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
let tags = Set.fromArray(["urgent", "bug", "frontend"])

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

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

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

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

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