Add types to iterable_map()

Author: simPod

src/iterable-functions.php

@@ -16,14 +16,19 @@
 /**
  * Maps a callable to an iterable.
  *
- * @param iterable<mixed> $iterable
+ * @param iterable<TKey, TValue> $iterable
+ * @param callable(TValue):TResult $mapper
+ *
+ * @return iterable<TKey, TValue2>
  *
- * @return iterable<mixed>
+ * @template TKey
+ * @template TValue
+ * @template TResult
  */
-function iterable_map(iterable $iterable, callable $map): iterable
+function iterable_map(iterable $iterable, callable $mapper): iterable
 {
     foreach ($iterable as $key => $item) {
-        yield $key => $map($item);
+        yield $key => $mapper($item);
     }
 }