<V = never>(): HashSet<V>Creates an empty HashSet.
Example (Creating an empty HashSet)
import { HashSet } from "effect"
const set = HashSet.empty<string>()
console.log(HashSet.size(set)) // 0
console.log(HashSet.isEmpty(set)) // true
// Add some values
const withValues = HashSet.add(HashSet.add(set, "hello"), "world")
console.log(HashSet.size(withValues)) // 2constructors
Source effect/HashSet.ts:1261 lines
export const const empty: <V = never>() => HashSet<V>Creates an empty HashSet.
Example (Creating an empty HashSet)
import { HashSet } from "effect"
const set = HashSet.empty<string>()
console.log(HashSet.size(set)) // 0
console.log(HashSet.isEmpty(set)) // true
// Add some values
const withValues = HashSet.add(HashSet.add(set, "hello"), "world")
console.log(HashSet.size(withValues)) // 2
empty: <function (type parameter) V in <V = never>(): HashSet<V>V = never>() => interface HashSet<out Value>A HashSet is an immutable set data structure that provides efficient storage
and retrieval of unique values. It uses a HashMap internally for optimal performance.
Example (Creating and updating a HashSet)
import { HashSet } from "effect"
// Create a HashSet
const set = HashSet.make("apple", "banana", "cherry")
// Check membership
console.log(HashSet.has(set, "apple")) // true
console.log(HashSet.has(set, "grape")) // false
// Add values (returns new HashSet)
const updated = HashSet.add(set, "grape")
console.log(HashSet.size(updated)) // 4
// Remove values (returns new HashSet)
const smaller = HashSet.remove(set, "banana")
console.log(HashSet.size(smaller)) // 2
The HashSet namespace contains type-level utilities and helper types
for working with HashSet instances.
Example (Extracting value types from a HashSet)
import { HashSet } from "effect"
// Create a concrete HashSet for type extraction
const fruits = HashSet.make("apple", "banana", "cherry")
// Extract the value type for reuse
type Fruit = HashSet.HashSet.Value<typeof fruits> // string
// Use extracted type in functions
const processFruit = (fruit: Fruit) => {
return `Processing ${fruit}`
}
HashSet<function (type parameter) V in <V = never>(): HashSet<V>V> = import internalinternal.const empty: <
V = never
>() => internal.HashSet<V>
Referenced by 2 symbols