+export const getNodeChildrenIds = (id: string) => <T>(tree: Tree<T>): string[] =>
+ getNodeDescendantsIds(id, 0)(tree);
+
+export const mapIdsToNodes = (ids: string[]) => <T>(tree: Tree<T>) =>
+ ids.map(id => getNode(id)(tree)).filter((node): node is TreeNode<T> => node !== undefined);
+
+export const activateNode = (id: string) => <T>(tree: Tree<T>) =>
+ mapTree((node: TreeNode<T>) => node.id === id ? { ...node, active: true } : { ...node, active: false })(tree);
+
+export const deactivateNode = <T>(tree: Tree<T>) =>
+ mapTree((node: TreeNode<T>) => node.active ? { ...node, active: false } : node)(tree);
+
+export const expandNode = (...ids: string[]) => <T>(tree: Tree<T>) =>
+ mapTree((node: TreeNode<T>) => ids.some(id => id === node.id) ? { ...node, expanded: true } : node)(tree);
+
+export const expandNodeAncestors = (...ids: string[]) => <T>(tree: Tree<T>) => {
+ const ancestors = ids.reduce((acc, id): string[] => ([...acc, ...getNodeAncestorsIds(id)(tree)]), [] as string[]);
+ return mapTree((node: TreeNode<T>) => ancestors.some(id => id === node.id) ? { ...node, expanded: true } : node)(tree);
+}
+
+export const collapseNode = (...ids: string[]) => <T>(tree: Tree<T>) =>
+ mapTree((node: TreeNode<T>) => ids.some(id => id === node.id) ? { ...node, expanded: false } : node)(tree);
+
+export const toggleNodeCollapse = (...ids: string[]) => <T>(tree: Tree<T>) =>
+ mapTree((node: TreeNode<T>) => ids.some(id => id === node.id) ? { ...node, expanded: !node.expanded } : node)(tree);
+
+export const setNodeStatus = (id: string) => (status: TreeNodeStatus) => <T>(tree: Tree<T>) => {
+ const node = getNode(id)(tree);
+ return node
+ ? setNode({ ...node, status })(tree)
+ : tree;
+};
+
+export const toggleNodeSelection = (id: string, cascade: boolean) => <T>(tree: Tree<T>) => {
+ const node = getNode(id)(tree);
+
+ return node
+ ? cascade
+ ? pipe(
+ setNode({ ...node, selected: !node.selected }),
+ toggleAncestorsSelection(id),
+ toggleDescendantsSelection(id))(tree)
+ : setNode({ ...node, selected: !node.selected })(tree)
+ : tree;
+};
+
+export const selectNode = (id: string, cascade: boolean) => <T>(tree: Tree<T>) => {
+ const node = getNode(id)(tree);
+ return node && node.selected
+ ? tree
+ : toggleNodeSelection(id, cascade)(tree);
+};
+
+export const selectNodes = (id: string | string[], cascade: boolean) => <T>(tree: Tree<T>) => {
+ const ids = typeof id === 'string' ? [id] : id;
+ return ids.reduce((tree, id) => selectNode(id, cascade)(tree), tree);
+};
+export const deselectNode = (id: string, cascade: boolean) => <T>(tree: Tree<T>) => {
+ const node = getNode(id)(tree);
+ return node && node.selected
+ ? toggleNodeSelection(id, cascade)(tree)
+ : tree;
+};
+
+export const deselectNodes = (id: string | string[], cascade: boolean) => <T>(tree: Tree<T>) => {
+ const ids = typeof id === 'string' ? [id] : id;
+ return ids.reduce((tree, id) => deselectNode(id, cascade)(tree), tree);
+};