mongoist/index.js.flow

Mongodb driver inspired by mongojs built with async/await in mind

/**
 * @flow strict
 *
 * Type definitions for mongoist in Flow.
 */

type ReadPreference =
  | 'primary'
  | 'primaryPreferred'
  | 'secondary'
  | 'secondaryPreferred'
  | 'nearest'
  | null;

type WriteConcern = {|
  +w?: number | 'majority' | string | null,
  +wtimeout?: number | null,
  +j?: boolean,
|};

declare export class Timestamp {
  static MAX_VALUE: Timestamp;
  static MIN_VALUE: Timestamp;
  static NEG_ONE: Timestamp;
  static ONE: Timestamp;
  static ZERO: Timestamp;

  static fromBits(low: number, high: number): Timestamp;
  static fromInt(value: number): Timestamp;
  static fromNumber(value: number): Timestamp;
  static fromString(value: string, radix?: number): Timestamp;

  constructor(low: number, high: number): Timestamp;

  add(Timestamp): Timestamp;
  and(Timestamp): Timestamp;
  compare(Timestamp): number;
  div(Timestamp): Timestamp;
  equals(Timestamp): boolean;
  getHighBits(): number;
  getLowBits(): number;
  getLowBitsUnsigned(): number;
  getNumBitsAbs(): number;
  greaterThan(Timestamp): boolean;
  greaterThanOrEqual(Timestamp): boolean;
  isNegative(): boolean;
  isOdd(): boolean;
  isZero(): boolean;
  lessThan(Timestamp): boolean;
  lessThanOrEqual(Timestamp): boolean;
  modulo(Timestamp): Timestamp;
  multiply(Timestamp): Timestamp;
  negate(): Timestamp;
  not(): Timestamp;
  notEquals(Timestamp): boolean;
  or(Timestamp): Timestamp;
  shiftLeft(numBits: number): Timestamp;
  shiftRight(numBits: number): Timestamp;
  shiftRightUnsigned(numBits: number): Timestamp;
  subtract(Timestamp): Timestamp;
  toInt(): number;
  toJSON(): string;
  toNumber(): number;
  toString(radix?: number): string;
  xor(Timestamp): Timestamp;
}

type TransactionOptions = {|
  +readConcern?: mixed,
  +writeConcern?: WriteConcern,
  +readPreference?: ReadPreference,
|};

// Not actually exported by mongoist, but used structurally in parameter
// types.
interface ClientSession {
  id: mixed;

  abortTransaction(): Promise<mixed>;
  abortTransaction(callback: (Error | null, reply?: null) => mixed): void;
  advanceOperationTime(Timestamp): void;
  commitTransaction(): Promise<mixed>;
  commitTransaction(callback: (Error | null, reply?: null) => mixed): void;
  endSession(): void;
  endSession(callback: (Error | null, reply?: null) => mixed): void;
  endSession(
    options: ?{ [string]: mixed, ... },
    callback: (Error | null, reply?: null) => mixed
  ): void;
  equals(ClientSession): boolean;
  incrementTransactionNumber(): void;
  inTransaction(): boolean;
  startTransaction(options?: TransactionOptions): void;
  withTransaction(
    fn: (session: ClientSession) => Promise<mixed>,
    options?: TransactionOptions
  ): Promise<null | void>;
}

type BulkExecuteResult = {|
  ok: 1,
  writeErrors: mixed[],
  writeConcernErrors: mixed[],
  nInserted: number,
  nUpserted: number,
  nMatched: number,
  nModified: number,
  nRemoved: number,
  upserted: mixed[],
|};

type BulkJSONValue = {|
  nInsertOps: number,
  nUpdateOps: number,
  nRemoveOps: number,
  nBatches: number,
|};

interface FindSyntax {
  upsert(): FindSyntax;
  remove(): void;
  removeOne(): void;
  update(update: mixed): void;
  updateOne(update: mixed): void;
  replaceOne(update: mixed): void;
}

export interface Bulk {
  ensureCommand(cmdName: string, bulkCollection: mixed): mixed;
  find(selector: ReadOnlyQuery): FindSyntax;
  insert(doc: { +[string]: mixed, ... }): void;
  execute(): Promise<BulkExecuteResult>;
  pushCurrentCmd(): void;
  tojson(): BulkJSONValue;
}

