diff --git a/demo/parsing-whole-directory/example1.php b/demo/parsing-whole-directory/example1.php
index ab9f687ba..96cce7613 100644
--- a/demo/parsing-whole-directory/example1.php
+++ b/demo/parsing-whole-directory/example1.php
@@ -17,6 +17,11 @@
 
 $reflector = new DefaultReflector($sourceLocator);
 
-$classReflections = $reflector->reflectAllClasses();
+$generator = $reflector->reflectAllClasses();
+
+$classReflections = [];
+foreach ($generator as $classReflection) {
+    $classReflections[] = $classReflection;
+}
 
 !empty($classReflections) && print 'success';
diff --git a/demo/parsing-whole-directory/example2.php b/demo/parsing-whole-directory/example2.php
index b7e514816..db4a45adc 100644
--- a/demo/parsing-whole-directory/example2.php
+++ b/demo/parsing-whole-directory/example2.php
@@ -23,6 +23,11 @@
 
 $reflector = new DefaultReflector($sourceLocator);
 
-$classReflections = $reflector->reflectAllClasses();
+$generator = $reflector->reflectAllClasses();
+
+$classReflections = [];
+foreach ($generator as $classReflection) {
+    $classReflections[] = $classReflection;
+}
 
 !empty($classReflections) && print 'success';
diff --git a/src/Reflector/DefaultReflector.php b/src/Reflector/DefaultReflector.php
index 8fb250047..8db4b2c55 100644
--- a/src/Reflector/DefaultReflector.php
+++ b/src/Reflector/DefaultReflector.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\Reflector;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\ReflectionClass;
@@ -43,11 +44,11 @@ public function reflectClass(string $identifierName): ReflectionClass
     /**
      * Get all the classes available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionClass>
+     * @return Generator<ReflectionClass>
      */
-    public function reflectAllClasses(): iterable
+    public function reflectAllClasses(): Generator
     {
-        /** @var list<ReflectionClass> $allClasses */
+        /** @var Generator<ReflectionClass> $allClasses */
         $allClasses = $this->sourceLocator->locateIdentifiersByType(
             $this,
             new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
@@ -79,11 +80,11 @@ public function reflectFunction(string $identifierName): ReflectionFunction
     /**
      * Get all the functions available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionFunction>
+     * @return Generator<ReflectionFunction>
      */
-    public function reflectAllFunctions(): iterable
+    public function reflectAllFunctions(): Generator
     {
-        /** @var list<ReflectionFunction> $allFunctions */
+        /** @var Generator<ReflectionFunction> $allFunctions */
         $allFunctions = $this->sourceLocator->locateIdentifiersByType(
             $this,
             new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION),
@@ -115,11 +116,11 @@ public function reflectConstant(string $identifierName): ReflectionConstant
     /**
      * Get all the constants available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionConstant>
+     * @return Generator<ReflectionConstant>
      */
-    public function reflectAllConstants(): iterable
+    public function reflectAllConstants(): Generator
     {
-        /** @var list<ReflectionConstant> $allConstants */
+        /** @var Generator<ReflectionConstant> $allConstants */
         $allConstants = $this->sourceLocator->locateIdentifiersByType(
             $this,
             new IdentifierType(IdentifierType::IDENTIFIER_CONSTANT),
diff --git a/src/Reflector/Reflector.php b/src/Reflector/Reflector.php
index d9d9b1e44..df4fe4461 100644
--- a/src/Reflector/Reflector.php
+++ b/src/Reflector/Reflector.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\Reflector;
 
+use Generator;
 use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionConstant;
 use Roave\BetterReflection\Reflection\ReflectionFunction;
@@ -21,9 +22,9 @@ public function reflectClass(string $identifierName): ReflectionClass;
     /**
      * Get all the classes available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionClass>
+     * @return Generator<ReflectionClass>
      */
-    public function reflectAllClasses(): iterable;
+    public function reflectAllClasses(): Generator;
 
     /**
      * Create a ReflectionFunction for the specified $functionName.
@@ -35,9 +36,9 @@ public function reflectFunction(string $identifierName): ReflectionFunction;
     /**
      * Get all the functions available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionFunction>
+     * @return Generator<ReflectionFunction>
      */
-    public function reflectAllFunctions(): iterable;
+    public function reflectAllFunctions(): Generator;
 
     /**
      * Create a ReflectionConstant for the specified $constantName.
@@ -49,7 +50,7 @@ public function reflectConstant(string $identifierName): ReflectionConstant;
     /**
      * Get all the constants available in the scope specified by the SourceLocator.
      *
-     * @return list<ReflectionConstant>
+     * @return Generator<ReflectionConstant>
      */
-    public function reflectAllConstants(): iterable;
+    public function reflectAllConstants(): Generator;
 }
diff --git a/src/SourceLocator/Type/AbstractSourceLocator.php b/src/SourceLocator/Type/AbstractSourceLocator.php
index cfc2aadda..27fdb6091 100644
--- a/src/SourceLocator/Type/AbstractSourceLocator.php
+++ b/src/SourceLocator/Type/AbstractSourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
@@ -54,15 +55,15 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
      *
      * @throws ParseToAstFailure
      */
-    final public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    final public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
         $locatedSource = $this->createLocatedSource(new Identifier(Identifier::WILDCARD, $identifierType));
 
         if (! $locatedSource) {
-            return [];
+            return;
         }
 
-        return $this->astLocator->findReflectionsOfType(
+        yield from $this->astLocator->findReflectionsOfType(
             $reflector,
             $locatedSource,
             $identifierType,
diff --git a/src/SourceLocator/Type/AggregateSourceLocator.php b/src/SourceLocator/Type/AggregateSourceLocator.php
index a5a760093..a457a9b4c 100644
--- a/src/SourceLocator/Type/AggregateSourceLocator.php
+++ b/src/SourceLocator/Type/AggregateSourceLocator.php
@@ -4,14 +4,12 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
 use Roave\BetterReflection\Reflector\Reflector;
 
