effect-io-ai

Package: effect
Module: MutableHashMap

MutableHashMap.MutableHashMap

A mutable hash map that stores key-value pairs and supports both referential and Effect structural equality.

When to use

Use as a mutable key-value map when in-place updates are acceptable and keys may rely on Effect structural equality.

Details

Operations mutate the map in place. Keys that implement Equal / Hash can be looked up structurally; other keys use normal JavaScript reference or primitive equality.

Example (Using a mutable hash map)

import { MutableHashMap } from "effect"

// Create a mutable hash map with string keys and number values
const map: MutableHashMap.MutableHashMap<string, number> = MutableHashMap
  .empty()

// Add some data
MutableHashMap.set(map, "count", 42)
MutableHashMap.set(map, "total", 100)

// Use as iterable
for (const [key, value] of map) {
  console.log(`${key}: ${value}`)
}
// Output:
// count: 42
// total: 100

// Convert to array
const entries = Array.from(map)
console.log(entries) // [["count", 42], ["total", 100]]

See

• empty for creating an empty mutable hash map
• get for reading values by key
• set for mutating entries by key

Signature

export interface MutableHashMap<out K, out V> extends Iterable<[K, V]>, Pipeable, Inspectable {
  readonly [TypeId]: typeof TypeId
  readonly backing: Map<K, V>
  readonly buckets: Map<number, NonEmptyArray<K>>
}

Source

Since v2.0.0