https://github.com/coderaiser/mystery
flawless arrays processing
https://github.com/coderaiser/mystery
array functional nodejs
Last synced: about 1 month ago
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flawless arrays processing
- Host: GitHub
- URL: https://github.com/coderaiser/mystery
- Owner: coderaiser
- License: mit
- Created: 2016-06-07T20:06:37.000Z (almost 10 years ago)
- Default Branch: master
- Last Pushed: 2020-01-28T16:07:25.000Z (over 6 years ago)
- Last Synced: 2026-01-17T11:37:35.737Z (4 months ago)
- Topics: array, functional, nodejs
- Language: JavaScript
- Size: 65.4 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: ChangeLog
- License: LICENSE
Awesome Lists containing this project
README
# Mystery [![License][LicenseIMGURL]][LicenseURL] [![NPM version][NPMIMGURL]][NPMURL] [![Dependency Status][DependencyStatusIMGURL]][DependencyStatusURL] [![Build Status][BuildStatusIMGURL]][BuildStatusURL] [![Coverage Status][CoverageIMGURL]][CoverageURL]
Flawless arrays processing.
## Install
`npm i mystery --save`
## Why?
When you use `forEach`, `map`, `filter` you have 2 conses to think about:
- it is not as simple as could be add and remove elements in the middle of array
- you should pass through the array again and again
This is where `mystery` shows up it's proses. It processes elements of an array one-by-one.
So you have only one array walk. Similar to the way of [node.js stream works](https://nodejs.org/api/stream.html),
`mystery` is something like `pipe` it joins all `transforms` which are [event emitters](https://nodejs.org/api/events.html) from the inside.
## How to use?
```js
const mystery = require('mystery');
const {map, filter, take, append, insert} = mystery;
const mapper = mystery([
map((a) => a * a)),
filter((a) => a > 10)),
take(2),
append(['yes', 'you', 'can']),
insert(4, 'definitely')
]);
mapper([1, 2, 3, 4, 5], (array) => {
console.log(array);
// returns
[16, 25, 'yes', 'you', 'definitely', 'can']
});
```
## Transforms
You can use any of built-in transforms or write your own.
Consder simple `head` and `tail` transforms which returns first
and rest elements.
This is how `head` transform could look like:
```js
const mystery = require('mystery');
const head = () => {
return (value, index, emit) => {
if (!index)
emit(value);
}
};
const first = mystery([
head()
]);
first([1, 2, 3, 4, 5], (array) => {
console.log(array);
// result
[1]
});
```
And here is `tail`:
```js
const mystery = require('mystery');
const tail = () => {
return (value, index, emit) => {
if (index)
emit(value);
}
};
const rest = mystery([
tail()
]);
first([1, 2, 3, 4, 5], (array) => {
console.log(array);
// returns
[2, 3, 4, 5]
});
```
You can find more examples at `lib/transforms`.
## License
MIT
[NPMIMGURL]: https://img.shields.io/npm/v/mystery.svg?style=flat
[BuildStatusIMGURL]: https://img.shields.io/travis/coderaiser/mystery/master.svg?style=flat
[DependencyStatusIMGURL]: https://img.shields.io/david/coderaiser/mystery.svg?style=flat
[LicenseIMGURL]: https://img.shields.io/badge/license-MIT-317BF9.svg?style=flat
[NPMURL]: https://npmjs.org/package/mystery "npm"
[BuildStatusURL]: https://travis-ci.org/coderaiser/mystery "Build Status"
[DependencyStatusURL]: https://david-dm.org/coderaiser/mystery "Dependency Status"
[LicenseURL]: https://tldrlegal.com/license/mit-license "MIT License"
[CoverageURL]: https://coveralls.io/github/coderaiser/mystery?branch=master
[CoverageIMGURL]: https://coveralls.io/repos/coderaiser/mystery/badge.svg?branch=master&service=github