From 35ad82091dd1aeb40dbc6da88e6199a4303ff5a0 Mon Sep 17 00:00:00 2001
From: Karsten Schmidt <k@thi.ng>
Date: Tue, 2 Apr 2024 14:32:11 +0200
Subject: [PATCH] feat(api): add async types

---
 packages/api/package.json |  3 +++
 packages/api/src/async.ts | 24 ++++++++++++++++++++++++
 packages/api/src/index.ts |  1 +
 3 files changed, 28 insertions(+)
 create mode 100644 packages/api/src/async.ts

diff --git a/packages/api/package.json b/packages/api/package.json
index ac29383b9f..8483c0a313 100644
--- a/packages/api/package.json
+++ b/packages/api/package.json
@@ -81,6 +81,9 @@
 		"./assoc": {
 			"default": "./assoc.js"
 		},
+		"./async": {
+			"default": "./async.js"
+		},
 		"./bind": {
 			"default": "./bind.js"
 		},
diff --git a/packages/api/src/async.ts b/packages/api/src/async.ts
new file mode 100644
index 0000000000..6512d71f33
--- /dev/null
+++ b/packages/api/src/async.ts
@@ -0,0 +1,24 @@
+import type { Fn, Fn0, Fn2 } from "./fn.js";
+
+export type MaybePromise<T> = T | Promise<T>;
+
+export type MaybeAsyncIterable<T> = Iterable<T> | AsyncIterable<T>;
+
+export type MaybeAsyncGenerator<T> =
+	| IterableIterator<T>
+	| AsyncIterableIterator<T>;
+
+export type AsyncPredicate<T> = Fn<T, Promise<boolean>>;
+
+export type AsyncPredicate2<T> = Fn2<T, T, Promise<boolean>>;
+
+export type AsyncStatefulPredicate<T> = Fn0<AsyncPredicate<T>>;
+
+export type AsyncStatefulPredicate2<T> = Fn0<AsyncPredicate2<T>>;
+
+/**
+ * Async version of {@link identity}.
+ *
+ * @param x
+ */
+export const asyncIdentity = async <T>(x: T) => x;
diff --git a/packages/api/src/index.ts b/packages/api/src/index.ts
index 154bfbe5d1..d26d5b70d1 100644
--- a/packages/api/src/index.ts
+++ b/packages/api/src/index.ts
@@ -1,4 +1,5 @@
 export * from "./assoc.js";
+export * from "./async.js";
 export * from "./bind.js";
 export * from "./buffered.js";
 export * from "./clear.js";