From e1d91ec45955777b0b2e25d26c8dadd6d03013d1 Mon Sep 17 00:00:00 2001
From: Pol Dellaiera <pol.dellaiera@protonmail.com>
Date: Wed, 30 Dec 2020 13:51:09 +0100
Subject: [PATCH] refactor: Simplify operations.

---
 src/Operation/Drop.php     |  6 +++---
 src/Operation/ScanLeft.php | 27 ++++++++-------------------
 2 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/src/Operation/Drop.php b/src/Operation/Drop.php
index aba55efac..56c091dc9 100644
--- a/src/Operation/Drop.php
+++ b/src/Operation/Drop.php
@@ -32,12 +32,12 @@ public function __invoke(): Closure
                  *
                  * @psalm-return Generator<TKey, T>
                  */
-                static function (Iterator $iterator) use ($offsets): Generator {
-                    if (!$iterator->valid()) {
+                static function (Iterator $iterator) use ($offsets): Iterator {
+                    if (false === $iterator->valid()) {
                         return new EmptyIterator();
                     }
 
-                    return yield from new LimitIterator($iterator, array_sum($offsets));
+                    return new LimitIterator($iterator, array_sum($offsets));
                 };
     }
 }
diff --git a/src/Operation/ScanLeft.php b/src/Operation/ScanLeft.php
index 3d3d6bf29..c0a88c513 100644
--- a/src/Operation/ScanLeft.php
+++ b/src/Operation/ScanLeft.php
@@ -35,25 +35,14 @@ public function __invoke(): Closure
                  *
                  * @psalm-return Closure(Iterator<TKey, T>): Generator<int|TKey, T|null>
                  */
-                static fn ($initial = null): Closure =>
-                    /**
-                     * @psalm-param Iterator<TKey, T> $iterator
-                     *
-                     * @psalm-return Generator<int|TKey, T|null>
-                     */
-                    static function (Iterator $iterator) use ($callback, $initial): Generator {
-                        // @todo: See if we cannot find a better way to do this.
-                        if (false === $iterator->valid()) {
-                            return yield from [];
-                        }
+                static function ($initial = null) use ($callback): Closure {
+                    /** @psalm-var Closure(Iterator<TKey, T>): Generator<int|TKey, T|null> $pipe */
+                    $pipe = Pipe::of()(
+                        Reduction::of()($callback)($initial),
+                        Prepend::of()($initial)
+                    );
 
-                        /** @psalm-var Closure(Iterator<TKey, T>): Generator<int|TKey, T|null> $pipe */
-                        $pipe = Pipe::of()(
-                            Reduction::of()($callback)($initial),
-                            Prepend::of()($initial)
-                        );
-
-                        return yield from $pipe($iterator);
-                    };
+                    return $pipe;
+                };
     }
 }