Add each()

src/Standard.php

@@ -1121,4 +1121,19 @@ public function finalVariance(
 
         return $variance;
     }
+
+    public function each(callable $func): void
+    {
+        if ($this->empty()) {
+            return;
+        }
+
+        try {
+            foreach ($this->pipeline as $item) {
+                $func($item);
+            }
+        } finally {
+            $this->discard();
+        }
+    }
 }

tests/EachTest.php

@@ -0,0 +1,111 @@
+<?php
+/**
+ * Copyright 2017, 2018 Alexey Kopytko <alexey@kopytko.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+declare(strict_types=1);
+
+namespace Tests\Pipeline;
+
+use LogicException;
+use PHPUnit\Framework\TestCase;
+use Pipeline\Standard;
+use function Pipeline\map;
+use function Pipeline\take;
+
+/**
+ * @covers \Pipeline\Standard
+ *
+ * @internal
+ */
+final class EachTest extends TestCase
+{
+    private array $output;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->output = [];
+    }
+
+    protected function spy($value): void
+    {
+        $this->output[] = $value;
+    }
+
+    public function testUninitialized(): void
+    {
+        $pipeline = new Standard();
+
+        $pipeline->each(fn ($value) => $this->spy($value));
+
+        $this->assertSame([], $this->output);
+    }
+
+    public function testEmpty(): void
+    {
+        $pipeline = take([]);
+
+        $pipeline->each(fn ($value) => $this->spy($value));
+
+        $this->assertSame([], $this->output);
+    }
+
+    public function testEmptyGenerator(): void
+    {
+        $pipeline = map(static fn () => yield from []);
+
+        $pipeline->each(fn ($value) => $this->spy($value));
+
+        $this->assertSame([], $this->output);
+    }
+
+    public function testNotEmpty(): void
+    {
+        $pipeline = take([1, 2, 3, 4]);
+
+        $pipeline->each(fn (int $value) => $this->spy($value));
+
+        $this->assertSame([1, 2, 3, 4], $this->output);
+    }
+
+    public function testInterrupt(): void
+    {
+        $pipeline = map(fn () => yield from [1, 2, 3, 4]);
+
+        $pipeline->cast(function (int $value) {
+            if (3 === $value) {
+                throw new LogicException();
+            }
+
+            return $value;
+        });
+
+        try {
+            $pipeline->each(function (int $value): void {
+                $this->spy($value);
+            });
+        } catch (LogicException $_) {
+            $this->assertSame([1, 2], $this->output);
+        }
+
+        $pipeline->each(function (int $value): void {
+            $this->spy($value);
+        });
+
+        $this->assertSame([1, 2], $this->output);
+        $this->assertSame([], $pipeline->toArray());
+    }
+}