sokerr 1.0.0

Simple Result Sum Type

SOKERR

Simple OK Err

Simple Result sum type for Dart

Why?

There are already many other packages that offer a similar implementation of a Result type, the problem is that all of them try to do too many things at the same time, like implementing methods that could be simply avoided by using Dart's switch expressions. So I decided to implement my own SIMPLE Result.

I found myself copy-pasting this code on all my new projects and got tired of it. So here we are.

Examples

Return a Result from a function

Future<Result<(), String>> updateTable() async {
  ...
  if (somethingWentWrong) {
    return Err("My error");
  }
  ...

  /// Want to know if successful but don't want to return anything?
  /// return an empty pattern `()`
  return Ok(());
}

Wrap a function

Future<Result<String, Object?>> mySafeFunction() async {
  /// With the result extension you can wrap any
  /// synchronous or asynchronous function and capture the
  /// exceptions thrown by it and the value returned
  final res = await unsafeFunctionFromAPackageIDidNotWrite().result();

  ...

  return switch (res) {
    Ok(:final ok) => () {
        ...
        return Ok("");
      }(),
    Err() => res,
  };
}

How can I map a result?

void main() {
  final Result<Data, ()> res = getResult();

  final orElse = "orElse";

  final mappedValue = switch (res) { Ok(:final ok) => ok.myVal, Err() => orElse };
}