Either<L, R>.fromNullable constructor

Either<L, R>.fromNullable(
  1. R? r,
  2. L onNull(
      )
    )

    If r is null, then return the result of onNull in Left. Otherwise return Right(r).

    Implementation

    factory Either.fromNullable(R? r, L Function() onNull) =>
    r != null ? Either.of(r) : Either.left(onNull());