AsyncData<Result<Ok, Error>>

A AsyncData can contain a Result (e.g. to represent an asynchronous value that can fail). We provide some utility functions to deal with that case without having to unwrap the AsyncData result.

note

You can still use all the regular AsyncData methods. The following helpers simply removes the need to unwrap the contained result.

Methods

.mapOkToResult(f)

AsyncData<Result<A, E>>.mapOkToResult<B, F>(
  func: (value: A) => Result<B, F>,
): AsyncData<Result<B, E | F>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Ok and returning Result<ReturnValue, Error> and returns a new AsyncData<Result<ReturnValue, Error>>

Examples

AsyncData.Done(Result.Ok(3)).mapOkToResult((ok) => {
  return Result.Ok(ok * 2);
});
// AsyncData<Result.Ok<6>>

AsyncData.Done(Result.Ok(3)).mapOkToResult((ok) =>
  isEven(ok) ? Result.Ok(ok) : Result.Error("Odd number");
);
// AsyncData<Result.Error<"Odd number">>

.mapErrorToResult(f)

AsyncData<Result<A, E>>.mapErrorToResult<B, F>(
  func: (value: E) => Result<B, F>,
): AsyncData<Result<A | B, F>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Error and returning Result<ReturnValue, Error> and returns a new AsyncData<Result<ReturnValue, Error>>

Examples

AsyncData.Done(Result.Error(3)).mapErrorToResult((error) => {
  return Result.Ok(ok * 2);
});
// AsyncData<Result.Ok<6>>

AsyncData.Done(Result.Error(3)).mapErrorToResult((error) =>
  isEven(error) ? Result.Ok(error) : Result.Error("Odd number");
);
// AsyncData<Result.Error<"Odd number">>

.mapOk(f)

AsyncData<Result<A, E>>.mapOk<B>(
  func: (value: A) => B,
): AsyncData<Result<B, E>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Ok and returning ReturnValue and returns a new AsyncData<Result<ReturnValue, Error>>

Examples

AsyncData.Done(Result.Ok(3)).mapOk((ok) => {
  return ok * 2;
});
// AsyncData<Result.Ok<6>>

AsyncData.Done(Result.Error("something")).mapOk((ok) => {
  return ok * 2;
});
// AsyncData<Result.Error<"something">>

.mapError(f)

AsyncData<Result<A, E>>.mapError<F>(
  func: (value: E) => F,
): AsyncData<Result<A, F>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Error and returning ReturnValue and returns a new AsyncData<Result<Ok, ReturnValue>>

Examples

AsyncData.Done(Result.Error(3)).mapError((error) => {
  return error * 2;
});
// AsyncData<Result.Error<6>>

AsyncData.Done(Result.Ok("something")).mapError((ok) => {
  return ok * 2;
});
// AsyncData<Result.Ok<"something">>

.flatMapOk(f)

AsyncData<Result<A, E>>.mapError<B, F>(
  func: (value: A) => AsyncData<Result<B, F>>,
): AsyncData<Result<B, E | F>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Ok returning a AsyncData<Result<ReturnValue, Error>>

Examples

AsyncData.Done(Result.Ok(3)).flatMapOk((ok) =>
  AsyncData.Done(Result.Ok(ok * 2)),
);
// AsyncData<Result.Ok<6>>

AsyncData.Done(Result.Ok(3)).flatMapOk((ok) =>
  AsyncData.Done(Result.Error("Nope")),
);
// AsyncData<Result.Error<"Nope">>

AsyncData.Done(Result.Error("Error")).flatMapOk((ok) =>
  AsyncData.Done(Result.Ok(ok * 2)),
);
// AsyncData<Result.Error<"Error">>

.flatMapError(f)

AsyncData<Result<A, E>>.mapError<B, F>(
  func: (value: E) => AsyncData<Result<B, F>>,
): AsyncData<Result<A | B, F>>

Takes a AsyncData<Result<Ok, Error>> and a f function taking Error returning a AsyncData<Result<Ok, ReturnValue>>

Examples

AsyncData.Done(Result.Ok(3)).flatMapError((error) =>
  AsyncData.Done(Result.Ok(ok * 2)),
);
// AsyncData<Result.Ok<3>>

AsyncData.Done(Result.Error("Error")).flatMapError((error) =>
  AsyncData.Done(Result.Error("Nope")),
);
// AsyncData<Result.Error<"Nope">>

AsyncData.Done(Result.Error("Error")).flatMapError((error) =>
  AsyncData.Done(Result.Ok(1)),
);
// AsyncData<Result.Ok<1>>

Cheatsheet

Method	Input	Function input	Function output	Returned value
mapOkToResult	AsyncData(Ok(x))	x	Ok(y)	AsyncData(Ok(y))
mapOkToResult	AsyncData(Ok(x))	x	Error(f)	AsyncData(Error(f))
mapOkToResult	AsyncData(Error(e))	not provided	not executed	AsyncData(Error(e))
mapErrorToResult	AsyncData(Error(e))	e	Ok(y)	AsyncData(Ok(y))
mapErrorToResult	AsyncData(Error(e))	e	Error(f)	AsyncData(Error(f))
mapErrorToResult	AsyncData(Ok(x))	not provided	not executed	AsyncData(Ok(x))
mapOk	AsyncData(Ok(x))	x	y	AsyncData(Ok(y))
mapOk	AsyncData(Error(e))	not provided	not executed	AsyncData(Error(e))
mapError	AsyncData(Ok(x))	not provided	not executed	AsyncData(Ok(x))
mapError	AsyncData(Error(e))	e	f	AsyncData(Error(f))
flatMapOk	AsyncData(Ok(x))	x	AsyncData(Ok(y))	AsyncData(Ok(y))
flatMapOk	AsyncData(Ok(x))	x	AsyncData(Error(f))	AsyncData(Error(f))
flatMapOk	AsyncData(Error(e))	not provided	not executed	AsyncData(Error(e))
flatMapError	AsyncData(Ok(x))	not provided	not executed	AsyncData(Ok(x))
flatMapError	AsyncData(Error(e))	e	AsyncData(Ok(y))	AsyncData(Ok(y))
flatMapError	AsyncData(Error(e))	e	AsyncData(Error(f))	AsyncData(Error(f))