type BulkOptions = {|
  ...WriteConcern,
  +ignoreUndefined?: boolean,
  +session?: ClientSession,
|};

export type ConnectionOptions = $ReadOnly<{|
  poolSize?: number,
  ssl?: boolean,
  sslValidate?: boolean,
  sslCA?: (Buffer | string)[],
  sslCert?: Buffer | string,
  sslKey?: Buffer | string,
  sslPass?: Buffer | string,
  sslCRL?: Buffer,
  autoReconnect?: boolean,
  noDelay?: boolean,
  keepAlive?: number,
  keepAliveInitialDelay?: number,
  connectTimeoutMS?: number,
  family?: 4 | 6 | null,
  socketTimeoutMS?: number,
  reconnectTries?: number,
  reconnectInterval?: number,
  ha?: boolean,
  haInterval?: number,
  replicaSet?: string | null,
  secondaryAcceptableLatencyMS?: number,
  acceptableLatencyMS?: number,
  connectWithNoPrimary?: boolean,
  authSource?: string | null,
  ...WriteConcern,
  forceServerObjectId?: boolean,
  serializeFunctions?: boolean,
  ignoreUndefined?: boolean,
  raw?: boolean,
  bufferMaxEntries?: number,
  promoteValues?: boolean,
  promoteBuffers?: boolean,
  promoteLongs?: boolean,
  domainsEnabled?: boolean,
  bufferMaxEntries?: number,
  readPreference?: ReadPreference,
  // Some sort of vaguely-defined generator for primary keys.
  pkFactory?: mixed,
  promiseLibrary?: mixed | null,
  readConcern?: {|
    level?: 'local' | 'available' | 'majority' | 'linearizable' | 'snapshot',
  |},
  maxStalenessSeconds?: number | null,
  appname?: string | null,
  loggerLevel?: string | null,
  // TODO: is this right?
  logger?: typeof console | null,
  checkServerIdentity?: boolean | mixed,
  validateOptions?: mixed,
  auth?: {|
    user?: string,
    password?: string,
  |},
  authMechanism?: 'MDEFAULT' | 'GSSAPI' | 'PLAIN' | 'MONGODB-X509' | 'SCRAM-SHA-1',
  compression?: mixed,
  fsync?: boolean,
  readPreferenceTags?: mixed[],
  numberOfRetries?: number,
  auto_reconnect?: boolean,
  minSize?: number,
|}>;

declare opaque type Connection;
declare opaque type InternalCollection;
declare opaque type InternalCursor;

export type Query = {
  [string]: mixed,
  ...,
};

// This type is the same as the Query type, and is just used to avoid type errors when the type
// passed in to the update field/parameter isn't fully compatible when mutated at runtime.
type ReadOnlyQuery = $ReadOnly<Query>;

type CollationParam = $ReadOnly<{|
  locale: string,
  caseLevel?: boolean,
  caseFirst?: 'upper' | 'lower' | 'off',
  strength?: 1 | 2 | 3 | 4 | 5,
  numericOrdering?: boolean,
  alternate?: 'non-ignorable' | 'shifted',
  maxVariable?: 'punct' | 'space',
  backwards?: boolean,
  normalization?: boolean,
|}>;

type TailableOptions =
  | {|
      +tailable?: false,
    |}
  | {|
      +tailable: true,
      +awaitData?: false,
    |}
  | {|
      +tailable: true,
      +awaitData: true,
      +maxAwaitTimeMS?: number,
    |};

type QueryOptions = $ReadOnly<{|
  limit?: number,
  sort?: mixed,
  projection?: Projection,
  skip?: number,
  hint?: mixed,
  explain?: boolean,
  snapshot?: boolean,
  timeout?: boolean,
  ...TailableOptions,
  batchSize?: number,
  returnKey?: boolean,
  min?: number,
  max?: number,
  showDiskLoc?: boolean,
  comment?: string,
  raw?: boolean,
  promoteLongs?: boolean,
  promoteValues?: boolean,
  promoteBuffers?: boolean,
  readPreference?: ReadPreference,
  partial?: boolean,
  maxTimeMS?: number,
  noCursorTimeout?: boolean,
  collation?: CollationParam,
  session?: ClientSession,
|}>;

