@stdlib/streams
Version:
Streams.
100 lines (89 loc) • 2.97 kB
JavaScript
/**
* @license Apache-2.0
*
* Copyright (c) 2018 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.
*/
;
// MODULES //
var isObject = require( '@stdlib/assert/is-plain-object' );
var format = require( '@stdlib/string/format' );
var assign = require( '@stdlib/object/assign' );
var ArrayStream = require( './main.js' );
// MAIN //
/**
* Returns a function for creating readable streams from array-like objects.
*
* @param {Options} [options] - stream options
* @param {boolean} [options.objectMode=false] - specifies whether a stream should operate in object mode
* @param {(string|null)} [options.encoding=null] - specifies how `Buffer` objects should be decoded to `strings`
* @param {NonNegativeNumber} [options.highWaterMark] - specifies the maximum number of bytes to store in an internal buffer before pausing streaming
* @param {string} [options.sep='\n'] - separator used to join streamed data
* @param {Function} [options.serialize] - custom serialization function
* @param {integer} [options.dir=1] - iteration direction
* @throws {TypeError} options argument must be an object
* @returns {Function} stream factory
*
* @example
* var Float64Array = require( '@stdlib/array/float64' );
* var randu = require( '@stdlib/random/base/randu' );
*
* var arr = new Float64Array( 10 );
* var i;
* for ( i = 0; i < arr.length; i++ ) {
* arr[ i ] = randu();
* }
*
* var opts = {
* 'sep': ',',
* 'objectMode': false,
* 'encoding': 'utf8',
* 'highWaterMark': 64
* };
*
* var createStream = factory( opts );
*
* // Create 10 identically configured streams...
* var streams = [];
* for ( i = 0; i < 10; i++ ) {
* streams.push( createStream( arr ) );
* }
*/
function factory( options ) {
var opts;
if ( arguments.length ) {
if ( !isObject( options ) ) {
throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
}
opts = assign( {}, options );
} else {
opts = {};
}
return createStream;
/**
* Returns a readable stream from an array-like object.
*
* @private
* @param {Collection} src - source array-like object
* @throws {TypeError} must provide an array-like object
* @throws {TypeError} options argument must be an object
* @throws {TypeError} must provide valid options
* @returns {ArrayStream} Stream instance
*/
function createStream( src ) {
return new ArrayStream( src, opts );
}
}
// EXPORTS //
module.exports = factory;