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| import { useCallback, useState } from 'react' | |
| export type MapOrEntries<K, V> = Map<K, V> | [K, V][] | |
| // Public interface | |
| export interface Actions<K, V> { | |
| set: (key: K, value: V) => void | |
| setAll: (entries: MapOrEntries<K, V>) => void | |
| remove: (key: K) => void | |
| reset: Map<K, V>['clear'] | |
| } | |
| // We hide some setters from the returned map to disable autocompletion | |
| type Return<K, V> = [Omit<Map<K, V>, 'set' | 'clear' | 'delete'>, Actions<K, V>] | |
| function useMap<K, V>( | |
| initialState: MapOrEntries<K, V> = new Map(), | |
| ): Return<K, V> { | |
| const [map, setMap] = useState(new Map(initialState)) | |
| const actions: Actions<K, V> = { | |
| set: useCallback((key, value) => { | |
| setMap(prev => { | |
| const copy = new Map(prev) | |
| copy.set(key, value) | |
| return copy | |
| }) | |
| }, []), | |
| setAll: useCallback(entries => { | |
| setMap(() => new Map(entries)) | |
| }, []), | |
| remove: useCallback(key => { | |
| setMap(prev => { | |
| const copy = new Map(prev) | |
| copy.delete(key) | |
| return copy | |
| }) | |
| }, []), | |
| reset: useCallback(() => { | |
| setMap(() => new Map()) | |
| }, []), | |
| } | |
| return [map, actions] | |
| } | |
| export default useMap |
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