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import { atom } from 'jotai'import type { Atom } from 'jotai'import { createMemoizeAtom } from './weakCache'
type Awaited<T> = T extends Promise<infer V> ? Awaited<V> : T
const memoizeAtom = createMemoizeAtom()
export function selectAtom<Value, Slice>(  anAtom: Atom<Value>,  selector: (v: Awaited<Value>) => Slice,  equalityFn: (a: Slice, b: Slice) => boolean = Object.is): Atom<Slice> {  return memoizeAtom(() => {    // TODO we should revisit this for a better solution than refAtom    const refAtom = atom(() => ({} as { prev?: Slice }))    const derivedAtom = atom((get) => {      const slice = selector(get(anAtom) as Awaited<Value>)      const ref = get(refAtom)      if ('prev' in ref && equalityFn(ref.prev as Slice, slice)) {        return ref.prev as Slice      }      ref.prev = slice      return slice    })    return derivedAtom  }, [anAtom, selector, equalityFn])}