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import * as O from 'optics-ts'import { atom } from 'jotai'import type { SetStateAction, WritableAtom } from 'jotai'import { createMemoizeAtom } from '../utils/weakCache'
const memoizeAtom = createMemoizeAtom()
const isFunction = <T>(x: T): x is T & ((...args: any[]) => any) =>  typeof x === 'function'
type NonFunction<T> = [T] extends [(...args: any[]) => any] ? never : T
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<Promise<S>, NonFunction<S>, R>,  callback: (optic: O.OpticFor<S>) => O.Prism<S, any, A>): WritableAtom<A | undefined, SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<Promise<S>, NonFunction<S>, R>,  callback: (optic: O.OpticFor<S>) => O.Traversal<S, any, A>): WritableAtom<A[], SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<Promise<S>, NonFunction<S>, R>,  callback: (    optic: O.OpticFor<S>  ) => O.Lens<S, any, A> | O.Equivalence<S, any, A> | O.Iso<S, any, A>): WritableAtom<A, SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<S, NonFunction<S>, R>,  callback: (optic: O.OpticFor<S>) => O.Prism<S, any, A>): WritableAtom<A | undefined, SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<S, NonFunction<S>, R>,  callback: (optic: O.OpticFor<S>) => O.Traversal<S, any, A>): WritableAtom<A[], SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<S, NonFunction<S>, R>,  callback: (    optic: O.OpticFor<S>  ) => O.Lens<S, any, A> | O.Equivalence<S, any, A> | O.Iso<S, any, A>): WritableAtom<A, SetStateAction<A>, R>
export function focusAtom<S, A, R extends void | Promise<void>>(  baseAtom: WritableAtom<S, NonFunction<S>, R>,  callback: (    optic: O.OpticFor<S>  ) =>    | O.Lens<S, any, A>    | O.Equivalence<S, any, A>    | O.Iso<S, any, A>    | O.Prism<S, any, A>    | O.Traversal<S, any, A>) {  return memoizeAtom(() => {    const focus = callback(O.optic<S>())    const derivedAtom = atom(      (get) => getValueUsingOptic(focus, get(baseAtom)),      (get, set, update: SetStateAction<A>) => {        const newValueProducer = isFunction(update)          ? O.modify(focus)(update)          : O.set(focus)(update)        return set(baseAtom, newValueProducer(get(baseAtom)) as NonFunction<S>)      }    )    return derivedAtom  }, [baseAtom, callback])}
const getValueUsingOptic = <S, A>(  focus:    | O.Lens<S, any, A>    | O.Equivalence<S, any, A>    | O.Iso<S, any, A>    | O.Prism<S, any, A>    | O.Traversal<S, any, A>,  bigValue: S) => {  if (focus._tag === 'Traversal') {    const values = O.collect(focus)(bigValue)    return values  }  if (focus._tag === 'Prism') {    const value = O.preview(focus)(bigValue)    return value  }  const value = O.get(focus)(bigValue)  return value}