implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/trait/equality.js

@@ -0,0 +1,26 @@
+export const EqualityTraitSymbol = Symbol('Equality')
+
+/**
+ * @typedef {{ [EqualityTraitSymbol]:(other:EqualityTrait)=>boolean }} EqualityTrait
+ */
+
+/**
+ *
+ * Utility function to compare any two objects.
+ *
+ * Note that it is expected that the first parameter is more specific than the latter one.
+ *
+ * @example js
+ *     class X { [traits.EqualityTraitSymbol] (other) { return other === this }  }
+ *     class X2 { [traits.EqualityTraitSymbol] (other) { return other === this }, x2 () { return 2 }  }
+ *     // this is fine
+ *     traits.equals(new X2(), new X())
+ *     // this is not, because the left type is less specific than the right one
+ *     traits.equals(new X(), new X2())
+ *
+ * @template {EqualityTrait} T
+ * @param {NoInfer<T>} a
+ * @param {T} b
+ * @return {boolean}
+ */
+export const equals = (a, b) => a === b || !!a?.[EqualityTraitSymbol]?.(b) || false