-use function array_map;
-use function array_merge;
-
 class AggregateSourceLocator implements SourceLocator
 {
     /** @param list<SourceLocator> $sourceLocators */
@@ -32,14 +30,10 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
         return null;
     }
 
-    /**
-     * {@inheritDoc}
-     */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return array_merge(
-            [],
-            ...array_map(static fn (SourceLocator $sourceLocator): array => $sourceLocator->locateIdentifiersByType($reflector, $identifierType), $this->sourceLocators),
-        );
+        foreach ($this->sourceLocators as $sourceLocator) {
+            yield from $sourceLocator->locateIdentifiersByType($reflector, $identifierType);
+        }
     }
 }
diff --git a/src/SourceLocator/Type/AnonymousClassObjectSourceLocator.php b/src/SourceLocator/Type/AnonymousClassObjectSourceLocator.php
index 23734964b..0558594cd 100644
--- a/src/SourceLocator/Type/AnonymousClassObjectSourceLocator.php
+++ b/src/SourceLocator/Type/AnonymousClassObjectSourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use PhpParser\Node;
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\NodeTraverser;
@@ -25,7 +26,6 @@
 use Roave\BetterReflection\SourceLocator\Located\AnonymousLocatedSource;
 use Roave\BetterReflection\Util\FileHelper;
 
-use function array_filter;
 use function assert;
 use function file_get_contents;
 use function str_contains;
@@ -55,9 +55,14 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
      *
      * @throws ParseToAstFailure
      */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return array_filter([$this->getReflectionClass($reflector, $identifierType)]);
+        $reflection = $this->getReflectionClass($reflector, $identifierType);
+        if (! $reflection) {
+            return;
+        }
+
+        yield $reflection;
     }
 
     private function getReflectionClass(Reflector $reflector, IdentifierType $identifierType): ReflectionClass|null
diff --git a/src/SourceLocator/Type/ClosureSourceLocator.php b/src/SourceLocator/Type/ClosureSourceLocator.php
index 74cc006f1..043549008 100644
--- a/src/SourceLocator/Type/ClosureSourceLocator.php
+++ b/src/SourceLocator/Type/ClosureSourceLocator.php
@@ -5,6 +5,7 @@
 namespace Roave\BetterReflection\SourceLocator\Type;
 
 use Closure;
+use Generator;
 use PhpParser\Node;
 use PhpParser\Node\Stmt\Namespace_;
 use PhpParser\NodeTraverser;
@@ -26,7 +27,6 @@
 use Roave\BetterReflection\SourceLocator\Located\AnonymousLocatedSource;
 use Roave\BetterReflection\Util\FileHelper;
 
-use function array_filter;
 use function assert;
 use function file_get_contents;
 use function str_contains;
@@ -56,9 +56,14 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
      *
      * @throws ParseToAstFailure
      */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return array_filter([$this->getReflectionFunction($reflector, $identifierType)]);
+        $reflection = $this->getReflectionFunction($reflector, $identifierType);
+        if (! $reflection) {
+            return;
+        }
+
+        yield $reflection;
     }
 
     private function getReflectionFunction(Reflector $reflector, IdentifierType $identifierType): ReflectionFunction|null
diff --git a/src/SourceLocator/Type/Composer/PsrAutoloaderLocator.php b/src/SourceLocator/Type/Composer/PsrAutoloaderLocator.php
index ec6b97ca7..7ae0c7f47 100644
--- a/src/SourceLocator/Type/Composer/PsrAutoloaderLocator.php
+++ b/src/SourceLocator/Type/Composer/PsrAutoloaderLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type\Composer;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
@@ -54,11 +55,11 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
     /**
      * Find all identifiers of a type
      *
-     * @return list<Reflection>
+     * @return Generator<Reflection>
      */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return (new DirectoriesSourceLocator(
+        yield from (new DirectoriesSourceLocator(
             $this->mapping->directories(),
             $this->astLocator,
         ))->locateIdentifiersByType($reflector, $identifierType);
diff --git a/src/SourceLocator/Type/DirectoriesSourceLocator.php b/src/SourceLocator/Type/DirectoriesSourceLocator.php
index ff3256b26..dee0ddb52 100644
--- a/src/SourceLocator/Type/DirectoriesSourceLocator.php
+++ b/src/SourceLocator/Type/DirectoriesSourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use RecursiveDirectoryIterator;
 use RecursiveIteratorIterator;
 use Roave\BetterReflection\Identifier\Identifier;
@@ -55,11 +56,8 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
         return $this->aggregateSourceLocator->locateIdentifier($reflector, $identifier);
     }
 
