ruqe 1.1.2

Ruqe brings the convenient types and methods found in Rust into Dart, such as the Result, Option, pattern-matching, etc.

ruqe

Ruqe brings the convenient types and methods found in Rust into Dart, such as the Result, Option, pattern-matching, etc. Additionally, the library provides an excellent concept for modeling errors without resorting to exceptions.

Getting started

In your Dart/Flutter project, add the dependency to your pubspec.yaml

dependencies:
  ruqe: ^1.1.2

import with

import 'package:ruqe/ruqe.dart';

Basic usage

#[ Recoverable and Unrecoverable Errors ]

In Ruqe, there is a clear distinction between recoverable and unrecoverable errors.

1. Recoverable errors:

Recoverable errors do not cause a program to terminate completely. Ruqe makes unrecoverable error recoverable by matching the returned value of type Result and Option with the .match<T> convenient method.

void main() {
  /// Calling [stringToNum] with an alphanumeric
  /// data will trigger an exception.
  var trigger = stringToNum("%65");

  /// With pattern matching, we were able to recover from the
  /// exception thrown from calling [int.parse()] and return
  /// 0 instead.
  var result = trigger.match<int?>(
    ok: (value) => value,
    err: (_) => 0,
  );

  print("Result: $result"); // Result: 0
}

Result<int, String> stringToNum(String str) {
  try {
    var value = int.parse(str);
    return Ok(value);
  } catch (err) {
    return Err("Value is none");
  }
}

2. Unrecoverable errors:

Unrecoverable errors cause a program to terminate immediately. In Ruqe, [Panic] terminates the program when it comes across with an unrecoverable error.

What can trigger a panic?

typedef ListMap = List<Map<String, String>>;
typedef AppError = String;

var data = [
  {"first_name": "Tunbnad", "last_name": "Smart"},
  {"first_name": "Lambo", "last_name": "Turnner"}
];

void main() {
  var firstNames1 = getFirstName(data);
  print(firstNames1.unwrap()); // [Tunbnad, Lambo]

  /// Unwrapping a value of [Option] that is [None]
  /// will trigger a [Panic] and terminate the program.
  var firstNames2 = getFirstName([]);
  firstNames2.unwrap(); // panic with `[error]: an error occured!`
}

/// Returns a [Result] that is [Err] if [ListMap] is empty.
Result<List<String?>, AppError> getFirstName(ListMap data) {
  if (data.isNotEmpty) {
    return Ok(data.map((user) => user["first_name"]).toList());
  } else {
    return Err("[error]: an error occured!");
  }
}