type FindAndModifyParams = $ReadOnly<{|
  query: ReadOnlyQuery,
  sort?: mixed,
  remove?: boolean,
  update?: ReadOnlyUpdate | AggregationUpdate,
  new?: boolean,
  fields?: Projection,
  upsert?: boolean,
  bypassDocumentValidation?: boolean,
  writeConcern?: WriteConcern,
  maxTimeMS?: number,
  findAndModify?: string,
  collation?: CollationParam,
  // mutually exclusive with update: mixed[]
  arrayFilters?: mixed[],
|}>;

type BaseUpsertOptions = $ReadOnly<{|
  ...WriteConcern,
  bypassDocumentValidation?: boolean,
  checkKeys?: boolean,
  ignoreUndefined?: boolean,
  serializeFunctions?: boolean,
  // TODO: merge with WriteConcern
  session?: ClientSession,
|}>;

type UpdateOptions = $ReadOnly<{|
  ...BaseUpsertOptions,
  arrayFilters?: mixed[],
  collation?: CollationParam,
  hint?: mixed,
  upsert?: boolean,
  multi?: boolean,
|}>;

type ReplaceOptions = {|
  ...BaseUpsertOptions,
  +collation?: CollationParam,
  +hint?: mixed,
|};

type InsertOptions = {|
  ...BaseUpsertOptions,
  +forceServerObjectId?: boolean,
|};

type RemoveOptions =
  | boolean
  | $ReadOnly<{|
      ...WriteConcern,
      justOne: boolean,
      collation?: CollationParam,
      checkKeys?: boolean,
      serializeFunctions?: boolean,
      ignoreUndefined?: boolean,
      session?: ClientSession,
    |}>;

type RenameOptions = {|
  +dropTarget?: boolean,
  +session?: ClientSession,
|};

type UpdateOrReplaceResult = {|
  ok: number,
  n: number,
  nModified: number,
|};

// Note that this type differs slightly from the one provided by the MongoDB native driver.
type DeleteResult = {|
  // ok === 1 on success
  ok: number,
  n: number,
  deletedCount: number,
|};

type BaseRunCommandOptions = {|
  +readPreference?: ReadPreference,
|};

type RunCommandOptions = {|
  +[string]: 1,
  ...BaseRunCommandOptions,
|};

interface MongoJSDuck {
  _getConnection(any): mixed;
}

type MapParam = string | (() => void);
type ReduceParam<R> = string | ((key: mixed, values: mixed[]) => R);

// http://mongodb.github.io/node-mongodb-native/3.3/api/Collection.html#mapReduce
type MapReduceOptions<R> = $ReadOnly<{|
  readPreference?: ReadPreference,
  out: {| inline: 1 |} | {| ['replace' | 'merge' | 'reduce']: 'string' |},
  query?: ReadOnlyQuery,
  sort?: mixed,
  limit?: number,
  keeptemp?: boolean,
  finalize?: string | ((key: mixed, value: R) => mixed),
  scope?: mixed,
  jsMode?: boolean,
  verbose?: boolean,
  bypassDocumentValidation?: boolean,
  session?: ClientSession,
|}>;

type IndexType = '2d' | '2dsphere' | 'geoHaystack' | 'text' | 'hashed';
type IndexFieldSpec = -1 | 1 | IndexType;
type BaseIndex = string | { [string]: IndexFieldSpec };
type Index = BaseIndex | (BaseIndex | [string, IndexFieldSpec])[];

type IndexOptions = $ReadOnly<{|
  ...WriteConcern,
  unique?: boolean,
  sparse?: boolean,
  background?: boolean,
  dropDups?: boolean,
  min?: number,
  max?: number,
  v?: number,
  expireAfterSeconds?: number,
  name?: string,
  partialFilterExpression?: { [string]: mixed, ... },
  collation?: CollationParam,
  session?: ClientSession,
|}>;

