d2542c9a62
Squash the current repository state back into one baseline commit while preserving the README reframing and repository contents. Constraint: User explicitly requested a single squashed commit with subject "asdf" Confidence: high Scope-risk: broad Reversibility: clean Directive: This commit intentionally rewrites published history; coordinate before future force-pushes Tested: git status clean; local history rewritten to one commit; force-pushed main to origin and instructkr Not-tested: Fresh clone verification after push
44 lines
1.4 KiB
TypeScript
44 lines
1.4 KiB
TypeScript
/**
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* Tiny listener-set primitive for pure event signals (no stored state).
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*
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* Collapses the ~8-line `const listeners = new Set(); function subscribe(){…};
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* function notify(){for(const l of listeners) l()}` boilerplate that was
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* duplicated ~15× across the codebase into a one-liner.
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*
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* Distinct from a store (AppState, createStore) — there is no snapshot, no
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* getState. Use this when subscribers only need to know "something happened",
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* optionally with event args, not "what is the current value".
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*
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* Usage:
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* const changed = createSignal<[SettingSource]>()
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* export const subscribe = changed.subscribe
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* // later: changed.emit('userSettings')
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*/
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export type Signal<Args extends unknown[] = []> = {
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/** Subscribe a listener. Returns an unsubscribe function. */
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subscribe: (listener: (...args: Args) => void) => () => void
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/** Call all subscribed listeners with the given arguments. */
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emit: (...args: Args) => void
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/** Remove all listeners. Useful in dispose/reset paths. */
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clear: () => void
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}
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export function createSignal<Args extends unknown[] = []>(): Signal<Args> {
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const listeners = new Set<(...args: Args) => void>()
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return {
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subscribe(listener) {
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listeners.add(listener)
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return () => {
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listeners.delete(listener)
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}
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},
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emit(...args) {
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for (const listener of listeners) listener(...args)
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},
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clear() {
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listeners.clear()
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},
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}
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}
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