97 lines
3.1 KiB
JavaScript
97 lines
3.1 KiB
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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
'use strict';
|
||
|
|
|
||
|
|
// MODULES //
|
||
|
|
|
||
|
|
var factory = require( './factory.js' );
|
||
|
|
|
||
|
|
|
||
|
|
// MAIN //
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Applies a function against an accumulator and each element in a collection and return the accumulated result.
|
||
|
|
*
|
||
|
|
* ## Notes
|
||
|
|
*
|
||
|
|
* - If a provided function calls the provided callback with a truthy error argument, the function suspends execution and immediately calls the `done` callback for subsequent error handling.
|
||
|
|
* - This function does **not** guarantee that execution is asynchronous. To do so, wrap the `done` callback in a function which either executes at the end of the current stack (e.g., `nextTick`) or during a subsequent turn of the event loop (e.g., `setImmediate`, `setTimeout`).
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* @param {Collection} collection - input collection
|
||
|
|
* @param {*} initial - initial value
|
||
|
|
* @param {Options} [options] - function options
|
||
|
|
* @param {*} [options.thisArg] - execution context
|
||
|
|
* @param {PositiveInteger} [options.limit] - maximum number of pending invocations at any one time
|
||
|
|
* @param {boolean} [options.series=true] - boolean indicating whether to wait for a previous invocation to complete before invoking a provided function for the next element in a collection
|
||
|
|
* @param {Function} fcn - function to invoke for each element in a collection
|
||
|
|
* @param {Callback} done - function to invoke upon completion
|
||
|
|
* @throws {TypeError} first argument must be a collection
|
||
|
|
* @throws {TypeError} options argument must be an object
|
||
|
|
* @throws {TypeError} must provide valid options
|
||
|
|
* @throws {TypeError} second-to-last argument must be a function
|
||
|
|
* @throws {TypeError} last argument must be a function
|
||
|
|
* @returns {void}
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* var readFile = require( '@stdlib/fs/read-file' );
|
||
|
|
*
|
||
|
|
* function done( error, acc ) {
|
||
|
|
* if ( error ) {
|
||
|
|
* throw error;
|
||
|
|
* }
|
||
|
|
* console.log( acc.count );
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* function read( acc, file, next ) {
|
||
|
|
* var opts = {
|
||
|
|
* 'encoding': 'utf8'
|
||
|
|
* };
|
||
|
|
* readFile( file, opts, onFile );
|
||
|
|
*
|
||
|
|
* function onFile( error ) {
|
||
|
|
* if ( error ) {
|
||
|
|
* return next( null, acc );
|
||
|
|
* }
|
||
|
|
* acc.count += 1;
|
||
|
|
* next( null, acc );
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* var files = [
|
||
|
|
* './beep.js',
|
||
|
|
* './boop.js'
|
||
|
|
* ];
|
||
|
|
* var acc = {
|
||
|
|
* 'count': 0
|
||
|
|
* };
|
||
|
|
* reduceAsync( files, acc, read, done );
|
||
|
|
*/
|
||
|
|
function reduceAsync( collection, initial, options, fcn, done ) {
|
||
|
|
if ( arguments.length < 5 ) {
|
||
|
|
return factory( options )( collection, initial, fcn );
|
||
|
|
}
|
||
|
|
factory( options, fcn )( collection, initial, done );
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// EXPORTS //
|
||
|
|
|
||
|
|
module.exports = reduceAsync;
|