Function update

riot+compiler.js:23983–24012

(scope, parentScope)

      return this.update(scope, parentScope)
    },
    update(scope, parentScope) {
      const { placeholder, nodes, childrenMap } = this;
      const collection = scope === UNMOUNT_SCOPE ? null : this.evaluate(scope);
      const items = collection ? Array.from(collection) : [];

      // prepare the diffing
      const { newChildrenMap, batches, futureNodes } = createPatch(
        items,
        scope,
        parentScope,
        this,
      );

      // patch the DOM only if there are new nodes
      udomdiff(
        nodes,
        futureNodes,
        patch(Array.from(childrenMap.values()), parentScope),
        placeholder,
      );

      // trigger the mounts and the updates
      batches.forEach((fn) => fn());

      // update the children map
      this.childrenMap = newChildrenMap;
      this.nodes = futureNodes;

      return this
    },
    unmount(scope, parentScope) {
      this.update(UNMOUNT_SCOPE, parentScope);