# dechainer

> Functional utilities.

Latest version **0.3.2** (published 2021-12-09) · MIT license · 0 weekly downloads

## Install

```sh
npm install dechainer
pnpm add dechainer
yarn add dechainer
bun add dechainer
```

## Health

**Score 30/100 (F)** — status: abandoned.

Positive: has types; esm support; no vulnerabilities; high quality score.

Warnings: low downloads; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.3.2 |
| Published | 2021-12-09 |
| First published | 2021-08-04 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Node | ^12.22.7 \|\| ^14.18.2 \|\| ^16.13.1 \|\| >=17.2.0 |
| Dependencies | 0 |
| Unpacked size | 73 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 1 |
| Author | Andreas Stassivik |
| Maintainers | stassi |
| Keywords | accessors, arithmetic, functional programming, iteration, predicates |

## Links

- npm: https://www.npmjs.com/package/dechainer
- Repository: https://github.com/Stassi/dechainer
- Homepage: https://github.com/Stassi/dechainer#readme
- Issues: https://github.com/Stassi/dechainer/issues
- npm.io page: https://npm.io/package/dechainer

## Recent versions

- 0.3.2 (latest) — 2021-12-09
- 0.3.1 — 2021-12-08
- 0.3.0 — 2021-12-05
- 0.2.14 — 2021-12-03
- 0.2.13 — 2021-09-07
- 0.2.12 — 2021-08-29
- 0.2.11 — 2021-08-29
- 0.2.10 — 2021-08-29
- 0.2.9 — 2021-08-24
- 0.2.8 — 2021-08-23
- 0.2.7 — 2021-08-23
- 0.2.6 — 2021-08-22
- 0.2.5 — 2021-08-22
- 0.2.4 — 2021-08-21
- 0.2.3 — 2021-08-21
- … 20 more at https://npm.io/package/dechainer/versions

## README

# Dechainer

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**Dechainer** is a [Node.js](https://en.wikipedia.org/wiki/Node.js) [library](<https://en.wikipedia.org/wiki/Library_(computing)>) written in [TypeScript](https://en.wikipedia.org/wiki/TypeScript) containing versatile [utilities](https://en.wikipedia.org/wiki/Utility_software) designed to aid [development](https://en.wikipedia.org/wiki/Software_development) in the [functional programming paradigm](https://en.wikipedia.org/wiki/Functional_programming).

## Installation

```Shell
npm i dechainer
```

## Imports

Contrived examples demonstrating how to import functions and types from this library.

### JavaScript

```javascript
import { identity } from 'dechainer'

const example = identity('a string')
// example === 'a string'
```

### TypeScript

```typescript
import type { IdentityCallback } from 'dechainer'
import { identity } from 'dechainer'

const stringIdentity: IdentityCallback<string> = (param: string): string =>
    identity(param),
  example: string = stringIdentity('a string')
// example === 'a string'
```

## Interface

Partial documentation of functions available in this library.

### async

#### delay

Delay code execution by a specified duration.

- `delayable` is a callback function with an optional `duration` parameter (e.g.: `(duration) => console.log(duration)`).
- `duration` is the time in milliseconds that should elapse before `delayable` is called.

##### Unary

```javascript
await delay({ delayable, duration })
```

##### Binary

Parameters can be provided in any order.

```javascript
await delay(delayable, duration)
// or
await delay(duration, delayable)
```

##### Curried

Parameters can be provided in any order.

```javascript
await delay(delayable)(duration)
// or
await delay(duration)(delayable)
```

#### race

Race asynchronous code execution against a specified [timeout](<https://en.wikipedia.org/wiki/Timeout_(computing)>).

- `contender` is an asynchronous function that resolves only if the elapsed time is less than the `timeout` duration.
- `timeout` is the time in milliseconds that should elapse before a `RangeError` is thrown.

##### Unary

```javascript
await race({ contender, timeout })
```

##### Binary

Parameters can be provided in any order.

```javascript
await race(contender, timeout)
// or
await race(timeout, contender)
```

##### Curried

Parameters can be provided in any order.

```javascript
await race(contender)(timeout)
// or
await race(timeout)(contender)
```

### counter

Counter with optional (im-)persistent internal state and respective tradeoffs. Multiple unique counters of both types may exist without overlapping state.

#### Persistent

Persistent counter that is purely functional and side effect free with a smaller, simpler interface. Resetting is achieved by declaring a new variable. Return value(s) should be stored to be practical.

```javascript
const { decrement, increment, state } = counter({ impersistent: false })
// state === 0
// increment().state === 1
```

##### Methods

Methods returned by calling `counter({ impersistent: false })`, each returning a new persistent counter:

- `decrement` decreases the current value by `1`.
- `increment` increases the current value by `1`.

##### Properties

Properties returned by calling `counter({ impersistent: false })`:

- `state` is a number representing the counter's current value.

#### Impersistent

Impersistent counter that provides many methods that mutate its internal state. However, it only needs to be declared once. State is unique to each counter and not shared globally.

```javascript
const { count, decrement, increment, reset } = counter({ impersistent: true })
// count() === 0
// increment()
// count() === 1
```

##### Methods

Methods returned by calling `counter({ impersistent: true })`:

- `count` returns the counter's current number value.
- `decrement` is a side effect that decreases the internal value by `1`.
- `increment` is a side effect that increases the internal value by `1`.
- `reset` is a side effect that sets the internal value to `0`.

---
_Source: https://npm.io/package/dechainer · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._