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export type Path = string[];export type Node<T> = File<T> | Folder<T>;
interface NodeBase<TType> {  type: TType;}export interface File<T> extends NodeBase<"file"> {  value: T;}export interface Folder<T> extends NodeBase<"folder"> {  value?: T;  children: { [key: string]: Node<T> };}
export const empty: Folder<any> = Object.freeze({  type: "folder",  children: Object.freeze({}),});
export function file<T>(value: T): File<T> {  return { type: "file", value };}
export function textToPath(text: string, sep: string = "/"): Path {  return text.split(sep).filter(Boolean);}
export function* walkFiles<T>(  node: Node<T>,  path: Path = [],): Generator<[Path, File<T>]> {  if (node.type === "file") {    yield [path, node];    return;  }  for (const [name, child] of Object.entries(node.children)) {    if (child.type === "file") yield [[...path, name], child];    if (child.type === "folder") yield* walkFiles(child, [...path, name]);  }}
export function* walkFolders<T>(  node: Node<T>,  path: Path = [],): Generator<[Path, Folder<T>]> {  if (node.type === "file") return;  yield [path, node];  for (const [name, child] of Object.entries(node.children)) {    if (child.type === "folder") yield* walkFolders(child, [...path, name]);  }}
export function has<T>(folder: Folder<T>, path: Path): boolean {  if (path.length < 1) return true;  const child = folder.children[path[0]];  if (path.length === 1) return !!child;  if (child.type === "file") return false;  return has(child, path.slice(1));}
export function get<T>(node: Node<T>, path: Path): Node<T> | undefined {  if (path.length < 1) return node;  if (node.type === "file") return;  const child = node.children[path[0]];  if (!child) return;  if (path.length === 1) return child;  return get(child, path.slice(1));}
export function set<T>(folder: Folder<T>, path: Path, value: T): Folder<T>;export function set<T>(node: Node<T>, path: Path, value: T): Node<T>;export function set<T>(node: Node<T>, path: Path, value: T): Node<T> {  if (path.length < 1) return { ...node, value };  const key = path[0];  const folder = node as Folder<T>;  const child = folder?.children?.[key];  return {    ...node,    type: "folder",    children: {      ...folder.children,      [key]: (!child && (path.length === 1))        ? file(value)        : set(child ?? empty, path.slice(1), value),    },  };}