# fdtrie

> Persistent data structures with fast diffing

Latest version **1.0.0** (published 2022-09-26) · MIT license · 0 weekly downloads

## Install

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

## Health

**Score 20/100 (F)** — status: abandoned.

Positive: esm support; no vulnerabilities.

Warnings: low downloads; no types.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.0.0 |
| Published | 2022-09-26 |
| First published | 2022-09-26 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | ESM + CommonJS |
| Dependencies | 1 |
| Unpacked size | 20.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 0 |
| Author | Andrey Krainyak |
| Maintainers | mode89 |

## Links

- npm: https://www.npmjs.com/package/fdtrie
- Repository: https://github.com/mode89/fdtrie-js
- Issues: https://github.com/mode89/fdtrie-js/issues
- npm.io page: https://npm.io/package/fdtrie

## Dependencies (1)

- [lodash](https://npm.io/package/lodash.md) ^4.17.21

## Recent versions

- 1.0.0 (latest) — 2022-09-26

## README

# fdtrie-js
Persistent data structures with fast diff.

## Usage

Installation
```
npm install fdtrie
```

Import
```js
import {PHashMap} from "fdtrie";
```

Create an empty persistent hash map
```js
const m0  = PHashMap.blank();
```

Add entry into the map (returns new map object)
```js
const m1 = m0.assoc("some-key", "some-value");
```

Remove entry from the map (returns new map object)
```js
const m2 = m1.dissoc("some-key");
```

Get value by key (returns `undefined` if key not found)
```js
const someValue = m1.get("some-key");
```

Get value by key and return `notFound` if key not found
```js
const notFound = {};
const anotherValue = m1.get("another-value", notFound);
```

Count entries
```js
const n = m1.count();
```

Iterate through key-value pairs (returns generator object)
```js
for (const e of m1.entries()) {
    console.log(e.key, e.value);
}
```

Calculate difference (returns a map that holds key-value pairs of the first map, which don't present in the second map)
```js
const m3 = m1.difference(m0);
```

## Testing

Run unit tests
```
npm test
```

Run property-based tests
```
npm run test-props
```

## Benchmarking

Run benchmarks
```
npm run bench
```

Results:
```
CPU: Intel Core i7-8700K
RAM: 32 GB
Ubuntu 18.04
Node v16.17.0

Associate a key with a value
  PHashMap:      52 ms
  ImmutableJS:   56 ms
  Mori:          54 ms
  Native:        7 ms

Get a value by a key
  PHashMap:      9 ms
  ImmutableJS:   11 ms
  Mori:          8 ms
  Native:        1 ms

Delete a key
  PHashMap:      48 ms
  ImmutableJS:   55 ms
  Mori:          54 ms
  Native:        0 ms

Single key difference
  PHashMap:      1 us
  ImmutableJS:   8182 us
  Mori:          6798 us

All keys difference
  PHashMap:      13 ms
  ImmutableJS:   46 ms
  Mori:          29 ms
```

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