npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

array-fp-utils

v0.6.1

Published

Array utilities for functional programming in TypeScript.

Downloads

1,099

Readme

array-fp-utils

Array utilities for functional programming in TypeScript.

Build Status npm version

Features

  • Battle tested performance;
  • Meant to be used with a proper FP library, such as fp-ts;
  • Extensive tests.

Installation

npm install array-fp-utils

Requirements

  • Node.js v.16+

API

groupBy

import { pipe } from 'fp-ts/lib/function';
import { groupBy } from 'array-fp-utils';

const arr = [
  {
    key: 2,
    score: 2,
  },
  {
    key: 1,
    score: 0.5,
  },
  {
    key: 1,
    score: 1,
  },
];

// group by key, while maintaining array item order
const groupedArr = pipe(
  arr,
  groupBy((item) => item.key)
);

// groupedArr now contains the following
// [
//   [
//     {
//       "key": 2,
//       "score": 2,
//     },
//   ],
//   [
//     {
//       "key": 1,
//       "score": 0.5,
//     },
//     {
//       "key": 1,
//       "score": 1,
//     },
//   ],
// ]

intersect

import { pipe } from 'fp-ts/lib/function';
import { intersect } from 'array-fp-utils';

const arr = ['a', 'b', 'c', 'd', 'e'];
const otherArr = ['b', 'c', 'f'];

// calculates the intersection of two arrays
const intersection = pipe(arr, intersect(otherArr)); // returns ['b', 'c']

intersectWith

import { pipe } from 'fp-ts/lib/function';
import { intersectWith } from 'array-fp-utils';

const arr = [
  { foo: 'a' },
  { foo: 'b' },
  { foo: 'c' },
  { foo: 'd' },
  { foo: 'e' },
];

const otherArr = [{ bar: 'b' }, { bar: 'c' }, { bar: 'f' }];

// calculate the intersection of two arrays using comparator function
const arr = pipe(
  mockData,
  intersectWith(otherArr, (item, otherItem) => item.foo === otherItem.bar)
);

// arr = [{ foo: 'b' }, { foo: 'c' }]

isDistinctArray

import { pipe } from 'fp-ts/lib/function';
import { isDistinctArray } from 'array-fp-utils';

pipe([1, 2, 3], isDistinctArray); // returns true
pipe([1, 1, 2, 3], isDistinctArray); // returns false

isSameValueSet

Indicates whether an array contains the same set of items with another array, irrelevant of position (sorting).

Note: only accepts arrays of primitive values.

Example

import { pipe } from 'fp-ts/lib/function';
import { isSameValueSet } from 'array-fp-utils';

pipe([1, 2, 3], isSameValueSet([3, 2, 1])); // returns true

pipe([1, 2], isSameValueSet([1, 2, 3])); // returns false
pipe([1, 2, 3], isSameValueSet([1, 2, 4])); // returns false

isSameValueSetWith

Indicates whether an array contains the same set of items with another array, irrelevant of position (sorting), using a comparator function.

Example

import { pipe } from 'fp-ts/lib/function';
import { isSameValueSetWith } from 'array-fp-utils';

pipe(
  [{ key: 1 }, { key: 2 }, { key: 3 }],
  isSameValueSetWith([3, 2, 1], (value, otherValue) => value.key === otherValue)
); // returns true

isSubsetOf

import { pipe } from 'fp-ts/lib/function';
import { isSubsetOf } from 'array-fp-utils';

const arr = ['a', 'b', 'c', 'd'];

const isSubset = pipe(['b', 'd'], isSubsetOf(arr)); // returns true
const isSubset = pipe(['a', 'e'], isSubsetOf(arr)); // returns false

isSubsetOfWith

import { pipe } from 'fp-ts/lib/function';
import { isSubsetOfWith } from 'array-fp-utils';

const arr = [
  { foo: 'a' },
  { foo: 'b' },
  { foo: 'c' },
  { foo: 'd' },
  { foo: 'e' },
];
const otherArr = [{ bar: 'b' }, { bar: 'c' }, { bar: 'f' }];

const isSubset = pipe(
  arr,
  isSubsetOfWith(otherArr, (item, otherItem) => item.foo === otherItem.bar)
); // returns false since "f" does not exist in arr

unique

import { pipe } from 'fp-ts/lib/function';
import { unique } from 'array-fp-utils';

const countries = [
  'Greece',
  'Greece',
  'Greece',
  'United States',
  'United Kingdom'
  'United States',
];

// returns ['Greece', 'United Kingdom', 'United State']
const uniqueArray = pipe(countries, unique);

uniqueBy

import { pipe } from 'fp-ts/lib/function';
import { uniqueBy } from 'array-fp-utils';

const users = [
  {
    id: 1,
    name: 'John'
  },
  {
    id: 2,
    name: 'Michael'
  }
  {
    id: 3,
    name: 'Michael'
  }
]

// removes duplicate values from array in FiFo
// returns [{id:1, name: 'John'}, {id:2, name: 'Michael'}]
const uniqueArray = pipe(
  users,
  uniqueBy((user) => user.name)
)

Motivation

This library is a collection of array utils, written with FP principles. They focus on performance instead of compatibility.

The alternative would be to use a library like lodash. However, lodash in an attempt to be backwards compatible with older browsers, falls behind on performance. In addition, lodash/groupBy changes the initial order of the array items.

Contribute

Source code contributions are most welcome. Please open a PR, ensure the linter is satisfied and all tests pass.

We are hiring

Causaly is building the world's largest biomedical knowledge platform, using technologies such as TypeScript, React and Node.js. Find out more about our openings at https://apply.workable.com/causaly/.

License

MIT