Implements Monoid interface/typeclass.

marcosh · Oct 19, 2021 · 27c4ae0 · 27c4ae0
1 parent ae0dab4
commit 27c4ae0
Showing 1 changed file with 20 additions and 0 deletions.
diff --git a/src/Typeclass/Monoid.php b/src/Typeclass/Monoid.php
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+<?php
+
+declare(strict_types=1);
+
+namespace Marcosh\LamPHPda\Typeclass;
+
+/**
+ * @psalm-immutable
+ *
+ * @template A
+ */
+interface Monoid extends Semigroup
+{
+    /**
+     * @psalm-pure
+     *
+     * @return Monoid<A>
+     */
+    public static function mempty(): Monoid;
+}