-    /**
-     * {@inheritDoc}
-     */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return $this->aggregateSourceLocator->locateIdentifiersByType($reflector, $identifierType);
+        yield from $this->aggregateSourceLocator->locateIdentifiersByType($reflector, $identifierType);
     }
 }
diff --git a/src/SourceLocator/Type/FileIteratorSourceLocator.php b/src/SourceLocator/Type/FileIteratorSourceLocator.php
index dcd9cc0f0..c0da4ad09 100644
--- a/src/SourceLocator/Type/FileIteratorSourceLocator.php
+++ b/src/SourceLocator/Type/FileIteratorSourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use Iterator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
@@ -83,8 +84,8 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
      *
      * @throws InvalidFileLocation
      */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
-        return $this->getAggregatedSourceLocator()->locateIdentifiersByType($reflector, $identifierType);
+        yield from $this->getAggregatedSourceLocator()->locateIdentifiersByType($reflector, $identifierType);
     }
 }
diff --git a/src/SourceLocator/Type/MemoizingSourceLocator.php b/src/SourceLocator/Type/MemoizingSourceLocator.php
index 8ac20e31a..10229543b 100644
--- a/src/SourceLocator/Type/MemoizingSourceLocator.php
+++ b/src/SourceLocator/Type/MemoizingSourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
@@ -37,17 +38,23 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
             = $this->wrappedSourceLocator->locateIdentifier($reflector, $identifier);
     }
 
-    /** @return list<Reflection> */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array
+    /** @return Generator<Reflection> */
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator
     {
         $cacheKey = sprintf('%s_%s', $this->reflectorCacheKey($reflector), $this->identifierTypeToCacheKey($identifierType));
 
         if (array_key_exists($cacheKey, $this->cacheByIdentifierTypeKeyAndOid)) {
-            return $this->cacheByIdentifierTypeKeyAndOid[$cacheKey];
+            yield from $this->cacheByIdentifierTypeKeyAndOid[$cacheKey];
+
+            return;
+        }
+
+        $items = [];
+        foreach ($this->wrappedSourceLocator->locateIdentifiersByType($reflector, $identifierType) as $item) {
+            yield $items[] = $item;
         }
 
-        return $this->cacheByIdentifierTypeKeyAndOid[$cacheKey]
-            = $this->wrappedSourceLocator->locateIdentifiersByType($reflector, $identifierType);
+        $this->cacheByIdentifierTypeKeyAndOid[$cacheKey] = $items;
     }
 
     private function reflectorCacheKey(Reflector $reflector): string
diff --git a/src/SourceLocator/Type/SourceLocator.php b/src/SourceLocator/Type/SourceLocator.php
index 372b51cd6..61411a954 100644
--- a/src/SourceLocator/Type/SourceLocator.php
+++ b/src/SourceLocator/Type/SourceLocator.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\SourceLocator\Type;
 
+use Generator;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
@@ -26,7 +27,7 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
     /**
      * Find all identifiers of a type
      *
-     * @return list<Reflection>
+     * @return Generator<Reflection>
      */
-    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): array;
+    public function locateIdentifiersByType(Reflector $reflector, IdentifierType $identifierType): Generator;
 }
diff --git a/src/Util/FindReflectionOnLine.php b/src/Util/FindReflectionOnLine.php
index 24c6cac9f..f10c39d65 100644
--- a/src/Util/FindReflectionOnLine.php
+++ b/src/Util/FindReflectionOnLine.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflection\Util;
 
+use Generator;
 use InvalidArgumentException;
 use Roave\BetterReflection\Identifier\IdentifierType;
 use Roave\BetterReflection\Reflection\Reflection;
@@ -19,8 +20,6 @@
 use Roave\BetterReflection\SourceLocator\Type\SingleFileSourceLocator;
 use Roave\BetterReflection\SourceLocator\Type\SourceLocator;
 
-use function array_merge;
-
 final class FindReflectionOnLine
 {
     public function __construct(private SourceLocator $sourceLocator, private Locator $astLocator)
@@ -40,9 +39,9 @@ public function __construct(private SourceLocator $sourceLocator, private Locato
      */
     public function __invoke(string $filename, int $lineNumber): ReflectionMethod|ReflectionClass|ReflectionFunction|ReflectionConstant|Reflection|null
     {
-        $reflections = $this->computeReflections($filename);
+        $reflectionsGenerator = $this->computeReflections($filename);
 
-        foreach ($reflections as $reflection) {
+        foreach ($reflectionsGenerator as $reflection) {
             if ($reflection instanceof ReflectionClass && $this->containsLine($reflection, $lineNumber)) {
                 foreach ($reflection->getMethods() as $method) {
                     if ($this->containsLine($method, $lineNumber)) {
@@ -70,20 +69,29 @@ public function __invoke(string $filename, int $lineNumber): ReflectionMethod|Re
      *
      * @param non-empty-string $filename
      *
-     * @return list<Reflection>
+     * @return Generator<Reflection>
      *
      * @throws ParseToAstFailure
      * @throws InvalidFileLocation
      */
-    private function computeReflections(string $filename): array
+    private function computeReflections(string $filename): Generator
     {
         $singleFileSourceLocator = new SingleFileSourceLocator($filename, $this->astLocator);
         $reflector               = new DefaultReflector(new AggregateSourceLocator([$singleFileSourceLocator, $this->sourceLocator]));
 
