refactor: Introduce MultipleIterableIterator.

loophp · Dec 20, 2020 · aa7701d · aa7701d
1 parent 4390145
commit aa7701d
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Showing 4 changed files with 42 additions and 14 deletions.
diff --git a/src/Iterator/MultipleIterableIterator.php b/src/Iterator/MultipleIterableIterator.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace loophp\collection\Iterator;
+
+use AppendIterator;
+use NoRewindIterator;
+
+/**
+ * @internal
+ *
+ * @psalm-template TKey
+ * @psalm-template T
+ *
+ * @extends ProxyIterator<TKey, T>
+ */
+final class MultipleIterableIterator extends ProxyIterator
+{
+    /**
+     * @psalm-param iterable<TKey, T> $iterable
+     */
+    public function __construct(iterable ...$iterators)
+    {
+        $appendIterator = new AppendIterator();
+
+        foreach ($iterators as $iterator) {
+            $appendIterator->append(new NoRewindIterator(new IterableIterator($iterator)));
+        }
+
+        $this->iterator = $appendIterator;
+    }
+}
diff --git a/src/Operation/Append.php b/src/Operation/Append.php
@@ -7,6 +7,7 @@
 use Closure;
 use Generator;
 use Iterator;
+use loophp\collection\Iterator\MultipleIterableIterator;
 
 /**
  * @psalm-template TKey
@@ -32,10 +33,8 @@ public function __invoke(): Closure
                  *
                  * @psalm-return Generator<int|TKey, T>
                  */
-                static function (Iterator $iterator) use ($items): Generator {
-                    yield from $iterator;
-
-                    return yield from $items;
+                static function (Iterator $iterator) use ($items): Iterator {
+                    return new MultipleIterableIterator($iterator, $items);
                 };
     }
 }
diff --git a/src/Operation/Merge.php b/src/Operation/Merge.php
@@ -7,6 +7,7 @@
 use Closure;
 use Generator;
 use Iterator;
+use loophp\collection\Iterator\MultipleIterableIterator;
 
 /**
  * @psalm-template TKey
@@ -30,12 +31,8 @@ public function __invoke(): Closure
                  *
                  * @psalm-return Generator<TKey, T>
                  */
-                static function (Iterator $iterator) use ($sources): Generator {
-                    yield from $iterator;
-
-                    foreach ($sources as $source) {
-                        yield from $source;
-                    }
+                static function (Iterator $iterator) use ($sources): Iterator {
+                    return new MultipleIterableIterator($iterator, ...$sources);
                 };
     }
 }
diff --git a/src/Operation/Prepend.php b/src/Operation/Prepend.php
@@ -7,6 +7,7 @@
 use Closure;
 use Generator;
 use Iterator;
+use loophp\collection\Iterator\MultipleIterableIterator;
 
 /**
  * @psalm-template TKey
@@ -32,10 +33,8 @@ public function __invoke(): Closure
                  *
                  * @psalm-return Generator<int|TKey, T>
                  */
-                static function (Iterator $iterator) use ($items): Generator {
-                    yield from $items;
-
-                    return yield from $iterator;
+                static function (Iterator $iterator) use ($items): Iterator {
+                    return new MultipleIterableIterator($items, $iterator);
                 };
     }
 }