mapLeft<TL> method

Future<Either<TL, R>> mapLeft<TL>(
  1. FutureOr<TL> fnL(
    1. L left
    )
)

Transform value of Left

Implementation

Future<Either<TL, R>> mapLeft<TL>(FutureOr<TL> Function(L left) fnL) =>
    this.then((either) => either.mapLeftAsync(fnL));