-        return array_merge(
-            $singleFileSourceLocator->locateIdentifiersByType($reflector, new IdentifierType(IdentifierType::IDENTIFIER_CLASS)),
-            $singleFileSourceLocator->locateIdentifiersByType($reflector, new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION)),
-            $singleFileSourceLocator->locateIdentifiersByType($reflector, new IdentifierType(IdentifierType::IDENTIFIER_CONSTANT)),
+        yield from $singleFileSourceLocator->locateIdentifiersByType(
+            $reflector,
+            new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
+        );
+
+        yield from $singleFileSourceLocator->locateIdentifiersByType(
+            $reflector,
+            new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION),
+        );
+
+        yield from $singleFileSourceLocator->locateIdentifiersByType(
+            $reflector,
+            new IdentifierType(IdentifierType::IDENTIFIER_CONSTANT),
         );
     }
 
diff --git a/test/unit/Reflection/ReflectionClassTest.php b/test/unit/Reflection/ReflectionClassTest.php
index b4c928bf2..60aced7ff 100644
--- a/test/unit/Reflection/ReflectionClassTest.php
+++ b/test/unit/Reflection/ReflectionClassTest.php
@@ -1153,7 +1153,13 @@ public function testIsAnonymousWithAnonymousClassNoNamespace(): void
             $this->astLocator,
         ));
 
-        $allClassesInfo = $reflector->reflectAllClasses();
+        $generator = $reflector->reflectAllClasses();
+
+        $allClassesInfo = [];
+        foreach ($generator as $reflectionClass) {
+            $allClassesInfo[] = $reflectionClass;
+        }
+
         self::assertCount(1, $allClassesInfo);
 
         $classInfo = $allClassesInfo[0];
@@ -1171,14 +1177,17 @@ public function testIsAnonymousWithAnonymousClassInNamespace(): void
         ));
 
         $allClassesInfo = $reflector->reflectAllClasses();
-        self::assertCount(2, $allClassesInfo);
 
+        $count = 0;
         foreach ($allClassesInfo as $classInfo) {
             self::assertTrue($classInfo->isAnonymous());
             self::assertFalse($classInfo->inNamespace());
             self::assertStringStartsWith(ReflectionClass::ANONYMOUS_CLASS_NAME_PREFIX, $classInfo->getName());
             self::assertStringMatchesFormat('%sFixture/AnonymousClassInNamespace.php(%d)', $classInfo->getName());
+            ++$count;
         }
+
+        self::assertSame(2, $count);
     }
 
     public function testIsAnonymousWithNestedAnonymousClasses(): void
@@ -1189,14 +1198,17 @@ public function testIsAnonymousWithNestedAnonymousClasses(): void
         ));
 
         $allClassesInfo = $reflector->reflectAllClasses();
-        self::assertCount(3, $allClassesInfo);
 
+        $count = 0;
         foreach ($allClassesInfo as $classInfo) {
             self::assertTrue($classInfo->isAnonymous());
             self::assertFalse($classInfo->inNamespace());
             self::assertStringStartsWith(ReflectionClass::ANONYMOUS_CLASS_NAME_PREFIX, $classInfo->getName());
             self::assertStringMatchesFormat('%sFixture/NestedAnonymousClassInstances.php(%d)', $classInfo->getName());
+            ++$count;
         }
+
+        self::assertSame(3, $count);
     }
 
     public function testAnonymousClassWithParent(): void
@@ -1206,7 +1218,11 @@ public function testAnonymousClassWithParent(): void
             $this->astLocator,
         ));
 
-        $allClassesInfo = $reflector->reflectAllClasses();
+        $allClassesInfo = [];
+        foreach ($reflector->reflectAllClasses() as $classInfo) {
+            $allClassesInfo[] = $classInfo;
+        }
+
         self::assertCount(3, $allClassesInfo);
 
         $classInfo = $allClassesInfo[2];
@@ -1227,7 +1243,13 @@ public function testAnonymousClassWithParentDefinedLater(): void
             $this->astLocator,
         ));
 
-        $allClassesInfo = $reflector->reflectAllClasses();
+        $generator = $reflector->reflectAllClasses();
+
+        $allClassesInfo = [];
+        foreach ($generator as $reflectionClass) {
+            $allClassesInfo[] = $reflectionClass;
+        }
+
         self::assertCount(2, $allClassesInfo);
 
         $classInfo = $allClassesInfo[0];
@@ -1244,7 +1266,13 @@ public function testAnonymousClassWithInterface(): void
             $this->astLocator,
         ));
 
-        $allClassesInfo = $reflector->reflectAllClasses();
+        $generator = $reflector->reflectAllClasses();
+
+        $allClassesInfo = [];
+        foreach ($generator as $reflectionClass) {
+            $allClassesInfo[] = $reflectionClass;
+        }
+
         self::assertCount(3, $allClassesInfo);
 
         $classInfo = $allClassesInfo[2];
@@ -1266,7 +1294,13 @@ function createAnonymous()
 
         $reflector = new DefaultReflector(new StringSourceLocator($php, $this->astLocator));
 
-        $allClassesInfo = $reflector->reflectAllClasses();
+        $generator = $reflector->reflectAllClasses();
+
+        $allClassesInfo = [];
+        foreach ($generator as $reflectionClass) {
+            $allClassesInfo[] = $reflectionClass;
+        }
+
         self::assertCount(1, $allClassesInfo);
 
