https://github.com/parro-it/ai-reduce
Reduce for async iterables.
https://github.com/parro-it/ai-reduce
Last synced: about 1 year ago
JSON representation
Reduce for async iterables.
- Host: GitHub
- URL: https://github.com/parro-it/ai-reduce
- Owner: parro-it
- License: mit
- Created: 2017-11-18T11:00:09.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-12-04T20:19:19.000Z (over 8 years ago)
- Last Synced: 2025-03-27T03:04:28.342Z (about 1 year ago)
- Language: JavaScript
- Homepage:
- Size: 459 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: license
Awesome Lists containing this project
README
# ai-reduce
[](http://travis-ci.org/parro-it/ai-reduce)
[](https://npmjs.org/package/ai-reduce)
> Reduce for async iterables.
The reduce() method applies a function against an accumulator and each element
in the async iterable (from left to right) to reduce it to a single value.
## Async iterable fun
> **_This module is part of
> [Async iterable fun](https://github.com/parro-it/ai-fun), a complete toolset
> of modules to work with async iterables._**
## Usage
_Reduce to an async iterable to the sum of its elements:_
```js
import reduce from("ai-reduce");
const add = (accum, item) => accum + item;
console.log( await reduce([2, 3], add, 1) );
```
This will output 6
## API
### reduce
The reduce() method applies a function against an accumulator and each element
in the async iterable to reduce it to a single promise.
**Parameters**
* `data` **AsyncIterable** The async iterable to reduce
* `reducer`
**[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)**
Function to execute on each element in the async iterable, taking four
arguments: . ```
__accumulator__ - The accumulator accumulates the callback's return values; it is
the accumulated value previously returned in the last invocation of the
callback, or initialValue, if supplied (see below).
__currentValue__ - The current element being processed in the async iterable.
__currentIndex__ - The index of the current element being processed in the async
iterable. Starts at index 0, if an initialValue is provided, and at index 1
otherwise.
__data__ - The async iterable reduce was called upon.
```
* `initialValue` **any** Value to use as the first argument to the first call of
the callback. If no initial value is supplied, the first element in the async
iterable will be used. Calling reduce on an empty async iterable without an
initial value is an error.
Returns
**[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)**
The promise value that results from the reduction.
### with
Higher order function that partially apply `reducer` and `accumulator` arguments
to the reduce function.
**Parameters**
* `reducer`
**[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)**
The reducer argument to partially apply
* `accumulator` **any** The accumulator argument to partially apply
Returns
**[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)**
A `reduce` unary function that take a data argument
## Install
With [npm](https://npmjs.org/) installed, run
```bash
npm install --save ai-reduce
```
## See Also
* [`noffle/common-readme`](https://github.com/noffle/common-readme)
* [`parro-it/ai-fun`](https://github.com/parro-it/ai-fun)
## License
MIT