useAsCallable($callback);
return $this->filter(function ($value, $key) use ($callback, $useAsCallable) {
return $useAsCallable
? ! $callback($value, $key)
: $value != $callback;
});
}
/**
* Pass the collection to the given callback and then return it.
*
* @param callable($this): mixed $callback
* @return $this
*/
public function tap(callable $callback)
{
$callback($this);
return $this;
}
/**
* Return only unique items from the collection array.
*
* @param (callable(TValue, TKey): mixed)|string|null $key
* @param bool $strict
* @return static
*/
public function unique($key = null, $strict = false)
{
$callback = $this->valueRetriever($key);
$exists = [];
return $this->reject(function ($item, $key) use ($callback, $strict, &$exists) {
if (in_array($id = $callback($item, $key), $exists, $strict)) {
return true;
}
$exists[] = $id;
});
}
/**
* Return only unique items from the collection array using strict comparison.
*
* @param (callable(TValue, TKey): mixed)|string|null $key
* @return static
*/
public function uniqueStrict($key = null)
{
return $this->unique($key, true);
}
/**
* Collect the values into a collection.
*
* @return \Illuminate\Support\Collection<TKey, TValue>
*/
public function collect()
{
return new Collection($this->all());
}
/**
* Get the collection of items as a plain array.
*
* @return array<TKey, mixed>
*/
public function toArray()
{
return $this->map(fn ($value) => $value instanceof Arrayable ? $value->toArray() : $value)->all();
}
/**
* Convert the object into something JSON serializable.
*
* @return array<TKey, mixed>
*/
public function jsonSerialize(): array
{
return array_map(function ($value) {
if ($value instanceof JsonSerializable) {
return $value->jsonSerialize();
} elseif ($value instanceof Jsonable) {
return json_decode($value->toJson(), true);
} elseif ($value instanceof Arrayable) {
return $value->toArray();
}
return $value;
}, $this->all());
}
/**
* Get the collection of items as JSON.
*
* @param int $options
* @return string
*/
public function toJson($options = 0)
{
return json_encode($this->jsonSerialize(), $options);
}
/**
* Get a CachingIterator instance.
*
* @param int $flags
* @return \CachingIterator
*/
public function getCachingIterator($flags = CachingIterator::CALL_TOSTRING)
{
return new CachingIterator($this->getIterator(), $flags);
}
/**
* Convert the collection to its string representation.
*
* @return string
*/
public function __toString()
{
return $this->escapeWhenCastingToString
? e($this->toJson())
: $this->toJson();
}
/**
* Indicate that the model's string representation should be escaped when __toString is invoked.
*
* @param bool $escape
* @return $this
*/
public function escapeWhenCastingToString($escape = true)
{
$this->escapeWhenCastingToString = $escape;
return $this;
}
/**
* Add a method to the list of proxied methods.
*
* @param string $method
* @return void
*/
public static function proxy($method)
{
static::$proxies[] = $method;
}
/**
* Dynamically access collection proxies.
*
* @param string $key
* @return mixed
*
* @throws \Exception
*/
public function __get($key)
{
if (! in_array($key, static::$proxies)) {
throw new Exception("Property [{$key}] does not exist on this collection instance.");
}
return new HigherOrderCollectionProxy($this, $key);
}
/**
* Results array of items from Collection or Arrayable.
*
* @param mixed $items
* @return array<TKey, TValue>
*/
protected function getArrayableItems($items)
{
if (is_array($items)) {
return $items;
}
return match (true) {
$items instanceof WeakMap => throw new InvalidArgumentException('Collections can not be created using instances of WeakMap.'),
$items instanceof Enumerable => $items->all(),
$items instanceof Arrayable => $items->toArray(),
$items instanceof Traversable => iterator_to_array($items),
$items instanceof Jsonable => json_decode($items->toJson(), true),
$items instanceof JsonSerializable => (array) $items->jsonSerialize(),
$items instanceof UnitEnum => [$items],
default => (array) $items,
};
}
/**
* Get an operator checker callback.
*
* @param callable|string $key
* @param string|null $operator
* @param mixed $value
* @return \Closure
*/
protected function operatorForWhere($key, $operator = null, $value = null)
{
if ($this->useAsCallable($key)) {
return $key;
}
if (func_num_args() === 1) {
$value = true;
$operator = '=';
}
if (func_num_args() === 2) {
$value = $operator;
$operator = '=';
}
return function ($item) use ($key, $operator, $value) {
$retrieved = data_get($item, $key);
$strings = array_filter([$retrieved, $value], function ($value) {
return is_string($value) || (is_object($value) && method_exists($value, '__toString'));
});
if (count($strings) < 2 && count(array_filter([$retrieved, $value], 'is_object')) == 1) {
return in_array($operator, ['!=', '<>', '!==']);
}
switch ($operator) {
default:
case '=':
case '==': return $retrieved == $value;
case '!=':
case '<>': return $retrieved != $value;
case '<': return $retrieved < $value;
case '>': return $retrieved > $value;
case '<=': return $retrieved <= $value;
case '>=': return $retrieved >= $value;
case '===': return $retrieved === $value;
case '!==': return $retrieved !== $value;
case '<=>': return $retrieved <=> $value;
}
};
}
/**
* Determine if the given value is callable, but not a string.
*
* @param mixed $value
* @return bool
*/
protected function useAsCallable($value)
{
return ! is_string($value) && is_callable($value);
}
/**
* Get a value retrieving callback.
*
* @param callable|string|null $value
* @return callable
*/
protected function valueRetriever($value)
{
if ($this->useAsCallable($value)) {
return $value;
}
return fn ($item) => data_get($item, $value);
}
/**
* Make a function to check an item's equality.
*
* @param mixed $value
* @return \Closure(mixed): bool
*/
protected function equality($value)
{
return fn ($item) => $item === $value;
}
/**
* Make a function using another function, by negating its result.
*
* @param \Closure $callback
* @return \Closure
*/
protected function negate(Closure $callback)
{
return fn (...$params) => ! $callback(...$params);
}
/**
* Make a function that returns what's passed to it.
*
* @return \Closure(TValue): TValue
*/
protected function identity()
{
return fn ($value) => $value;
}
}