move applyWithArity to internal namespace

composer.json

@@ -23,6 +23,7 @@
         },
         "files": [
             "./src/functions.php",
+            "./src/Internal/functions.php",
             "./src/Predicates/index.php",
             "./src/Collections/Internal/functions.php",
             "./src/Collections/Internal/containers.php",

phpstan-baseline.neon

@@ -498,18 +498,6 @@ parameters:
 			count: 1
 			path: src/Utils/index.php
 
-		-
-			message: '#^Function Kadet\\Functional\\applyWithArity\(\) has no return type specified\.$#'
-			identifier: missingType.return
-			count: 1
-			path: src/Utils/index.php
-
-		-
-			message: '#^Function Kadet\\Functional\\applyWithArity\(\) has parameter \$args with no value type specified in iterable type array\.$#'
-			identifier: missingType.iterableValue
-			count: 1
-			path: src/Utils/index.php
-
 		-
 			message: '#^Function Kadet\\Functional\\curry\(\) has parameter \$args with no type specified\.$#'
 			identifier: missingType.parameter

src/Internal/functions.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * Copyright 2026 Kacper Donat
+ *
+ * @author Kacper "Kadet" Donat <kacper@kadet.net>
+ *
+ * Full license available in separate LICENSE file
+ */
+
+namespace Kadet\Functional\Internal;
+
+use function Kadet\Functional\apply;
+use function Kadet\Functional\partial;
+
+/**
+ * The argument dispatch of apply(), with the arity of $callable already known: it calls $call when there are enough
+ * arguments and partially applies $callable otherwise.
+ *
+ * @internal
+ *
+ * @param array<mixed> $args
+ */
+function applyWithArity(callable $callable, callable $call, bool $variadic, int $required, int $all, array $args): mixed
+{
+    switch (true) {
+        case $variadic:
+            return partial($callable, ...$args);
+
+        case count($args) >= $all:
+            $applied = $call(...array_slice($args, 0, $all));
+            return is_callable($applied) ? apply($applied, ...array_slice($args, $all)) : $applied;
+
+        case count($args) >= $required:
+            return $call(...$args);
+
+        default:
+            return partial($callable, ...$args);
+    }
+}

src/Utils/FixedFunction.php

@@ -11,7 +11,7 @@ namespace Kadet\Functional\Utils;
 
 
 use function Kadet\Functional\apply;
-use function Kadet\Functional\applyWithArity;
+use function Kadet\Functional\Internal\applyWithArity;
 use Kadet\Functional\Compilable;
 use function Kadet\Functional\compile;
 use Kadet\Functional\Decorator;

src/Utils/index.php

@@ -15,6 +15,8 @@ use Kadet\Functional\Utils\FunctionPipeline;
 use Kadet\Functional\Utils\MemoizedFunction;
 use Kadet\Functional\Utils\PartiallyAppliedFunction;
 
+use function Kadet\Functional\Internal\applyWithArity;
+
 function partial(callable $callable, ...$args): PartiallyAppliedFunction
 {
     return new PartiallyAppliedFunction($callable, ...$args);
@@ -39,30 +41,6 @@ function apply(callable $callable, ...$args)
     }
 }
 
-/**
- * The argument dispatch of apply(), with the arity of $callable already known: it calls $call when there are enough
- * arguments and partially applies $callable otherwise.
- *
- * @internal
- */
-function applyWithArity(callable $callable, callable $call, bool $variadic, int $required, int $all, array $args)
-{
-    switch (true) {
-        case $variadic:
-            return partial($callable, ...$args);
-
-        case count($args) >= $all:
-            $applied = $call(...array_slice($args, 0, $all));
-            return is_callable($applied) ? apply($applied, ...array_slice($args, $all)) : $applied;
-
-        case count($args) >= $required:
-            return $call(...$args);
-
-        default:
-            return partial($callable, ...$args);
-    }
-}
-
 function curry(callable $callable, ?int $threshold = null, ...$args): CurriedFunction
 {
     return new CurriedFunction($callable, $threshold, ...$args);