From e717d1d0cbfb839b6c06bcf9bf50f5af5f4a30a9 Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <me@steffo.eu>
Date: Mon, 2 May 2022 15:57:17 +0200
Subject: [PATCH] Document `AsyncFilter`

---
 royalnet/royaltyping.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/royalnet/royaltyping.py b/royalnet/royaltyping.py
index b64302a7..f228989b 100644
--- a/royalnet/royaltyping.py
+++ b/royalnet/royaltyping.py
@@ -36,6 +36,10 @@ of :class:`str` to :data:`.JSON` mappings.
 """
 
 AsyncFilter = Callable[[Any], Awaitable[Any]]
+"""
+A function taking an item as input, and returning it in a different form after being awaited.
+"""
+
 
 class ConversationProtocol(Protocol):
     def __call__(self, **kwargs) -> Awaitable[None]: