nidula 0.1.1

A lightweight Dart library for Rust-like Option/Result types. Supports exhaustive pattern matching and compile-time safe, chainable None/Err propagation.

example/nidula_example.dart

import 'package:nidula/nidula.dart';

Result<double, String> example(Result<double, String> r) {
  return Result.syncErrPropagationScope<double, String>((t) {
    r = Ok(r.unwrapOrPropagateErr(t) / 2);
    return Ok(r.unwrapOrPropagateErr(t));
  });
}

void main() {
  print('#1: ${example(Err('s'))}'); // #1: Err(s)
  print('#2: ${example(Ok(14))}'); // #2: Ok(7.0)

  print(Result.syncErrPropagationScope<I, String>((t) {
    return Ok(
      Ok<I, String>(I())
          .unwrapOrPropagateErr(t)
          .make()
          .unwrapOrPropagateErr(t)
          .make()
          .unwrapOrPropagateErr(t),
    );
  }));

}

class I {
  Result<I, String> make() {
    return Ok(I());
  }
}