implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/pair.js

@@ -0,0 +1,50 @@
+/**
+ * Working with value pairs.
+ *
+ * @module pair
+ */
+
+/**
+ * @template L,R
+ */
+export class Pair {
+  /**
+   * @param {L} left
+   * @param {R} right
+   */
+  constructor (left, right) {
+    this.left = left
+    this.right = right
+  }
+}
+
+/**
+ * @template L,R
+ * @param {L} left
+ * @param {R} right
+ * @return {Pair<L,R>}
+ */
+export const create = (left, right) => new Pair(left, right)
+
+/**
+ * @template L,R
+ * @param {R} right
+ * @param {L} left
+ * @return {Pair<L,R>}
+ */
+export const createReversed = (right, left) => new Pair(left, right)
+
+/**
+ * @template L,R
+ * @param {Array<Pair<L,R>>} arr
+ * @param {function(L, R):any} f
+ */
+export const forEach = (arr, f) => arr.forEach(p => f(p.left, p.right))
+
+/**
+ * @template L,R,X
+ * @param {Array<Pair<L,R>>} arr
+ * @param {function(L, R):X} f
+ * @return {Array<X>}
+ */
+export const map = (arr, f) => arr.map(p => f(p.left, p.right))