chore: remove selector api (#9426)

* chore: remove selector api

.changeset/chilly-dolphins-lick.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: remove selector api

packages/svelte/src/internal/client/runtime.js

@@ -1254,105 +1254,6 @@ export function set_signal_status(signal, status) {
 	}
 }
 
-/** @template V */
-class Selector {
-	/** @type {Map<V, Set<import('./types.js').Signal>>} */
-	#consumers_map = new Map();
-
-	/** @type {import('./types.js').Signal<V | null>} */
-	#active_key;
-
-	/** @param {V | null} [key] */
-	constructor(key) {
-		this.#active_key = source(key || null);
-	}
-
-	get current() {
-		return get(this.#active_key);
-	}
-
-	/**
-	 * @param {V | null} key
-	 * @returns {void}
-	 */
-	set(key) {
-		const active_key = this.#active_key;
-		const previous_key = active_key.value;
-		if (previous_key === key) {
-			return;
-		}
-
-		set_signal_value(active_key, key);
-
-		const consumers_map = this.#consumers_map;
-		let consumers = map_get(consumers_map, /** @type {V} */ (previous_key));
-		if (consumers !== undefined) {
-			this.#update_consumers(consumers);
-		}
-
-		consumers = map_get(consumers_map, /** @type {V} */ (key));
-		if (consumers !== undefined) {
-			this.#update_consumers(consumers);
-		}
-	}
-
-	/**
-	 * @param {Set<import('./types.js').Signal>} consumers
-	 * @returns {void}
-	 */
-	#update_consumers(consumers) {
-		let consumer;
-		for (consumer of consumers) {
-			set_signal_status(consumer, DIRTY);
-			if ((consumer.flags & IS_EFFECT) !== 0) {
-				schedule_effect(/** @type {import('./types.js').EffectSignal} */ (consumer), false);
-			} else {
-				mark_signal_consumers(consumer, DIRTY, true);
-			}
-		}
-	}
-
-	/**
-	 * @param {V} key
-	 * @returns {boolean}
-	 */
-	is(key) {
-		const consumers_map = this.#consumers_map;
-		let consumers = map_get(consumers_map, key);
-		if (consumers === undefined) {
-			consumers = new Set();
-			map_set(consumers_map, key, consumers);
-		}
-
-		const consumer = current_consumer;
-		const effect = current_effect;
-		if (effect !== null && consumer !== null && !consumers.has(consumer)) {
-			consumers.add(consumer);
-			push_destroy_fn(effect, () => {
-				const consumers_set = /** @type {Set<import('./types.js').Signal>} */ (consumers);
-				consumers_set.delete(effect);
-				if (consumers_set.size === 0) {
-					map_delete(consumers_map, key);
-				}
-			});
-		}
-		return this.#active_key.value === key;
-	}
-}
-
-/**
- * `selector` allows you to track the currently selected item in a list in a performance optimized manner
- * that runs in constant time (O(1)) - this is only noticable for very large lists.
- *
- * https://svelte-5-preview.vercel.app/docs/functions#selector
- * @template Key
- * @param {Key | null} [key]
- * @returns {Selector<Key>}
- */
-export function selector(key) {
-	return new Selector(key);
-}
-
 /**
  * @template V
  * @param {V | import('./types.js').Signal<V>} val

packages/svelte/src/internal/index.js

@@ -13,7 +13,6 @@ export {
 	user_effect,
 	render_effect,
 	pre_effect,
-	selector,
 	flushSync,
 	bubble_event,
 	safe_equal,

packages/svelte/src/main/main-client.js

@@ -255,12 +255,4 @@ export function afterUpdate(fn) {
 
 // TODO bring implementations in here
 // (except probably untrack — do we want to expose that, if there's also a rune?)
-export {
-	flushSync,
-	createRoot,
-	mount,
-	tick,
-	untrack,
-	onDestroy,
-	selector
-} from '../internal/index.js';
+export { flushSync, createRoot, mount, tick, untrack, onDestroy } from '../internal/index.js';

packages/svelte/src/main/main-server.js

@@ -7,7 +7,6 @@ export {
 	hasContext,
 	mount,
 	onDestroy,
-	selector,
 	setContext,
 	tick,
 	untrack

sites/svelte-5-preview/src/routes/docs/content/01-api/03-functions.md

@@ -23,21 +23,3 @@ To prevent something from being treated as an `$effect`/`$derived` dependency, u
 </script>
 ```
 
-## `selector`
-
-`selector` allows you to track the currently selected item in a list in a performance optimized manner that runs in constant time (`O(1)`). With `selector`, you can immediately determine if an item is selected:
-
-```svelte
-<script>
-	import { selector } from 'svelte';
-
-	let array = $state([1, 2, 3]);
-	let selected = selector();
-</script>
-
-{#each array as item}
-	<button on:click={() => selected.set(item)}>{selected.is(item)}</button>
-{/each}
-
-<p>{selected.current}</p>
-```