Rework async strategy

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## [Unreleased]
+
+### Added
+
+- Internal `Innmind\Signals\Handler::asAsync()`
+
+### Deprecated
+
+- `Innmind\Signals\Handler::async()`
+
 ## 5.1.0 - 2026-08-16
 
 ### Changed

src/Handler.php

@@ -38,16 +38,15 @@ public static function main(): self
      * instruct the fiber to terminate.
      *
      * @internal
+     * @deprecated
      * @psalm-mutation-free
      */
     #[\NoDiscard]
     public static function async(
         self $signals,
         ?Interceptor $interceptor = null,
     ): self {
-        return new self(
-            Async::new($signals, $interceptor),
-        );
+        return $signals->asAsync($interceptor);
     }
 
     /**
@@ -71,4 +70,18 @@ public function remove(callable $listener): Attempt
     {
         return $this->implementation->remove($listener);
     }
+
+    /**
+     * This is intended to build a child handler inside a Fiber.
+     * The interceptor allows to emulate a signals to send a fake signal to
+     * instruct the fiber to terminate.
+     *
+     * @internal
+     * @psalm-mutation-free
+     */
+    #[\NoDiscard]
+    public function asAsync(?Interceptor $interceptor = null): self
+    {
+        return new self($this->implementation->asAsync($interceptor));
+    }
 }

src/Handler/Async.php

@@ -4,7 +4,6 @@
 namespace Innmind\Signals\Handler;
 
 use Innmind\Signals\{
-    Handler,
     Signal,
     Info,
     Async\Interceptor,
@@ -23,7 +22,7 @@ final class Async
      * @psalm-mutation-free
      */
     private function __construct(
-        private Handler $parent,
+        private self|Main $parent,
         private ?Interceptor $interceptor,
     ) {
     }
@@ -32,7 +31,7 @@ private function __construct(
      * @psalm-pure
      */
     #[\NoDiscard]
-    public static function new(Handler $parent, ?Interceptor $interceptor): self
+    public static function new(self|Main $parent, ?Interceptor $interceptor): self
     {
         return new self($parent, $interceptor);
     }
@@ -70,4 +69,12 @@ public function remove(callable $listener): Attempt
                 return $_;
             });
     }
+
+    /**
+     * @psalm-mutation-free
+     */
+    public function asAsync(?Interceptor $interceptor): self
+    {
+        return new self($this, $interceptor); // todo return $this when no interceptor ?
+    }
 }

src/Handler/Main.php

@@ -6,6 +6,7 @@
 use Innmind\Signals\{
     Signal,
     Info,
+    Async\Interceptor,
 };
 use Innmind\Immutable\{
     Sequence,
@@ -117,6 +118,14 @@ public function remove(callable $listener): Attempt
             });
     }
 
+    /**
+     * @psalm-mutation-free
+     */
+    public function asAsync(?Interceptor $interceptor): Async
+    {
+        return Async::new($this, $interceptor);
+    }
+
     /**
      * @return Attempt<Sequence<callable(Signal, Info): void>>
      */