@stdlib/streams
Version:
Streams.
86 lines (76 loc) • 2.47 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 Stream = require( './main.js' );
// MAIN //
/**
* Returns an inspect stream with `objectMode` set to `true`.
*
* @param {Options} [options] - stream options
* @param {NonNegativeNumber} [options.highWaterMark] - specifies the `Buffer` level for when `write()` starts returning `false`
* @param {boolean} [options.allowHalfOpen=false] - specifies whether the stream should remain open even if one side ends
* @param {boolean} [options.readableObjectMode=false] - specifies whether the readable side should be in object mode
* @param {Callback} clbk - callback to invoke upon receiving data
* @throws {TypeError} options argument must be an object
* @throws {TypeError} must provide valid options
* @throws {TypeError} must provide a callback function
* @returns {InspectStream} inspect stream
*
* @example
* function log( chunk, idx ) {
* console.log( 'index: %d', idx );
* console.log( chunk );
* }
*
* var stream = objectMode( log );
*
* stream.write( {'value': 'a'} );
* stream.write( {'value': 'b'} );
* stream.write( {'value': 'c'} );
*
* stream.end();
*
* // prints: index: 0
* // prints: {'value': 'a'}
* // prints: index: 1
* // prints: {'value': 'b'}
* // prints: index: 2
* // prints: {'value': 'c'}
*/
function objectMode( options, clbk ) {
var opts;
var cb;
if ( arguments.length > 1 ) {
if ( !isObject( options ) ) {
throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
}
opts = assign( {}, options );
cb = clbk;
} else {
opts = {};
cb = options;
}
opts.objectMode = true;
return new Stream( opts, cb );
}
// EXPORTS //
module.exports = objectMode;