@stdlib/streams
Version:
Streams.
290 lines (272 loc) • 7.82 kB
TypeScript
/*
* @license Apache-2.0
*
* Copyright (c) 2021 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// TypeScript Version: 4.1
/// <reference types="node"/>
import { Transform } from 'stream';
/**
* Interface defining stream options.
*/
interface Options {
/**
* Specifies whether a stream should operate in object mode (default: `false`).
*/
objectMode?: boolean;
/**
* Specifies how `Buffer` objects should be decoded to strings (default: `null`).
*/
encoding?: string | null;
/**
* Specifies the `Buffer` level for when `write()` starts returning `false`.
*/
highWaterMark?: number;
/**
* Separator used to join streamed data (default: `'\n'`).
*/
sep?: string;
/**
* Specifies whether the stream should remain open even if one side ends (default: `false`).
*/
allowHalfOpen?: boolean;
/**
* Specifies whether the readable side should be in object mode (default: `false`).
*/
readableObjectMode?: boolean;
}
/**
* Interface defining a stream constructor which is both "newable" and "callable".
*/
interface Constructor {
/**
* Join stream constructor.
*
* @param options - stream options
* @param options.sep - separator used to join streamed data (default: '\n')
* @param options.objectMode - specifies whether the stream should operate in object mode (default: false)
* @param options.encoding - specifies how `Buffer` objects should be decoded to `strings` (default: null)
* @param options.highWaterMark - specifies the `Buffer` level for when `write()` starts returning `false`
* @param options.allowHalfOpen - specifies whether the stream should remain open even if one side ends (default: false)
* @param options.readableObjectMode - specifies whether the readable side should be in object mode (default: false)
* @throws must provide valid options
* @returns join stream
*
* @example
* var inspectStream = require( './../../../../node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk );
* }
*
* var JoinStream = joinStream;
* var stream = new JoinStream();
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( '1' );
* stream.write( '2' );
* stream.write( '3' );
*
* stream.end();
*
* // prints: '1\n2\n3'
*/
new( options?: Options ): Transform; // newable
/**
* Join stream constructor.
*
* @param options - stream options
* @param options.sep - separator used to join streamed data (default: '\n')
* @param options.objectMode - specifies whether the stream should operate in object mode (default: false)
* @param options.encoding - specifies how `Buffer` objects should be decoded to `strings` (default: null)
* @param options.highWaterMark - specifies the `Buffer` level for when `write()` starts returning `false`
* @param options.allowHalfOpen - specifies whether the stream should remain open even if one side ends (default: false)
* @param options.readableObjectMode - specifies whether the readable side should be in object mode (default: false)
* @throws must provide valid options
* @returns join stream
*
* @example
* var inspectStream = require( './../../../../node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk );
* }
*
* var stream = joinStream();
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( '1' );
* stream.write( '2' );
* stream.write( '3' );
*
* stream.end();
*
* // prints: '1\n2\n3'
*/
( options?: Options ): Transform; // callable
/**
* Creates a reusable join stream factory.
*
* @param options - stream options
* @param options.sep - separator used to join streamed data (default: '\n')
* @param options.objectMode - specifies whether a stream should operate in object mode (default: false)
* @param options.encoding - specifies how `Buffer` objects should be decoded to `strings` (default: null)
* @param options.highWaterMark - specifies the `Buffer` level for when `write()` starts returning `false`
* @param options.allowHalfOpen - specifies whether the stream should remain open even if one side ends (default: false)
* @param options.readableObjectMode - specifies whether the readable side should be in object mode (default: false)
* @returns join stream factory
*
* @example
* var opts = {
* 'sep': '\t',
* 'objectMode': true,
* 'encoding': 'utf8',
* 'highWaterMark': 64
* };
*
* var factory = joinStream.factory( opts );
*
* // Create 10 identically configured streams...
* var streams = [];
* var i;
* for ( i = 0; i < 10; i++ ) {
* streams.push( factory() );
* }
*/
factory( options?: Options ): () => Transform;
/**
* Returns a join stream with `objectMode` set to `true`.
*
* @param options - stream options
* @param options.sep - separator used to join streamed data (default: '\n')
* @param options.encoding - specifies how `Buffer` objects should be decoded to `strings` (default: null)
* @param options.highWaterMark - specifies the `Buffer` level for when `write()` starts returning `false`
* @param options.allowHalfOpen - specifies whether the stream should remain open even if one side ends (default: false)
* @param options.readableObjectMode - specifies whether the readable side should be in object mode (default: false)
* @throws must provide valid options
* @returns join stream
*
* @example
* var inspectStream = require( './../../../../node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk.toString() );
* }
*
* var stream = joinStream.objectMode({
* 'sep': ','
* });
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( 'a' );
* stream.write( 'b' );
* stream.write( 'c' );
*
* stream.end();
*
* // prints: 'a,b,c'
*/
objectMode( options?: Options ): Transform;
}
/**
* Returns a join stream.
*
* @param options - stream options
* @throws must provide valid options
* @returns stream instance
*
* @example
* var inspectStream = require( '@stdlib/streams/node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk );
* }
*
* var JoinStream = joinStream;
* var stream = new JoinStream();
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( '1' );
* stream.write( '2' );
* stream.write( '3' );
*
* stream.end();
*
* // prints: '1\n2\n3'
*
* @example
* var inspectStream = require( '@stdlib/streams/node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk );
* }
*
* var stream = joinStream();
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( '1' );
* stream.write( '2' );
* stream.write( '3' );
*
* stream.end();
*
* // prints: '1\n2\n3';
*
* @example
* var opts = {
* 'sep': '\t',
* 'objectMode': true,
* 'encoding': 'utf8',
* 'highWaterMark': 64
* };
*
* var factory = joinStream.factory( opts );
*
* // Create 10 identically configured streams...
* var streams = [];
* var i;
* for ( i = 0; i < 10; i++ ) {
* streams.push( factory() );
* }
*
* @example
* var inspectStream = require( '@stdlib/streams/node/inspect-sink' );
*
* function log( chunk ) {
* console.log( chunk.toString() );
* }
*
* var stream = joinStream.objectMode({
* 'sep': ','
* });
*
* stream.pipe( inspectStream( log ) );
*
* stream.write( 'a' );
* stream.write( 'b' );
* stream.write( 'c' );
*
* stream.end();
*
* // prints: 'a,b,c'
*/
declare var joinStream: Constructor;
// EXPORTS //
export = joinStream;