use-set

Create a reactive Set with typed helpers.


Package	`@vizejs/composable/use-set`
Own the source	`vize lib pull composable:use-set`
Runtime exports	`useSet`
Gzip budget	1280 B

Usage

import { useSet } from "@vizejs/composable/use-set";

Runtime contract

Utility	Category	Stability	SSR	Hydration	Cleanup	Targets	Host globals	Uses
`useSet`	state	experimental	safe	stable	none	web, server, worker, native, desktop, terminal	—	—

API

`useSet`

Create a reactive Set with typed helpers. The member type is inferred from the initial items (useSet(["a"]) is a Set<string>); pass a type argument for an initially empty set. Membership checks are tracked per item. The set-algebra helpers return new plain sets and do not require ES2025 Set methods. Purely synchronous state: safe during server rendering (no host globals, no timers) and nothing to dispose.

function useSet<Item = unknown>(initial: Iterable<Item> = []): SetControls<Item>

const selected = useSet<number>();
selected.toggle(3); // true
selected.has(3); // true

Types

`SetControls`

Reactive set wrapper returned by useSet.

Member	Type	Description
`set`	`ReadonlySet<Item>`	Read-only reactive view of the set. `has`, iteration, and `size` on this view are tracked. Members are stored shallowly.
`size`	`ComputedRef<number>`	Number of members.
`values`	`ComputedRef<readonly Item[]>`	Snapshot of the members in insertion order.
`has`	`(item: Item) => boolean`	Whether `item` is a member. Reactive when read inside an effect.
`add`	`(item: Item) => boolean`	Add `item`.
`delete`	`(item: Item) => boolean`	Remove `item`.
`toggle`	`(item: Item, force?: boolean) => boolean`	Add `item` when absent and remove it when present, or force membership. Passing an explicit `undefined` behaves like passing no argument.
`clear`	`() => void`	Remove every member.
`union`	`(other: Iterable<Item>) => Set<Item>`	Members of this set or `other`.
`intersection`	`(other: Iterable<Item>) => Set<Item>`	Members of this set that are also in `other`.
`difference`	`(other: Iterable<Item>) => Set<Item>`	Members of this set that are not in `other`.
`reset`	`() => void`	Restore the creation-time members.