From 5e33cfb2d8ef381076d03659c9812c8ce00d7293 Mon Sep 17 00:00:00 2001
From: Simon Podlipsky <simon@podlipsky.net>
Date: Tue, 14 Nov 2023 13:06:55 +0100
Subject: [PATCH] feat: better name mappedSetsFromIterable

- deprecated mappedValueSetsFromIterable
---
 src/ds.php       | 33 +++++++++++++++++++++++++++++++++
 tests/DsTest.php |  8 ++++----
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/ds.php b/src/ds.php
index ac9885c..fd278e2 100644
--- a/src/ds.php
+++ b/src/ds.php
@@ -54,6 +54,8 @@ function mapFromIterable(iterable $iterable, callable $mapper): Map
 }
 
 /**
+ * @deprecated Use {@link mappedSetsFromIterable} instead
+ *
  * @param iterable<K, V> $iterable
  * @param callable(K, V): Pair<KReturn, VReturn> $mapper
  *
@@ -84,6 +86,37 @@ function mappedValueSetsFromIterable(iterable $iterable, callable $mapper): Map
     return $map;
 }
 
+/**
+ * @param iterable<K, V> $iterable
+ * @param callable(K, V): Pair<KReturn, VReturn> $mapper
+ *
+ * @return Map<KReturn, Set<VReturn>>
+ *
+ * @template K
+ * @template V
+ * @template KReturn
+ * @template VReturn
+ */
+function mappedSetsFromIterable(iterable $iterable, callable $mapper): Map
+{
+    /** @var Map<KReturn, Set<VReturn>> $map */
+    $map = new Map();
+
+    foreach ($iterable as $key => $value) {
+        $keyValue = $mapper($key, $value);
+        $set = $map->get($keyValue->key, null);
+        if ($set === null) {
+            /** @var Set<VReturn> $set */
+            $set = new Set();
+            $map->put($keyValue->key, $set);
+        }
+
+        $set->add($keyValue->value);
+    }
+
+    return $map;
+}
+
 /**
  * @param iterable<K, V> $iterable
  * @param callable(K,V): VReturn $mapper
diff --git a/tests/DsTest.php b/tests/DsTest.php
index b5602a6..2b9d32b 100644
--- a/tests/DsTest.php
+++ b/tests/DsTest.php
@@ -11,12 +11,12 @@
 
 use function Cdn77\Functions\mapFromEntries;
 use function Cdn77\Functions\mapFromIterable;
-use function Cdn77\Functions\mappedValueSetsFromIterable;
+use function Cdn77\Functions\mappedSetsFromIterable;
 use function Cdn77\Functions\setFromIterable;
 use function Cdn77\Functions\vectorFromIterable;
 
 #[CoversFunction('Cdn77\Functions\mapFromIterable')]
-#[CoversFunction('Cdn77\Functions\mappedValueSetsFromIterable')]
+#[CoversFunction('Cdn77\Functions\mappedSetsFromIterable')]
 #[CoversFunction('Cdn77\Functions\setFromIterable')]
 #[CoversFunction('Cdn77\Functions\vectorFromIterable')]
 final class DsTest extends TestCase
@@ -53,7 +53,7 @@ public function testMapFromIterable(): void
         self::assertFalse($map->get(4));
     }
 
-    public function testMappedValueSetsFromIterable(): void
+    public function testMappedSetsFromIterable(): void
     {
         /** @var callable():Generator<int, string> $iterableFactory */
         $iterableFactory = static function (): Generator {
@@ -63,7 +63,7 @@ public function testMappedValueSetsFromIterable(): void
             yield 2 => 'b';
         };
 
-        $map = mappedValueSetsFromIterable(
+        $map = mappedSetsFromIterable(
             $iterableFactory(),
             static fn (int $key, string $value) => new Pair($key * 2, $value . '_')
         );