Namespace Collections

This module includes a variety of techniques for storing and retrieving data.

Helper functions for working with in-built Javascript collections

• Maps
• Arrays

MutableSet

Like a regular array, a set can store many items. However, duplicate items are ignored - it only keeps unique items. ixfx's Sets.ISetMutable allows for considering items as identical by value, not just by reference as the default JS Set operates

• Sets.mutable: Create a Sets.ISetMutable

CircularArray

circularArray extends a regular array, but only keeps the last x number of items.

Ordered collections

Queues: a list of ordered data, like a bakery queue

• Create with Queues.immutable or Queues.mutable

Stacks: a list of ordered data, like a stack of plates

• Create with Stacks.immutable or Stacks.mutable

Both queue and stack come in mutable and immutable varieties and can limit items stored in varies ways.

Map

Maps.IMapImmutable is a slight variant of the usual JS Map. It allows for a custom logic for computing keys for items based on a function.

• Create with Maps.immutable or Maps.mutable

Maps.ExpiringMap has the same semantics as a regular map, but can automatically remove items if they haven't been set/get for a given interval, and/or if a capacity limit is reached.

• Create with Maps.expiringMap

Map-of

Maps.IMapOf allows for several values to be stored under a single key. Unlike a regular JS Map which only allows a single value per key. IMapOfMutable also has events for listening to changes in the data.

• Maps.ofArrayMutable: Holds any number of items under a given key
• Maps.ofSetMutable: Holds any number of unique items under a given key
• Maps.ofCircularMutable: Holds the most recent x items under a given key

For cases where events are not needed consider Maps.mapOfSimpleMutable. This is a bit more lightweight.

Example: Importing

// If library is stored two directories up under `ixfx/`
import {map} from '../../ixfx/dist/collections.js';
// Import from web
import {map} from 'https://unpkg.com/ixfx/dist/collections.js'
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