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option-t

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A toolkit of Nullable/Option/Result type implementation in ECMAScript. Their APIs are inspired by Rust's `Option<T>` and `Result<T, E>`.

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import type { AsyncTransformFn } from '../internal/function.js'; import { type Result } from './result.js'; export type ResultAsyncTryTransformFn<in T, out U, out E> = AsyncTransformFn<T, Result<U, E>>; /** * Returns `Promise<Err(E)>` if the _input_ is `Err(E)`, * otherwise calls _transformer_ with the value and returns the result. * * XXX: * Some languages call this operation flatmap. * But we don't provide `flatMap()` as alias of this function * to sort with other APIs. */ export declare function andThenAsyncForResult<T, U, E>(input: Result<T, E>, transformer: ResultAsyncTryTransformFn<T, U, E>): Promise<Result<U, E>>;