add RecursiveIteratorAggregateIterator

phpstan-baseline.neon

@@ -1,16 +1,25 @@
 parameters:
-	ignoreErrors:
-		-
-			message: "#^While loop condition is always true\\.$#"
-			count: 1
-			path: src/RandomIntegerAggregate.php
+    ignoreErrors:
+        -
+            message: "#^While loop condition is always true\\.$#"
+            count: 1
+            path: src/RandomIntegerAggregate.php
 
-		-
-			message: "#^Parameter \\#1 \\$iterable of class loophp\\\\iterators\\\\UnpackIterableAggregate constructor expects iterable\\<\\(int\\|string\\), array\\{TKey, T\\}\\>, loophp\\\\iterators\\\\UnpackIterableAggregate\\<array\\{TKey, T\\}\\|int\\|null, array\\{TKey, T\\}\\|int\\|null\\> given\\.$#"
-			count: 1
-			path: src/RandomIterableAggregate.php
+        -
+            message: "#^Parameter \\#1 \\$iterable of class loophp\\\\iterators\\\\UnpackIterableAggregate constructor expects iterable\\<\\(int\\|string\\), array\\{TKey, T\\}\\>, loophp\\\\iterators\\\\UnpackIterableAggregate\\<array\\{TKey, T\\}\\|int\\|null, array\\{TKey, T\\}\\|int\\|null\\> given\\.$#"
+            count: 1
+            path: src/RandomIterableAggregate.php
 
-		-
-			message: "#^Parameter \\#1 \\$iterable of class loophp\\\\iterators\\\\UnpackIterableAggregate constructor expects iterable\\<\\(int\\|string\\), array\\{array\\{TKey, T\\}\\|int\\|null, array\\{TKey, T\\}\\|int\\|null\\}\\>, loophp\\\\iterators\\\\SortIterableAggregate\\<array\\<int, int\\|null\\>, array\\<int, array\\{TKey, T\\}\\|int\\|null\\>\\> given\\.$#"
-			count: 1
-			path: src/RandomIterableAggregate.php
+        -
+            message: "#^Parameter \\#1 \\$iterable of class loophp\\\\iterators\\\\UnpackIterableAggregate constructor expects iterable\\<\\(int\\|string\\), array\\{array\\{TKey, T\\}\\|int\\|null, array\\{TKey, T\\}\\|int\\|null\\}\\>, loophp\\\\iterators\\\\SortIterableAggregate\\<array\\<int, int\\|null\\>, array\\<int, array\\{TKey, T\\}\\|int\\|null\\>\\> given\\.$#"
+            count: 1
+            path: src/RandomIterableAggregate.php
+        -
+            message: "#^Method loophp\\\\iterators\\\\RecursiveIteratorAggregateIterator\\:\\:findIterator\\(\\) has parameter \\$input with no value type specified in iterable type Traversable\\.$#"
+            count: 1
+            path: src/RecursiveIteratorAggregateIterator.php
+
+        -
+            message: "#^Method loophp\\\\iterators\\\\RecursiveIteratorAggregateIterator\\:\\:findIterator\\(\\) should return Iterator but returns Traversable\\.$#"
+            count: 1
+            path: src/RecursiveIteratorAggregateIterator.php

src/RecursiveIteratorAggregateIterator.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+namespace loophp\iterators;
+
+use Generator;
+use Iterator;
+use IteratorAggregate;
+use RuntimeException;
+use Traversable;
+
+use function count;
+
+/**
+ * @template TKey
+ * @template T
+ *
+ * @implements IteratorAggregate<int, T>
+ */
+class RecursiveIteratorAggregateIterator implements IteratorAggregate
+{
+    /**
+     * @var list<Iterator>
+     */
+    private array $stack = [];
+
+    /**
+     * @param Traversable<TKey,T> $input
+     */
+    public function __construct(private readonly Traversable $input) {}
+
+    public function getDepth(): int
+    {
+        return count($this->stack) - 1;
+    }
+
+    /**
+     * @return Generator<int,T>
+     */
+    public function getIterator(): Generator
+    {
+        $this->stack = [self::findIterator($this->input)];
+
+        while (true) {
+            while (count($this->stack) > 0 && !end($this->stack)->valid()) {
+                array_pop($this->stack);
+            }
+
+            if (count($this->stack) === 0) {
+                return;
+            }
+            $current = end($this->stack)->current();
+
+            yield $current;
+            end($this->stack)->next();
+            $this->stack[] = self::findIterator($current);
+        }
+    }
+
+    private static function findIterator(Traversable $input): Iterator
+    {
+        $prev = null;
+
+        while (!($input instanceof Iterator)) {
+            if ($prev === $input || !($input instanceof IteratorAggregate)) {
+                throw new RuntimeException('Invalid iterator');
+            }
+            $prev = $input;
+            $input = $input->getIterator();
+        }
+
+        return $input;
+    }
+}

tests/unit/RecursiveIteratorAggregateIteratorTest.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace tests\loophp\iterators;
+
+use ArrayIterator;
+use IteratorAggregate;
+use loophp\iterators\RecursiveIteratorAggregateIterator;
+use PHPUnit\Framework\TestCase;
+use Traversable;
+
+class RecursiveIteratorAggregateIteratorTestObject implements IteratorAggregate
+{
+    public function __construct(public readonly string $name, public readonly array $items) {}
+
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator($this->items);
+    }
+}
+
+/**
+ * @internal
+ *
+ * @coversNothing
+ */
+final class RecursiveIteratorAggregateIteratorTest extends TestCase
+{
+    public function testRecursiveIteratorAggregateIterator()
+    {
+        $input = [
+            new RecursiveIteratorAggregateIteratorTestObject('1', [
+                new RecursiveIteratorAggregateIteratorTestObject('1-1', [
+                    new RecursiveIteratorAggregateIteratorTestObject('1-1-1', []),
+                ]),
+                new RecursiveIteratorAggregateIteratorTestObject('1-2', []),
+            ]),
+            new RecursiveIteratorAggregateIteratorTestObject('2', []),
+            new RecursiveIteratorAggregateIteratorTestObject('3', [
+                new RecursiveIteratorAggregateIteratorTestObject('3-1', []),
+            ]),
+        ];
+        $expected = [
+            '0: 1',
+            '1: 1-1',
+            '2: 1-1-1',
+            '1: 1-2',
+            '0: 2',
+            '0: 3',
+            '1: 3-1',
+        ];
+        $result = [];
+        $iterator = new RecursiveIteratorAggregateIterator(new ArrayIterator($input));
+
+        foreach ($iterator as $item) {
+            $result[] = $iterator->getDepth() . ': ' . $item->name;
+        }
+        self::assertSame($expected, $result);
+    }
+}