JS Data Structure Operations (Mutable/Immutable)

A lightweight (~1kb) set of basic operations defined on a plain js data structures (Object, Array, Map, Set). Provides two sets of operations for your choice: mutable or immutable.

Installation

npm install @sadbox/structure-ops

yarn add @sadbox/structure-ops

How to use

mutable

import { get } from '@sadbox/structure-ops';

const a = { b: 0 };

get(a, 'b'); // 0

immutable

import { set } from '@sadbox/structure-ops/immutable';

const a = { b: 0 };
const b = set(a, 'b', 1); // { b: 1 }

console.log(a); // { b: 0 }
console.log(a === b); // false

API

copy(collection)

Creates a new copy of the collection.

Arguments

• collection (Object | Array | Map | Set) - The collection to copy.

Returns

• (Object | Array | Map | Set) - New copy of the collection.

Example

const a = { b: 0 };

copy(a); // { b: 0 }

---

get(collection, key, [defaultValue])

Gets the value of the collection property.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• key (*) - Key of the property to get.
• [defaultValue] (*) - The value returned if property does not exists.

Returns

• (*) - Resolved value.

Example

const a = { b: 0 };

get(a, 'b'); // 0
get(a, 'c', 'ups'); // ups

---

getIn(collection, path, [defaultValue])

Gets the value at the path of the collection.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• path (* | Array<*>) - Path of the property to get.
• [defaultValue] (*) - The value returned if property does not exists.

Returns

• (*) - Resolved value.

Example

const a = { b: { c: [0] } };

getIn(a, ['b', 'c', 0]); // 0
getIn(a, 'b.c[0]'); // 0
getIn(a, 'b.c.0'); // 0

---

has(collection, key)

Check if key is a direct property of the collection.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• key (*) - Key of the property to check.

Returns

• (boolean) - Returns true if property exists, else false.

Example

const a = { b: 0 };

has(a, 'b'); // true
has(a, 'c'); // false

---

hasIn(collection, path)

Check if path is a direct property of the collection.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• path (* | Array<*>) - Path of the property to check.

Returns

• (boolean) - Returns true if property exists, else false.

Example

const a = { b: { c: [0] } };

hasIn(a, 'b.c[0]'); // true

---

merge(collection, ...sources)

Merges the original collection with sources.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• sources (Object | Array | Map | Set) - One or more collections to merge in.

Returns

• (Object | Array | Map | Set) - Mutable merge mutates and returns the source collection. Immutable merge returns a new collection.

Example

const a = { b: 0, c: 2 };

merge(a, { b: 1 }, { d: 3 }); // { b: 1, c: 2, d: 3 }

---

mergeIn(collection, path, ...sources)

Merges the property at path of the original collection with sources.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• path (*, Array<*>) - Path of the property to merge.
• sources (Object | Array | Map | Set) - One or more collections to merge in.

Returns

• (Object | Array | Map | Set) - Mutable mergeIn mutates and returns the source collection. Immutable mergeIn returns a new collection.

Example

const a = { b: { d: 0 } };

mergeIn(a, 'b', { c: 1 }); // { b: { d: 0, c: 1 } }

---

mergeDeep(collection, ...sources)

Deeply merges the original collection with sources.

Arguments

• collection (Object | Array | Map | Set) - The original collection.
• sources (Object | Array | Map | Set) - One or more collections to merge in.

Returns

• (Object | Array | Map | Set) - Mutable mergeIn mutates and returns the source collection. Immutable mergeIn returns a new collection.

Example

const a = { a: [{ b: 1 }] };
const b = { a: [{ c: 2 }] };

mergeDeep(a, b); // { a: [{ b: 1, c: 2 }] }

---

remove(collection, key)

Removes the property from the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• key (*) - Key of the property to remove.

Returns

• (Object | Array | Map) - Mutable remove mutates and returns the source collection. Immutable remove returns a new collection.

Example

const a = { b: 0, c: 1 };

remove(a, 'b'); // { c: 1 }

---

removeIn(collection, path)

Removes the property at path from the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• path (* | Array<*>) - Path of the property to remove.

Returns

• (Object | Array | Map) - Mutable removeIn mutates and returns the source collection. Immutable removeIn returns a new collection.

Example

const a = { b: { c: 0 } };

removeIn(a, 'b.c'); // { b: {} }

---

set(collection, key, value)

Sets the value of property of the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• key (*) - Key of the property to set.
• value (*) - The value to set.

Returns

• (Object | Array | Map) - Mutable set mutates and returns the source collection. Immutable set returns a new collection.

Example

const a = {};

set(a, 'b', 0); // { b: 0 }

---

setIn(collection, path, value)

Sets the value at path of the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• path (*, Array<*>) - Path of the property to set.
• value (*) - The value to set.

Returns

• (Object | Array | Map) - Mutable setIn mutates and returns the source collection. Immutable setIn returns a new collection.

Example

const a = {};

setIn(a, 'b.c', 0); // { b: { c: 0 } }

---

update(collection, key, updater)

Updates the value of property of the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• key (*) - Key of the property to update.
• updater (Function<(value:*):*>) - The updater function that receive an old value and returns a new value.

Returns

• (Object | Array | Map) - Mutable update mutates and returns the source collection. Immutable update returns a new collection.

Example

const a = { b: [1, 2, 3] };
const updater = value => value.map(v => v ** 2);

update(a, 'b', updater); // { b: [1, 4, 9] }

---

updateIn(collection, path, updater)

Updates the value of property at path of the collection.

Arguments

• collection (Object | Array | Map) - The original collection.
• path (* | Array<*>) - Path of the property.
• updater (Function<(value:*):*>) - The updater function that receive an old value and returns a new value.

Returns

• (Object | Array | Map) - Mutable updateIn mutates and returns the source collection. Immutable updateIn returns a new collection.

Example

const a = { b: { c: 0 } };
const updater = value => [value];

updateIn(a, 'b.c', updater); // { b: c: [0] }