supercharge / set

An Array-aligned Set class and the one JavaScript should have shipped

Set

An Array-aligned Set class and the one JavaScript should have shipped

Installation · Docs · Usage

Follow @marcuspoehls and @superchargejs for updates!

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Introduction

The @supercharge/set package provides an improved Set implementation.

• aligned with the Array class instead of Map
• provides helpful methods like .map(callback), .filter(callback), .find(callback), .isEmpty(), and many more.
• compares values for deep equality and not reference
• it’s the Set class JavaScript should have shipped

Installation

npm i @supercharge/set

Resources

• Documentation

Quick Usage Overview

Using @supercharge/set is pretty straightforward. The package exports a Set class providing all methods to interact with the set.

const Set = require('@supercharge/set')

const users = new Set()

users.isEmpty() // true

users
  .add({ id: 1, name: 'Marcus' })
  .add({ id: 2, name: 'Norman' })
  .add({ id: 3, name: 'Christian' })

users.isNotEmpty() // true

const usernames = users.map(user => {
  return user.name
})
// [ 'Marcus', 'Norman', 'Christian' ]

const marcus = users.find(user => {
  return user.name === 'Marcus'
})
// { id: 1, name: 'Marcus' }

Contributing

Do you miss a function? We very much appreciate your contribution! Please send in a pull request 😊

1. Create a fork
2. Create your feature branch: git checkout -b my-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request 🚀

License

MIT © Supercharge

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superchargejs.com  ·  GitHub @supercharge  ·  Twitter @superchargejs

set's Issues

Add "concat" method

Add a new .concat(...values) method that appends the given values to the end of the set.

Example

Set.of([1, 2, 3]).concat([4, 5]).toArray()
// [1, 2, 3, 4, 5]

Set.of([1, 2, 3]).concat(4, 5).toArray()
// [1, 2, 3, 4, 5]

Add "last" method

Add a new .last(predicate?: (value: T, set: SuperchargedSet) method returns the last item in the set. If a predicate function is provided, return the last item found by predicate.

Example

Set.of([1, 2, 3]).last()
// 3

Set.of([5, 4, 3, 2, 1]).last(value => {
  return value > 3
})
// 4

Add "count" method

Add a new .count(predicate: T => boolean) method that returns the number of items matching the given predicate

Example

Set.of([1, 2, 3, 4, 5]).count(value => {
  return value > 3
})

// 2

Add method: any

Implement an any method that returns true if at least one item in the set matches a given predicate function, otherwise false.

Requirements

• please use the prepared method-any branch (contains tests)
• make sure the automated tests pass

Add "first" method

Add a new .first(predicate?: (value: T, set: SuperchargedSet) method returns the first item in the set. If a predicate function is provided, return the first item found by predicate. When providing a predicate function, .first(predicate) is an alias for .find(predicate).

Example

Set.of([1, 2, 3]).first()
// 1

Set.of([1, 2, 3, 4, 5]).first(value => {
  return value > 3
})
// 4

Add method: findLast

Implement a findLast method that returns the last item in the set matching the given predicate function. Returns undefined if no item matching the predicate was found in the set.

Requirements

• please use the prepared method-findLast branch (contains tests)
• make sure the automated tests pass

Add "includes" method

Add a new .includes(value: T | predicate: T => boolean) method that determines whether the set includes the given value or a value identified by the predicate function.

Returns true if the value is found in the collection or the predicate function returns an item from the collection. Returns false otherwise.

Example

Set.of([1, 2, 3, 4, 5]).includes(2)
// true

Set.of([1, 2, 3, 4, 5]).includes(value => {
  return value > 3
})
// true

Set.of([1, 2, 3, 4, 5]).includes(value => {
  return value === 0
})
// false

Add method: findLastIndex

Implement a findLastIndex method that returns the index of the last item in the set matching the given predicate function. Returns -1 if no item matching the predicate was found in the set.

Requirements

• please use the prepared method-findLastIndex branch (contains tests)
• make sure the automated tests pass

Add method: all

Implement an all method that returns true if all items in the set match a given predicate function, otherwise false.

Requirements

• please use the prepared method-all branch (contains tests)
• make sure the automated tests pass

Add method: intersect

Implement an intersect method that returns a set containing all items that are contained in all collections, the given set and and all candidate sets.

Requirements

• please use the prepared method-intersect branch (contains tests)
• make sure the automated tests pass

Add "reduce" method

Add a new .reduce(operation, initialValue) method executes a reducer function on each item of the set, resulting in a single output value.

The method signature may look like this (I’m writing this freestyle, you may need to refine it when working in the code 😄 )

reduce<U>((operation: (previous: U, current: T, set: Set), initial: U): U`

Example

Set.of([1, 2, 3, 4]).reduce((sum, value) => {
  return sum + value
}, 0)

// 10