         $classInfo = $allClassesInfo[0];
diff --git a/test/unit/Reflector/DefaultReflectorTest.php b/test/unit/Reflector/DefaultReflectorTest.php
index a6688e60d..5601f83bf 100644
--- a/test/unit/Reflector/DefaultReflectorTest.php
+++ b/test/unit/Reflector/DefaultReflectorTest.php
@@ -56,10 +56,15 @@ public function testThrowsExceptionWhenClassIdentifierNotFound(): void
 
     public function testReflectAllClasses(): void
     {
-        $classes = (new DefaultReflector(
+        $generator = (new DefaultReflector(
             new SingleFileSourceLocator(__DIR__ . '/../Fixture/ExampleClass.php', $this->astLocator),
         ))->reflectAllClasses();
 
+        $classes = [];
+        foreach ($generator as $class) {
+            $classes[] = $class;
+        }
+
         self::assertContainsOnlyInstancesOf(ReflectionClass::class, $classes);
         self::assertCount(11, $classes);
     }
@@ -88,10 +93,15 @@ public function testThrowsExceptionWhenFunctionIdentifierNotFound(): void
 
     public function testReflectAllFunction(): void
     {
-        $functions = (new DefaultReflector(
+        $generator = (new DefaultReflector(
             new SingleFileSourceLocator(__DIR__ . '/../Fixture/Functions.php', $this->astLocator),
         ))->reflectAllFunctions();
 
+        $functions = [];
+        foreach ($generator as $reflection) {
+            $functions[] = $reflection;
+        }
+
         self::assertContainsOnlyInstancesOf(ReflectionFunction::class, $functions);
         self::assertCount(2, $functions);
     }
@@ -120,10 +130,15 @@ public function testThrowsExceptionWhenConstantIdentifierNotFound(): void
 
     public function testReflectAllConstants(): void
     {
-        $constants = (new DefaultReflector(
+        $generator = (new DefaultReflector(
             new SingleFileSourceLocator(__DIR__ . '/../Fixture/Constants.php', $this->astLocator),
         ))->reflectAllConstants();
 
+        $constants = [];
+        foreach ($generator as $reflection) {
+            $constants[] = $reflection;
+        }
+
         self::assertContainsOnlyInstancesOf(ReflectionConstant::class, $constants);
         self::assertCount(5, $constants);
     }
diff --git a/test/unit/SourceLocator/Type/AbstractSourceLocatorTest.php b/test/unit/SourceLocator/Type/AbstractSourceLocatorTest.php
index a7a913ae0..760c81a20 100644
--- a/test/unit/SourceLocator/Type/AbstractSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/AbstractSourceLocatorTest.php
@@ -15,6 +15,9 @@
 use Roave\BetterReflection\SourceLocator\Located\LocatedSource;
 use Roave\BetterReflection\SourceLocator\Type\AbstractSourceLocator;
 
+use function iterator_count;
+use function iterator_to_array;
+
 #[CoversClass(AbstractSourceLocator::class)]
 class AbstractSourceLocatorTest extends TestCase
 {
@@ -126,7 +129,9 @@ public function testLocateIdentifiersByTypeCallsFindReflectionsOfType(): void
             ->method('createLocatedSource')
             ->willReturn($locatedSource);
 
-        self::assertSame([$mockReflection], $sourceLocator->locateIdentifiersByType($mockReflector, $identifierType));
+        $generator = $sourceLocator->locateIdentifiersByType($mockReflector, $identifierType);
+
+        self::assertSame([$mockReflection], iterator_to_array($generator));
     }
 
     public function testLocateIdentifiersByTypeReturnsEmptyArrayWithoutTryingToFindReflectionsWhenUnableToLocateSource(): void
@@ -149,6 +154,8 @@ public function testLocateIdentifiersByTypeReturnsEmptyArrayWithoutTryingToFindR
             ->method('createLocatedSource')
             ->willReturn(null);
 
-        self::assertSame([], $sourceLocator->locateIdentifiersByType($mockReflector, $identifierType));
+        $generator = $sourceLocator->locateIdentifiersByType($mockReflector, $identifierType);
+
+        self::assertSame(0, iterator_count($generator));
     }
 }
diff --git a/test/unit/SourceLocator/Type/AggregateSourceLocatorTest.php b/test/unit/SourceLocator/Type/AggregateSourceLocatorTest.php
index 267cbd55d..dc4f9a4c3 100644
--- a/test/unit/SourceLocator/Type/AggregateSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/AggregateSourceLocatorTest.php
@@ -110,19 +110,26 @@ public function testLocateIdentifiersByTypeAggregatesSource(): void
 
         $source3 = $this->createMock(ReflectionClass::class);
 
