Work on experimental storage system

experiments/res1.mjs

@@ -0,0 +1,65 @@
+import { inspect } from 'node:util';
+
+class Item_Unresolvable extends Error {
+	constructor(data) {
+		const { resolver, item } = data;
+		const type = item === null ? 'null' : typeof item;
+		super(`Cannot resolve item ${inspect(item)} of type "${type}" using resolver ${resolver}`);
+		this.data = data;
+	}
+}
+
+class Abstract_Resolver {
+	resolve(item) {
+		const handler = this.resolve_handler(item);
+		if (!handler) {
+			throw new Item_Unresolvable({ resolver: this, item });
+		}
+		return handler({ resolver: this, item });
+	}
+}
+
+class Chained_Resolver extends Abstract_Resolver {
+	constructor(chain_links) {
+		super();
+		Object.assign(this, { chain_links });
+	}
+
+	resolve_handler(item) {
+		const { chain_links } = this;
+		for (const link of chain_links) {
+			const handler = link.resolve_handler(item);
+			if (handler) {
+				return handler;
+			}
+		}
+	}
+}
+
+
+class Mapping_Resolver {
+	constructor(rules=new Map(), key_function=null) {
+		Object.assign(this, { rules, key_function });
+	}
+
+	resolve_handler(item) {
+		const { key_function, rules } = this;
+		const key = key_function ? key_function(item) : item;
+		return rules.get(key);
+	}
+
+}
+
+
+
+const vr = new Mapping_Resolver();
+const tr = new Mapping_Resolver(new Map(), item => typeof item);
+
+const cr = new Chained_Resolver([vr, tr]);
+
+
+vr.rules.set('HELLO', () => 'WORLD');
+tr.rules.set('string', () => 'World');
+
+console.log(cr.resolve('HELLO'));
+console.log(cr.resolve('hello'));