Set

Immutable unique collection operations. All functions return new sets — they never mutate the original.

Functions

Function	Signature	Description
Set.empty	() -> Set<T>	Create an empty set
Set.fromArray	Array<T> -> Set<T>	Create a set from an array
Set.toArray	Set<T> -> Array<T>	Convert a set to an array
Set.add	Set<T>, T -> Set<T>	Add an element
Set.remove	Set<T>, T -> Set<T>	Remove an element
Set.has	Set<T>, T -> boolean	Check if an element exists
Set.size	Set<T> -> number	Number of elements
Set.isEmpty	Set<T> -> boolean	True if set has no elements
Set.union	Set<T>, Set<T> -> Set<T>	Union of two sets
Set.intersect	Set<T>, Set<T> -> Set<T>	Intersection of two sets
Set.diff	Set<T>, Set<T> -> Set<T>	Difference (elements in first but not second)

Examples

// Create a set from an array
const tags = Set.fromArray(["urgent", "bug", "frontend"])

// All operations are immutable
const updated = tags
  |> Set.add("backend")
  |> Set.remove("frontend")

// Check membership
const isUrgent = tags |> Set.has("urgent")   // true

// Set operations
const teamA = Set.fromArray(["alice", "bob", "carol"])
const teamB = Set.fromArray(["bob", "carol", "dave"])

const everyone = Set.union(teamA, teamB)       // {"alice", "bob", "carol", "dave"}
const overlap = Set.intersect(teamA, teamB)    // {"bob", "carol"}
const onlyA = Set.diff(teamA, teamB)           // {"alice"}

// Convert back to array
const tagList = tags |> Set.toArray