-        $locator1->expects($this->once())->method('locateIdentifiersByType')->willReturn([]);
-        $locator2->expects($this->once())->method('locateIdentifiersByType')->willReturn([$source2]);
-        $locator3->expects($this->once())->method('locateIdentifiersByType')->willReturn([$source3]);
-        $locator4->expects($this->once())->method('locateIdentifiersByType')->willReturn([]);
+        $locator1->expects($this->once())->method('locateIdentifiersByType')->willReturnCallback(static fn () => yield from []);
+        $locator2->expects($this->once())->method('locateIdentifiersByType')->willReturnCallback(static fn () => yield $source2);
+        $locator3->expects($this->once())->method('locateIdentifiersByType')->willReturnCallback(static fn () => yield $source3);
+        $locator4->expects($this->once())->method('locateIdentifiersByType')->willReturnCallback(static fn () => yield from []);
+
+        $generator = (new AggregateSourceLocator([
+            $locator1,
+            $locator2,
+            $locator3,
+            $locator4,
+        ]))->locateIdentifiersByType($this->getMockReflector(), $identifierType);
+
+        $result = [];
+        foreach ($generator as $reflectionClass) {
+            $result[] = $reflectionClass;
+        }
 
         self::assertSame(
             [$source2, $source3],
-            (new AggregateSourceLocator([
-                $locator1,
-                $locator2,
-                $locator3,
-                $locator4,
-            ]))->locateIdentifiersByType($this->getMockReflector(), $identifierType),
+            $result,
         );
     }
 }
diff --git a/test/unit/SourceLocator/Type/AnonymousClassObjectSourceLocatorTest.php b/test/unit/SourceLocator/Type/AnonymousClassObjectSourceLocatorTest.php
index cdc9f1a04..ba662b2b8 100644
--- a/test/unit/SourceLocator/Type/AnonymousClassObjectSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/AnonymousClassObjectSourceLocatorTest.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflectionTest\SourceLocator\Type;
 
+use Generator;
 use PhpParser\Parser;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DataProvider;
@@ -25,6 +26,7 @@
 
 use function assert;
 use function is_string;
+use function iterator_count;
 use function realpath;
 use function sprintf;
 
@@ -114,12 +116,17 @@ public function testLocateIdentifierWithFunctionIdentifier(): void
     #[DataProvider('anonymousClassInstancesProvider')]
     public function testLocateIdentifiersByType(object $class, string $file, int $startLine, int $endLine): void
     {
-        /** @var list<ReflectionClass> $reflections */
-        $reflections = (new AnonymousClassObjectSourceLocator($class, $this->parser))->locateIdentifiersByType(
+        /** @var Generator<ReflectionClass> $generator */
+        $generator = (new AnonymousClassObjectSourceLocator($class, $this->parser))->locateIdentifiersByType(
             $this->reflector,
             new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
         );
 
+        $reflections = [];
+        foreach ($generator as $reflection) {
+            $reflections[] = $reflection;
+        }
+
         self::assertCount(1, $reflections);
         self::assertArrayHasKey(0, $reflections);
 
@@ -135,13 +142,13 @@ public function testLocateIdentifiersByTypeWithFunctionIdentifier(): void
         $anonymousClass = new class {
         };
 
-        /** @var list<ReflectionClass> $reflections */
+        /** @var Generator<ReflectionClass> $reflections */
         $reflections = (new AnonymousClassObjectSourceLocator($anonymousClass, $this->parser))->locateIdentifiersByType(
             $this->reflector,
             new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION),
         );
 
-        self::assertCount(0, $reflections);
+        self::assertSame(0, iterator_count($reflections));
     }
 
     public function testExceptionIfAnonymousClassNotFoundOnExpectedLine(): void
@@ -168,9 +175,12 @@ public function testExceptionIfAnonymousClassNotFoundOnExpectedLine(): void
         $coreReflectionPropertyInSourceLocatatorReflection->setAccessible(true);
         $coreReflectionPropertyInSourceLocatatorReflection->setValue($sourceLocator, $coreReflectionPropertyMock);
 
-        $this->expectException(NoAnonymousClassOnLine::class);
+        $generator = $sourceLocator->locateIdentifiersByType($this->reflector, new IdentifierType(IdentifierType::IDENTIFIER_CLASS));
 
-        $sourceLocator->locateIdentifiersByType($this->reflector, new IdentifierType(IdentifierType::IDENTIFIER_CLASS));
+        $this->expectException(NoAnonymousClassOnLine::class);
+        foreach ($generator as $reflection) {
+            continue;
+        }
     }
 
     /** @return list<array{0: string, 1: object}> */
diff --git a/test/unit/SourceLocator/Type/ClosureSourceLocatorTest.php b/test/unit/SourceLocator/Type/ClosureSourceLocatorTest.php
index 7e2d31e54..9b0c19e7c 100644
--- a/test/unit/SourceLocator/Type/ClosureSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/ClosureSourceLocatorTest.php
@@ -5,6 +5,7 @@
 namespace Roave\BetterReflectionTest\SourceLocator\Type;
 
 use Closure;
+use Generator;
 use PhpParser\Parser;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DataProvider;
@@ -26,6 +27,7 @@
 
 use function assert;
 use function is_string;
+use function iterator_count;
 use function realpath;
 use function sprintf;
 
@@ -105,12 +107,17 @@ public function testEvaledClosureThrowsInvalidFileLocation(): void
     #[DataProvider('closuresProvider')]
     public function testLocateIdentifiersByType(Closure $closure, string|null $namespace, string $file, int $startLine, int $endLine): void
     {
-        /** @var list<ReflectionFunction> $reflections */
-        $reflections = (new ClosureSourceLocator($closure, $this->parser))->locateIdentifiersByType(
+        /** @var Generator<ReflectionFunction> $generator */
+        $generator = (new ClosureSourceLocator($closure, $this->parser))->locateIdentifiersByType(
             $this->reflector,
             new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION),
         );
 
