union Any {
  Start,
  StartRes,
  CodeFetch,
  CodeFetchRes,
  CodeCache,
  SetTimeout,
  Exit,
  Environ,
  EnvironRes,
  FetchReq,
  FetchRes,
  MakeTempDir,
  MakeTempDirRes,
  Mkdir,
  Remove,
  ReadFile,
  ReadFileRes,
  ReadDir,
  ReadDirRes,
  WriteFile,
  CopyFile,
  Rename,
  Readlink,
  ReadlinkRes,
  Symlink,
  Stat,
  StatRes,
  SetEnv,
  Truncate,
  Open,
  OpenRes,
  Read,
  ReadRes,
  Write,
  WriteRes,
  Close,
  Shutdown,
  Listen,
  ListenRes,
  Accept,
  Dial,
  NewConn,
  Chdir,
  Cwd,
  CwdRes,
  Metrics,
  MetricsRes,
}

enum ErrorKind: byte {
  NoError = 0,

  // io errors

  NotFound,
  PermissionDenied,
  ConnectionRefused,
  ConnectionReset,
  ConnectionAborted,
  NotConnected,
  AddrInUse,
  AddrNotAvailable,
  BrokenPipe,
  AlreadyExists,
  WouldBlock,
  InvalidInput,
  InvalidData,
  TimedOut,
  Interrupted,
  WriteZero,
  Other,
  UnexpectedEof,

  BadResource,

  // url errors

  EmptyHost,
  IdnaError,
  InvalidPort,
  InvalidIpv4Address,
  InvalidIpv6Address,
  InvalidDomainCharacter,
  RelativeUrlWithoutBase,
  RelativeUrlWithCannotBeABaseBase,
  SetHostOnCannotBeABaseUrl,
  Overflow,

  // hyper errors

  HttpUser,
  HttpClosed,
  HttpCanceled,
  HttpParse,
  HttpOther,
}

table Cwd {}

table CwdRes {
  cwd: string;
}

table Base {
  cmd_id: uint32;
  sync: bool = true; // TODO(ry) Change default to false.
  error_kind: ErrorKind = NoError;
  error: string;
  inner: Any;
}

table Start {
  unused: int8;
}

table StartRes {
  cwd: string;
  argv: [string];
  debug_flag: bool;
  deps_flag: bool;
  recompile_flag: bool;
  types_flag: bool;
}

table CodeFetch {
  module_specifier: string;
  containing_file: string;
}

table CodeFetchRes {
  // If it's a non-http module, moduleName and filename will be the same.
  // For http modules, moduleName is its resolved http URL, and filename
  // is the location of the locally downloaded source code.
  module_name: string;
  filename: string;
  source_code: string;
  output_code: string; // Non-empty only if cached.
}

table CodeCache {
  filename: string;
  source_code: string;
  output_code: string;
}

table Chdir {
  directory: string;
}

table SetTimeout {
  timeout: double;
}

table Exit {
  code: int;
}

table Environ {}

table SetEnv {
  key: string;
  value: string;
}

table EnvironRes {
  map: [EnvPair];
}

table EnvPair {
  key: string;
  value: string;
}

table FetchReq {
  id: uint;
  url: string;
  // header_line: [string];
}

table FetchRes {
  id: uint;
  status: int;
  header_key: [string];
  header_value: [string];
  body: [ubyte];
}

table MakeTempDir {
  dir: string;
  prefix: string;
  suffix: string;
}

table MakeTempDirRes {
  path: string;
}

table Mkdir {
  path: string;
  mode: uint;
  // mode specified by https://godoc.org/os#FileMode
}

table Remove {
  path: string;
  recursive: bool;
}

table ReadFile {
  filename: string;
}

table ReadFileRes {
  data: [ubyte];
}

table ReadDir {
  path: string;
}

table ReadDirRes {
  entries: [StatRes];
}

table WriteFile {
  filename: string;
  data: [ubyte];
  perm: uint;
  // perm specified by https://godoc.org/os#FileMode
}

table CopyFile {
  from: string;
  to: string;
}

table Rename {
  oldpath: string;
  newpath: string;
}

table Readlink {
  name: string;
}

table ReadlinkRes {
  path: string;
}

table Symlink {
  oldname: string;
  newname: string;
}

table Stat {
  filename: string;
  lstat: bool;
}

table StatRes {
  is_file: bool;
  is_symlink: bool;
  len: ulong;
  modified:ulong;
  accessed:ulong;
  created:ulong;
  mode: uint;
  has_mode: bool; // false on windows
  name: string;
  path: string;
}

table Truncate {
  name: string;
  len: uint;
}

table Open {
  filename: string;
  perm: uint;
}

table OpenRes {
  rid: int;
}

table Read {
  rid: int;
  // (ptr, len) is passed as second parameter to libdeno.send().
}

table ReadRes {
  nread: uint;
  eof: bool;
}

table Write {
  rid: int;
}

table WriteRes {
  nbyte: uint;
}

table Close {
  rid: int;
}

table Shutdown {
  rid: int;
  how: uint;
}

table Listen {
  network: string;
  address: string;
}

table ListenRes {
  rid: int;
}

table Accept {
  rid: int;
}

table Dial {
  network: string;
  address: string;
}

// Response to Accept and Dial.
table NewConn {
  rid: int;
  remote_addr: string;
  local_addr: string;
}

table Metrics {}

table MetricsRes {
  ops_dispatched: uint64;
  ops_completed: uint64;
  bytes_sent_control: uint64;
  bytes_sent_data: uint64;
  bytes_received: uint64;
}

root_type Base;