WIP

lib/cache.ts

@@ -0,0 +1,52 @@
+export type Cache<T> = Map<string, T>;
+export type AsyncCache<T> = Map<string, Promise<T>>;
+
+export function withCache<T, U extends (...args: unknown[]) => T>(
+	callback: U,
+	key: string,
+	cache: Cache<T>,
+): (...args: Parameters<U>) => T {
+	return (...args) => {
+		if (cache.has(key)) {
+			return cache.get(key) as T;
+		}
+
+		const value = callback(...args);
+		cache.set(key, value);
+
+		return value;
+	};
+}
+
+export function withAsyncCache<T, U extends (...args: unknown[]) => Promise<T>>(
+	callback: U,
+	key: string,
+	cache: AsyncCache<T>,
+): (...args: Parameters<U>) => Promise<T> {
+	return async (...args) => {
+		if (cache.has(key)) {
+			return (await cache.get(key)) as T;
+		}
+
+		const value = callback(...args);
+		cache.set(key, value);
+
+		return await value;
+	};
+}
+
+export function useWithCache<T>(
+	callback: (...args: unknown[]) => T,
+): [(uri: string) => T, Cache<T>] {
+	const cache: Cache<T> = new Map();
+
+	return [(uri: string) => withCache(callback, uri, cache)(uri), cache];
+}
+
+export function useWithAsyncCache<T>(
+	callback: (...args: unknown[]) => Promise<T>,
+): [(uri: string) => Promise<T>, AsyncCache<T>] {
+	const cache: AsyncCache<T> = new Map();
+
+	return [(uri: string) => withAsyncCache(callback, uri, cache)(uri), cache];
+}