+        $reflections = [];
+        foreach ($generator as $reflection) {
+            $reflections[] = $reflection;
+        }
+
         self::assertCount(1, $reflections);
         self::assertArrayHasKey(0, $reflections);
 
@@ -144,9 +151,12 @@ public function testExceptionIfClosureNotFoundOnExpectedLine(): void
         $coreReflectionPropertyInSourceLocatatorReflection->setAccessible(true);
         $coreReflectionPropertyInSourceLocatatorReflection->setValue($sourceLocator, $coreReflectionPropertyMock);
 
-        $this->expectException(NoClosureOnLine::class);
+        $generator = $sourceLocator->locateIdentifiersByType($this->reflector, new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION));
 
-        $sourceLocator->locateIdentifiersByType($this->reflector, new IdentifierType(IdentifierType::IDENTIFIER_FUNCTION));
+        $this->expectException(NoClosureOnLine::class);
+        foreach ($generator as $reflection) {
+            continue;
+        }
     }
 
     public function testLocateIdentifiersByTypeWithClassIdentifier(): void
@@ -160,7 +170,7 @@ public function testLocateIdentifiersByTypeWithClassIdentifier(): void
             new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
         );
 
-        self::assertCount(0, $reflections);
+        self::assertSame(0, iterator_count($reflections));
     }
 
     /** @return list<array{0: string, 1: Closure}> */
diff --git a/test/unit/SourceLocator/Type/Composer/PsrAutoloaderLocatorTest.php b/test/unit/SourceLocator/Type/Composer/PsrAutoloaderLocatorTest.php
index 1885e1507..eaae94f63 100644
--- a/test/unit/SourceLocator/Type/Composer/PsrAutoloaderLocatorTest.php
+++ b/test/unit/SourceLocator/Type/Composer/PsrAutoloaderLocatorTest.php
@@ -9,7 +9,6 @@
 use PHPUnit\Framework\TestCase;
 use Roave\BetterReflection\Identifier\Identifier;
 use Roave\BetterReflection\Identifier\IdentifierType;
-use Roave\BetterReflection\Reflection\Reflection;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\Reflector\Reflector;
 use Roave\BetterReflection\SourceLocator\Type\Composer\Psr\Psr4Mapping;
@@ -21,7 +20,6 @@
 use Roave\BetterReflectionTest\Assets\DirectoryScannerAssetsFoo\Foo as Foo1;
 use Roave\BetterReflectionTest\BetterReflectionSingleton;
 
-use function array_map;
 use function sort;
 
 #[CoversClass(PsrAutoloaderLocator::class)]
@@ -166,14 +164,16 @@ public function testWillLocateAllClassesInMappedPsr4Paths(): void
             Foo1::class,
         ];
 
-        $actual = array_map(
-            static fn (Reflection $reflection): string => $reflection->getName(),
-            $locator->locateIdentifiersByType(
-                new DefaultReflector($locator),
-                new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
-            ),
+        $generator = $locator->locateIdentifiersByType(
+            new DefaultReflector($locator),
+            new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
         );
 
+        $actual = [];
+        foreach ($generator as $reflection) {
+            $actual[] = $reflection->getName();
+        }
+
         // Sorting may depend on filesystem here
         sort($expected);
         sort($actual);
diff --git a/test/unit/SourceLocator/Type/DirectoriesSourceLocatorTest.php b/test/unit/SourceLocator/Type/DirectoriesSourceLocatorTest.php
index 934832c19..255f7b541 100644
--- a/test/unit/SourceLocator/Type/DirectoriesSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/DirectoriesSourceLocatorTest.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflectionTest\SourceLocator\Type;
 
+use Generator;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
@@ -17,7 +18,6 @@
 use Roave\BetterReflectionTest\Assets\DirectoryScannerAssetsFoo;
 use Roave\BetterReflectionTest\BetterReflectionSingleton;
 
-use function array_map;
 use function sort;
 use function uniqid;
 
@@ -41,18 +41,18 @@ public function setUp(): void
 
     public function testScanDirectoryClasses(): void
     {
-        /** @var list<ReflectionClass> $classes */
-        $classes = $this->sourceLocator->locateIdentifiersByType(
+        /** @var Generator<ReflectionClass> $generator */
+        $generator = $this->sourceLocator->locateIdentifiersByType(
             new DefaultReflector($this->sourceLocator),
             new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
         );
 
-        self::assertCount(4, $classes);
+        $classNames = [];
+        foreach ($generator as $reflectionClass) {
+            $classNames[] = $reflectionClass->getName();
+        }
 
-        $classNames = array_map(
-            static fn (ReflectionClass $reflectionClass): string => $reflectionClass->getName(),
-            $classes,
-        );
+        self::assertCount(4, $classNames);
 
         sort($classNames);
 
diff --git a/test/unit/SourceLocator/Type/FileIteratorSourceLocatorTest.php b/test/unit/SourceLocator/Type/FileIteratorSourceLocatorTest.php
index a13ab201b..597a5f017 100644
--- a/test/unit/SourceLocator/Type/FileIteratorSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/FileIteratorSourceLocatorTest.php
@@ -5,6 +5,8 @@
 namespace Roave\BetterReflectionTest\SourceLocator\Type;
 
 use ArrayIterator;
+use FilesystemIterator;
+use Generator;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 use RecursiveDirectoryIterator;
@@ -19,7 +21,6 @@
 use Roave\BetterReflectionTest\BetterReflectionSingleton;
 use stdClass;
 
