Require Closures in more places instead of callable

Non-closure callables have strange context-dependent behaviour and are slower to call than a closure. It's possible to use Closure::fromCallable() in the origin scope, which guarantees that the callable will remain callable no matter where it's used.

src/pocketmine/network/mcpe/CompressBatchPromise.php

@@ -27,7 +27,7 @@ use pocketmine\utils\Utils;
 use function array_push;
 
 class CompressBatchPromise{
-	/** @var callable[] */
+	/** @var \Closure[] */
 	private $callbacks = [];
 
 	/** @var string|null */
@@ -36,7 +36,7 @@ class CompressBatchPromise{
 	/** @var bool */
 	private $cancelled = false;
 
-	public function onResolve(callable ...$callbacks) : void{
+	public function onResolve(\Closure ...$callbacks) : void{
 		$this->checkCancelled();
 		foreach($callbacks as $callback){
 			Utils::validateCallableSignature(function(CompressBatchPromise $promise){}, $callback);
@@ -64,7 +64,7 @@ class CompressBatchPromise{
 	}
 
 	/**
-	 * @return callable[]
+	 * @return \Closure[]
 	 */
 	public function getResolveCallbacks() : array{
 		return $this->callbacks;

src/pocketmine/utils/Internet.php

@@ -187,13 +187,13 @@ class Internet{
 	 * @param float|int     $timeout The maximum connect timeout and timeout in seconds, correct to ms.
 	 * @param string[]      $extraHeaders extra headers to send as a plain string array
 	 * @param array         $extraOpts extra CURLOPT_* to set as an [opt => value] map
-	 * @param callable|null $onSuccess    function to be called if there is no error. Accepts a resource argument as the cURL handle.
+	 * @param \Closure|null $onSuccess function to be called if there is no error. Accepts a resource argument as the cURL handle.
 	 *
 	 * @return array a plain array of three [result body : string, headers : array[], HTTP response code : int]. Headers are grouped by requests with strtolower(header name) as keys and header value as values
 	 *
 	 * @throws InternetException if a cURL error occurs
 	 */
-	public static function simpleCurl(string $page, $timeout = 10, array $extraHeaders = [], array $extraOpts = [], ?callable $onSuccess = null) : array{
+	public static function simpleCurl(string $page, $timeout = 10, array $extraHeaders = [], array $extraOpts = [], ?\Closure $onSuccess = null) : array{
 		if(!self::$online){
 			throw new InternetException("Cannot execute web request while offline");
 		}

src/pocketmine/world/BlockTransaction.php

@@ -134,9 +134,9 @@ class BlockTransaction{
 	 * The callable signature should be the same as the below dummy function.
 	 * @see BlockTransaction::dummyValidator()
 	 *
-	 * @param callable $validator
+	 * @param \Closure $validator
 	 */
-	public function addValidator(callable $validator) : void{
+	public function addValidator(\Closure $validator) : void{
 		Utils::validateCallableSignature([$this, 'dummyValidator'], $validator);
 		$this->validators[] = $validator;
 	}