Add proveUnion function

Author: klimick

composer.json

@@ -87,6 +87,7 @@
             "src/Fp/Functions/Collection/Tail.php",
             "src/Fp/Functions/Collection/Zip.php",
             "src/Fp/Functions/Collection/MkString.php",
+            "src/Fp/Functions/Evidence/ProveUnion.php",
             "src/Fp/Functions/Evidence/ProveNull.php",
             "src/Fp/Functions/Evidence/ProveArray.php",
             "src/Fp/Functions/Evidence/ProveBool.php",

src/Fp/Functions/Evidence/ProveUnion.php

@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Fp\Evidence;
+
+use Closure;
+use Fp\Functional\Option\Option;
+
+use function Fp\Collection\firstMap;
+
+/**
+ * Prove that subject is one of given types
+ *
+ * ```php
+ * >>> proveUnion(1, [proveString(...), proveInt(...)]);
+ * => Some(1)
+ * >>> proveUnion('str', [proveString(...), proveInt(...)]);
+ * => Some('str')
+ * >>> proveUnion(0.42, [proveString(...), proveInt(...)]);
+ * => None
+ * ```
+ *
+ * @template T
+ *
+ * @param non-empty-list<Closure(mixed): Option<T>> $evidences
+ * @return Option<T>
+ */
+function proveUnion(mixed $subject, array $evidences): Option
+{
+    return firstMap($evidences, fn(Closure $prove) => $prove($subject));
+}
+
+/**
+ * Curried version of {@see proveUnion()}
+ *
+ * ```php
+ * >>> union([proveString(...), proveInt(...)])(1);
+ * => Some(1)
+ * >>> union([proveString(...), proveInt(...)])('str');
+ * => Some('str')
+ * >>> union([proveString(...), proveInt(...)])(0.42);
+ * => None
+ * ```
+ *
+ * @template T
+ *
+ * @param non-empty-list<Closure(mixed): Option<T>> $evidences
+ * @return Closure(mixed): Option<T>
+ */
+function union(array $evidences): Closure
+{
+    return fn(mixed $subject) => proveUnion($subject, $evidences);
+}
+
+/**
+ * Curried and varargs version of {@see proveUnion()}
+ *
+ * ```php
+ * >>> unionT(proveString(...), proveInt(...))(1);
+ * => Some(1)
+ * >>> unionT(proveString(...), proveInt(...))('str');
+ * => Some('str')
+ * >>> unionT(proveString(...), proveInt(...))(0.42);
+ * => None
+ * ```
+ *
+ * @template T
+ *
+ * @param Closure(mixed): Option<T> $evidence
+ * @param Closure(mixed): Option<T> ...$evidences
+ * @return Closure(mixed): Option<T>
+ */
+function unionT(Closure $evidence, Closure ...$evidences): Closure
+{
+    return fn(mixed $subject) => proveUnion($subject, [$evidence, ...$evidences]);
+}

tests/Runtime/Functions/Evidence/ProveUnionTest.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Runtime\Functions\Evidence;
+
+use Fp\Functional\Option\Option;
+use PHPUnit\Framework\TestCase;
+
+use function Fp\Evidence\proveInt;
+use function Fp\Evidence\proveNull;
+use function Fp\Evidence\proveString;
+use function Fp\Evidence\proveUnion;
+use function Fp\Evidence\union;
+use function Fp\Evidence\unionT;
+
+final class ProveUnionTest extends TestCase
+{
+    public function testProveUnion(): void
+    {
+        $evidences = [
+            proveInt(...),
+            proveString(...),
+            proveNull(...),
+        ];
+
+        $this->assertEquals(Option::none(), proveUnion(42.00, $evidences));
+        $this->assertEquals(Option::none(), proveUnion([42], $evidences));
+        $this->assertEquals(Option::some(42), proveUnion(42, $evidences));
+        $this->assertEquals(Option::some('str'), proveUnion('str', $evidences));
+        $this->assertEquals(Option::some(null), proveUnion(null, $evidences));
+    }
+
+    public function testUnion(): void
+    {
+        $evidences = [
+            proveInt(...),
+            proveString(...),
+            proveNull(...),
+        ];
+
+        $this->assertEquals(Option::none(), union($evidences)(42.00));
+        $this->assertEquals(Option::none(), union($evidences)([42]));
+        $this->assertEquals(Option::some(42), union($evidences)(42));
+        $this->assertEquals(Option::some('str'), union($evidences)('str'));
+        $this->assertEquals(Option::some(null), union($evidences)(null));
+    }
+
+    public function testUnionT(): void
+    {
+        $evidences = [
+            proveInt(...),
+            proveString(...),
+            proveNull(...),
+        ];
+
+        $this->assertEquals(Option::none(), unionT(...$evidences)(42.00));
+        $this->assertEquals(Option::none(), unionT(...$evidences)([42]));
+        $this->assertEquals(Option::some(42), unionT(...$evidences)(42));
+        $this->assertEquals(Option::some('str'), unionT(...$evidences)('str'));
+        $this->assertEquals(Option::some(null), unionT(...$evidences)(null));
+    }
+}

tests/Static/Functions/Evidence/ProveUnionStaticTest.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Static\Functions\Evidence;
+
+use Fp\Functional\Option\Option;
+
+use function Fp\Evidence\proveInt;
+use function Fp\Evidence\proveString;
+use function Fp\Evidence\proveUnion;
+use function Fp\Evidence\union;
+use function Fp\Evidence\unionT;
+
+final class ProveUnionStaticTest
+{
+    /**
+     * @return Option<int|string>
+     */
+    public function proveUnion(mixed $value): Option
+    {
+        return proveUnion($value, [
+            proveInt(...),
+            proveString(...),
+        ]);
+    }
+
+    /**
+     * @return Option<int|string>
+     */
+    public function union(mixed $value): Option
+    {
+        return union([
+            proveInt(...),
+            proveString(...),
+        ])($value);
+    }
+
+    /**
+     * @return Option<int|string>
+     */
+    public function unionT(mixed $value): Option
+    {
+        return unionT(proveInt(...), proveString(...))($value);
+    }
+}