-use function array_map;
 use function sort;
 
 #[CoversClass(FileIteratorSourceLocator::class)]
@@ -34,7 +35,7 @@ public function setUp(): void
         $this->sourceLocator = new FileIteratorSourceLocator(
             new RecursiveIteratorIterator(new RecursiveDirectoryIterator(
                 __DIR__ . '/../../Assets/DirectoryScannerAssets',
-                RecursiveDirectoryIterator::SKIP_DOTS,
+                FilesystemIterator::SKIP_DOTS,
             ), RecursiveIteratorIterator::SELF_FIRST),
             BetterReflectionSingleton::instance()->astLocator(),
         );
@@ -42,18 +43,18 @@ public function setUp(): void
 
     public function testScanDirectoryClasses(): void
     {
-        /** @var list<ReflectionClass> $classes */
+        /** @var Generator<ReflectionClass> $classes */
         $classes = $this->sourceLocator->locateIdentifiersByType(
             new DefaultReflector($this->sourceLocator),
             new IdentifierType(IdentifierType::IDENTIFIER_CLASS),
         );
 
-        self::assertCount(2, $classes);
+        $classNames = [];
+        foreach ($classes as $reflectionClass) {
+            $classNames[] = $reflectionClass->getName();
+        }
 
-        $classNames = array_map(
-            static fn (ReflectionClass $reflectionClass): string => $reflectionClass->getName(),
-            $classes,
-        );
+        self::assertCount(2, $classNames);
 
         sort($classNames);
 
diff --git a/test/unit/SourceLocator/Type/MemoizingSourceLocatorTest.php b/test/unit/SourceLocator/Type/MemoizingSourceLocatorTest.php
index 6263ee2cd..31c4422b1 100644
--- a/test/unit/SourceLocator/Type/MemoizingSourceLocatorTest.php
+++ b/test/unit/SourceLocator/Type/MemoizingSourceLocatorTest.php
@@ -4,6 +4,7 @@
 
 namespace Roave\BetterReflectionTest\SourceLocator\Type;
 
+use Generator;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
@@ -20,6 +21,7 @@
 use function array_unique;
 use function count;
 use function in_array;
+use function iterator_count;
 use function random_int;
 use function range;
 use function spl_object_id;
@@ -134,36 +136,98 @@ public function testMemoizationByTypeDistinguishesBetweenSourceLocatorsAndType()
             ) use (
                 $symbols1,
                 $symbols2,
-            ): array {
+            ): Generator {
                 if ($reflector === $this->reflector1) {
-                    return $symbols1[$identifierType->getName()];
+                    yield from $symbols1[$identifierType->getName()];
+
+                    return;
                 }
 
-                return $symbols2[$identifierType->getName()];
+                yield from $symbols2[$identifierType->getName()];
             });
 
         foreach ($types as $type) {
+            $generator = $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $type);
+
+            $reflections1 = [];
+            foreach ($generator as $reflection) {
+                $reflections1[] = $reflection;
+            }
+
             self::assertSame(
                 $symbols1[$type->getName()],
-                $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $type),
+                $reflections1,
             );
+
+            $generator = $this->memoizingLocator->locateIdentifiersByType($this->reflector2, $type);
+
+            $reflections2 = [];
+            foreach ($generator as $reflection) {
+                $reflections2[] = $reflection;
+            }
+
             self::assertSame(
                 $symbols2[$type->getName()],
-                $this->memoizingLocator->locateIdentifiersByType($this->reflector2, $type),
+                $reflections2,
             );
 
             // second execution - ensures that memoization is in place
+            $generator = $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $type);
+
+            $reflections1 = [];
+            foreach ($generator as $reflection) {
+                $reflections1[] = $reflection;
+            }
+
             self::assertSame(
                 $symbols1[$type->getName()],
-                $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $type),
+                $reflections1,
             );
+
+            $generator = $this->memoizingLocator->locateIdentifiersByType($this->reflector2, $type);
+
+            $reflections2 = [];
+            foreach ($generator as $reflection) {
+                $reflections2[] = $reflection;
+            }
+
             self::assertSame(
                 $symbols2[$type->getName()],
-                $this->memoizingLocator->locateIdentifiersByType($this->reflector2, $type),
+                $reflections2,
             );
         }
     }
 
+    public function testNotCompletedMemoization(): void
+    {
+        $this
+            ->wrappedLocator
+            ->expects($this->exactly(2))
+            ->method('locateIdentifiersByType')
+            ->with($this->reflector1)
+            ->willReturnCallback(function (): Generator {
+                yield from [
+                    $this->createMock(Reflection::class),
+                    $this->createMock(Reflection::class),
+                    $this->createMock(Reflection::class),
+                ];
+            });
+
+        $classType = new IdentifierType(IdentifierType::IDENTIFIER_CLASS);
+
+        $generator = $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $classType);
+
+        // Started iterating but did not complete the operation
+        $generator->next();
+
+        // The cache will not be saved until we have completed all iterations
+        $generator2 = $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $classType);
+        $this->assertSame(3, iterator_count($generator2));
+
+        $generator3 = $this->memoizingLocator->locateIdentifiersByType($this->reflector1, $classType);
+        $this->assertSame(3, iterator_count($generator3));
+    }
+
     /**
      * @param list<Identifier> $identifiers
      * @param list<Reflector>  $reflectors