type AggregationPipeline = $ReadOnlyArray<
  | {| +$addFields: mixed |}
  | {| +$bucket: mixed |}
  | {| +$bucketAuto: mixed |}
  | {| +$collStats: mixed |}
  | {| +$count: mixed |}
  | {| +$facet: mixed |}
  | {| +$geoNear: mixed |}
  | {| +$graphLookup: mixed |}
  | {| +$group: mixed |}
  | {| +$indexStats: mixed |}
  | {| +$limit: mixed |}
  | {| +$listSessions: mixed |}
  | {| +$lookup: mixed |}
  | {| +$match: mixed |}
  | {| +$merge: mixed |}
  | {| +$out: mixed |}
  | {| +$planCacheStats: mixed |}
  | {| +$project: mixed |}
  | {| +$redact: mixed |}
  | {| +$replaceRoot: mixed |}
  | {| +$replaceWith: mixed |}
  | {| +$sample: mixed |}
  | {| +$set: mixed |}
  | {| +$skip: mixed |}
  | {| +$sort: mixed |}
  | {| +$sortByCount: mixed |}
  | {| +$unset: mixed |}
  | {| +$unwind: mixed |}
>;

type AggregationOptions = $ReadOnly<{|
  readPreference?: ReadPreference,
  batchSize?: number,
  cursor?: mixed,
  explain?: boolean,
  allowDiskUse?: boolean,
  maxTimeMS?: number,
  maxAwaitTimeMS?: number,
  bypassDocumentValidation?: boolean,
  raw?: boolean,
  promoteLongs?: boolean,
  promoteValues?: boolean,
  promoteBuffers?: boolean,
  collation?: CollationParam,
  comment?: string,
  hint?: string | { [string]: mixed, ... },
  session?: ClientSession,
|}>;

// https://github.com/facebook/flow/issues/2753
declare export class Cursor<Doc> extends stream$Readable {
  constructor(cursorFactory: () => Promise<InternalCursor>): Cursor<Doc>;

  addCursorFlag(flag: string, value: mixed): this;
  batchSize(value: number): this;
  close(): Promise<mixed>;
  collation(value: CollationParam): this;
  count(): Promise<number>;
  destroy(): this;
  explain(): Promise<mixed>;
  forEach(fn: (doc: Doc) => mixed): Promise<void>;
  getCursor(): Promise<InternalCursor>;
  hasNext(): Promise<boolean>;
  hint(index: Index | { $natural: 1 | -1 }): this;
  limit(limit: number): this;
  map<V>(fn: (doc: Doc) => V): Promise<V[]>;
  max(indexBounds: { [string]: mixed }): this;
  maxTimeMS(ms: number): this;
  min(indexBounds: { [string]: mixed }): this;
  next(): Promise<Doc | null>;
  rewind(): Promise<mixed>;
  size(): Promise<number>;
  skip(offset: number): this;
  snapshot(...args: mixed[]): this;
  sort(order: {| +$natural: 1 |} | { +[string]: -1 | 1 | {| +$meta: 'textScore' |}, ... }): this;
  toArray(): Promise<Doc[]>;

  @@asyncIterator(): AsyncIterator<Doc>;
}

type Expression = mixed;

type ConstrainedProjection<V> = {
  [string]:
    | V
    | {| $meta: 'textScore' |}
    | {| $slice: number | [number, number] |}
    | {| $elemMatch: Expression |},
  ...,
};

export type Projection = {
  ...ConstrainedProjection<0 | false> | ConstrainedProjection<1 | true>,
  _id?: false | 0 | true | 1,
  ...
};

type AggregationUpdate = $ReadOnlyArray<
  | {|
      +['$addFields' | '$set' | '$replaceWith']: { [string]: Expression, ... },
    |}
  | {|
      +$project:
        | { +[string]: 0 | false, +_id?: Expression | 0 | false | 1 | true, ... }
        | { +[string]: Expression | 1 | true, +_id?: Expression | 0 | false | 1 | true, ... },
    |}
  | {| +$unset: string | string[] |}
  | {| +$replaceRoot: { +newRoot: { +[string]: Expression, ... } } |}
>;

export type Update = {|
  $addToSet?: { [string]: mixed, ... },
  $bit?: { ['and' | 'or' | 'xor']: number },
  $currentDate?: { [string]: true | { $type: 'timestamp' | 'date' } },
  $inc?: { [string]: number, ... },
  $max?: { [string]: mixed, ... },
  $min?: { [string]: mixed, ... },
  $pop?: { [string]: -1 | 1, ... },
  $pull?: { [string]: mixed, ... },
  $pullAll?: { [string]: mixed, ... },
  $push?: { [string]: mixed, ... },
  $rename?: { [string]: mixed, ... },
  $set?: { [string]: mixed, ... },
  // TODO: forbid this option if upsert is not true.
  $setOnInsert?: { [string]: mixed, ... },
  $unset?: { [string]: mixed, ... },
|};

