Add readonly where appropriate

src/ConcurrentArrayIterator.php

@@ -8,17 +8,17 @@
 final class ConcurrentArrayIterator implements ConcurrentIterator
 {
     private int $position = 0;
-    private int $size;
+    private readonly int $size;
 
-    private array $values;
+    private readonly array $values;
 
-    private FiberLocal $currentPosition;
+    private readonly FiberLocal $currentPosition;
 
     private ?DisposedException $disposed = null;
 
     public function __construct(array $values)
     {
-        $this->values = \PHP_VERSION_ID >= 80100 && \array_is_list($values) ? $values : \array_values($values);
+        $this->values = \array_is_list($values) ? $values : \array_values($values);
         $this->size = \count($values);
         $this->currentPosition = new FiberLocal(fn () => throw new \Error('Call continue() before calling get()'));
     }

src/ConcurrentChainedIterator.php

@@ -16,10 +16,10 @@
 final class ConcurrentChainedIterator implements ConcurrentIterator
 {
     /** @var ConcurrentIterator<T>[] */
-    private array $iterators;
+    private readonly array $iterators;
 
     /** @var FiberLocal<int|null> */
-    private FiberLocal $position;
+    private readonly FiberLocal $position;
 
     /**
      * @param ConcurrentIterator<T>[] $iterators

src/ConcurrentIterableIterator.php

@@ -14,7 +14,7 @@
 final class ConcurrentIterableIterator implements ConcurrentIterator
 {
     /** @var ConcurrentIterator<T> */
-    private ConcurrentIterator $iterator;
+    private readonly ConcurrentIterator $iterator;
 
     /**
      * @param iterable<array-key, T> $iterable

src/Internal/ConcurrentClosureIterator.php

@@ -15,15 +15,15 @@
  */
 final class ConcurrentClosureIterator implements ConcurrentIterator
 {
-    private \Closure $supplier;
+    private readonly \Closure $supplier;
 
-    private \SplQueue $sources;
+    private readonly \SplQueue $sources;
 
-    private QueueState $queue;
+    private readonly QueueState $queue;
 
-    private Sequence $sequence;
+    private readonly Sequence $sequence;
 
-    private DeferredCancellation $deferredCancellation;
+    private readonly DeferredCancellation $deferredCancellation;
 
     private int $cancellations = 0;
 

src/Internal/ConcurrentFlatMapIterator.php

@@ -16,7 +16,7 @@
 final class ConcurrentFlatMapIterator implements ConcurrentIterator
 {
     /** @var ConcurrentIterator<T> */
-    private ConcurrentIterator $iterator;
+    private readonly ConcurrentIterator $iterator;
 
     /**
      * @template R

src/Internal/ConcurrentQueueIterator.php

@@ -8,7 +8,7 @@
 /** @internal */
 final class ConcurrentQueueIterator implements ConcurrentIterator
 {
-    private QueueState $state;
+    private readonly QueueState $state;
 
     public function __construct(QueueState $state)
     {

src/Internal/FlatMapOperation.php

@@ -20,12 +20,12 @@ public static function getStopMarker(): object
         return $marker ??= new \stdClass;
     }
 
-    private int $concurrency;
+    private readonly int $concurrency;
 
-    private bool $ordered;
+    private readonly bool $ordered;
 
     /** @var \Closure(T, int):iterable<R> */
-    private \Closure $flatMap;
+    private readonly \Closure $flatMap;
 
     /**
      * @param \Closure(T, int):iterable<R> $flatMap

src/Internal/QueueState.php

@@ -50,10 +50,10 @@ final class QueueState implements \IteratorAggregate
     private int $positionOffset = 0;
 
     /** @var FiberLocal<int|null> */
-    private FiberLocal $currentPosition;
+    private readonly FiberLocal $currentPosition;
 
     /** @var FiberLocal<T|null> */
-    private FiberLocal $currentValue;
+    private readonly FiberLocal $currentValue;
 
     public function __construct(int $bufferSize = 0)
     {

src/Internal/SortOperation.php

@@ -8,7 +8,7 @@
 /** @internal */
 final class SortOperation implements IntermediateOperation
 {
-    private \Closure $compare;
+    private readonly \Closure $compare;
 
     public function __construct(\Closure $compare)
     {

src/Pipeline.php

@@ -93,7 +93,7 @@ public static function concat(array $pipelines): self
         ));
     }
 
-    private ConcurrentIterator $source;
+    private readonly ConcurrentIterator $source;
 
     private int $concurrency = 1;
 

src/Queue.php

@@ -17,7 +17,7 @@
 final class Queue
 {
     /** @var Internal\QueueState<T> Has public emit, complete, and fail methods. */
-    private Internal\QueueState $state;
+    private readonly Internal\QueueState $state;
 
     /**
      * @param int $bufferSize Allowed number of items to internally buffer before awaiting backpressure from the