// This type is the same as the Update type, and is just used to avoid type errors when the type
// passed in to the update field/parameter isn't fully compatible when mutated at runtime.
type ReadOnlyUpdate = $ReadOnly<{|
  $addToSet?: { +[string]: mixed, ... },
  $bit?: { +['and' | 'or' | 'xor']: number },
  $currentDate?: { +[string]: true | { +$type: 'timestamp' | 'date' } },
  $inc?: { +[string]: number, ... },
  $max?: { +[string]: mixed, ... },
  $min?: { +[string]: mixed, ... },
  $pop?: { +[string]: -1 | 1, ... },
  $pull?: { +[string]: mixed, ... },
  $pullAll?: { +[string]: mixed, ... },
  $push?: { +[string]: mixed, ... },
  $rename?: { +[string]: mixed, ... },
  $set?: { +[string]: mixed, ... },
  // TODO: forbid this option if upsert is not true.
  $setOnInsert?: { +[string]: mixed, ... },
  $unset?: { +[string]: mixed, ... },
|}>;

type AddObjectIDField = <Doc>(Doc) => { _id: ObjectID, ...Doc };

declare export class Collection {
  constructor(db: Database_, name: string): Collection;

  name: string;

  connect(): Promise<InternalCollection>;
  find<Doc>(query?: ReadOnlyQuery, projection?: Projection, options?: QueryOptions): Promise<Doc[]>;
  findAsCursor<Doc>(
    query?: ReadOnlyQuery,
    projection?: Projection,
    options?: QueryOptions
  ): Cursor<Doc>;
  findOne<Doc>(
    query?: ReadOnlyQuery,
    projection?: Projection,
    options?: QueryOptions
  ): Promise<Doc | null>;
  findAndModify<Doc>(options: { ...FindAndModifyParams, upsert: true }): Promise<Doc>;
  findAndModify<Doc>(options: FindAndModifyParams): Promise<Doc | null>;
  count(query: ReadOnlyQuery): Promise<number>;
  distinct<FieldType>(field: string, query: ReadOnlyQuery): Promise<FieldType[]>;
  insert: typeof Collection.prototype.insertOne & typeof Collection.prototype.insertMany;
  insertOne<Doc>(doc: Doc, options?: InsertOptions): Promise<$Call<AddObjectIDField, Doc>>;
  insertMany<Docs>(docs: Docs, options?: InsertOptions): Promise<$TupleMap<Docs, AddObjectIDField>>;
  // TODO: improve safety by restricting update type.
  update(
    query: ReadOnlyQuery,
    update: ReadOnlyUpdate | AggregationUpdate,
    options?: UpdateOptions
  ): Promise<UpdateOrReplaceResult>;
  replaceOne(
    query: ReadOnlyQuery,
    replacement: mixed,
    options?: ReplaceOptions
  ): Promise<UpdateOrReplaceResult>;
  // TODO: restrict to some form of ArbitraryBSON.
  save<Doc>(doc: Doc, options?: BaseUpsertOptions): Promise<{| _id: ObjectID, ...Doc |}>;
  remove(query: ReadOnlyQuery, options?: RemoveOptions): Promise<DeleteResult>;
  rename(name: string, options?: RenameOptions): Promise<InternalCollection>;
  // TODO: refine this based on the provided command name.
  runCommand(command: string, options?: BaseRunCommandOptions): Promise<mixed>;
  drop(): Promise<mixed>;
  stats(): Promise<mixed>;
  mapReduce<R>(map: MapParam, reduce: ReduceParam<R>, options: MapReduceOptions<R>): Promise<mixed>;
  dropIndexes(): Promise<mixed>;
  dropIndex(index: string): Promise<mixed>;
  createIndex(index: Index, options?: IndexOptions): Promise<mixed>;
  ensureIndex: typeof Collection.prototype.createIndex;
  getIndexes(): Promise<mixed>;
  reIndex(): Promise<mixed>;
  isCapped(): Promise<boolean>;
  aggregate<Doc>(pipeline: AggregationPipeline, options?: AggregationOptions): Promise<Doc[]>;
  aggregateAsCursor<Doc>(pipeline: AggregationPipeline, options?: AggregationOptions): Cursor<Doc>;
  initializeOrderedBulkOp(options?: BulkOptions): Bulk;
  initializeUnorderedBulkOp(options?: BulkOptions): Bulk;
}

type MaybePromise<T> = T | Promise<T>;

type CollectionOptions = $ReadOnly<{|
  capped?: boolean,
  size?: number,
  max?: number,
  storageEngine?: { +[string]: mixed, ... },
  validator?: { +[string]: mixed, ... },
  validationLevel?: 'off' | 'strict' | 'moderate',
  validationAction?: 'error' | 'warn',
  indexOptionDefaults?: { +[string]: mixed, ... },
  collation?: CollationParam,
  writeConcern?: { +[string]: mixed, ... },
|}>;

type Stats = {|
  db: string,
  collections: number,
  objects: number,
  avgObjectSize: number,
  dataSize: number,
  storageSize: number,
  numExtents: number,
  indexes: number,
  indexSize: number,
  scaleFactor?: number,
  fsUsedSize?: number,
  fsTotalSize?: number,
  ok?: number,
|};

// https://github.com/facebook/flow/issues/2753
declare class Database_ extends events$EventEmitter {
  constructor(connectionString: MaybePromise<string>, options?: ConnectionOptions): Database_;
  constructor(database: MaybePromise<Database_ | DatabaseWithProxy | MongoJSDuck>): Database_;

  connect(): Promise<Connection>;
  close(force?: boolean): Promise<void>;
  dropDatabase(): Promise<mixed>;

  collection(name: string): Collection;
  createCollection(name: string, options?: CollectionOptions): Promise<mixed>;
  getCollectionInfos(): Promise<mixed[]>;
  getCollectionNames(): Promise<string[]>;
  listCollections(): Promise<mixed[]>;

  adminCommand(command: string | RunCommandOptions): Promise<mixed>;
  runCommand(command: string | RunCommandOptions): Promise<mixed>;

  createUser(user: mixed): Promise<mixed>;
  dropAllUsers(): Promise<mixed>;
  dropUser(username: string): Promise<mixed>;

  getLastError(): Promise<string | null>;
  getLastErrorObj(): Promise<{ [string]: mixed, ... }>;
  stats(scale?: mixed): Promise<Stats>;
}

type DatabaseWithProxy = Database_ & { [string]: Collection, ... };

// declare function connect(
//   connectionString: string,
//   options?: ConnectionOptions
// ): DatabaseWithProxy;

// declare type Connect = (connectionString: Database | MongoJSDuck) => DatabaseWithProxy;
// declare function connect(connectionString: Database_ | MongoJSDuck): DatabaseWithProxy;

declare export class ObjectID {
  constructor(value?: ?(string | number | ObjectID)): ObjectID;

  generationTime: number;

  static createFromHexString(hexString: string): ObjectID;
  static createFromTime(time: number): ObjectID;
  static isValid(id: ObjectID | Buffer | number): true;
  static isValid(id: string | mixed): boolean;

  equals(ObjectID): boolean;
  generate(time?: number): Buffer;
  getTimestamp(): Date;
  toHexString(): string;
}

type ConnectFn = {|
  (connectionParam: MaybePromise<string>, options?: ConnectionOptions): DatabaseWithProxy,
  (connectionParam: MaybePromise<Database_ | DatabaseWithProxy | MongoJSDuck>): DatabaseWithProxy,

  default: ConnectFn,

  Database: DatabaseWithProxy,
  Collection: typeof Collection,
  Cursor: typeof Cursor,
  Bulk: Bulk,
  ObjectId: typeof ObjectID,
  ObjectID: typeof ObjectID,

  Binary: mixed,
  Code: mixed,
  DBRef: mixed,
  Double: mixed,
  Long: mixed,
  NumberLong: mixed,
  MinKey: mixed,
  MaxKey: mixed,
  Symbol: mixed,
  Timestamp: typeof Timestamp,
|};

declare export default ConnectFn;

export const ObjectId = ObjectID;
export type Database = DatabaseWithProxy;

export type Binary = mixed;
export type Code = mixed;
export type DBRef = mixed;
export type Double = mixed;
export type Long = mixed;
export type NumberLong = mixed;
export type MinKey = mixed;
export type MaxKey = mixed;
export type Symbol = mixed;