fpdart 0.0.4

fpdart: ^0.0.4 copied to clipboard

example/main.dart

import 'package:fpdart/fpdart.dart';

void main() {}

void option() {
  /// Create an instance of [Some]
  final option = Option.of(10);

  /// Create an instance of [None]
  final none = Option<int>.none();

  /// Map [int] to [String]
  final map = option.map((a) => '$a');

  /// Extract the value from [Option]
  final value = option.getOrElse(() => -1);

  /// Pattern matching
  final match = option.match(
    (a) => print('Some($a)'),
    () => print('None'),
  );

  /// Convert to [Either]
  final either = option.toEither(() => 'missing');

  /// Chain computations
  final flatMap = option.flatMap((a) => Option.of(a + 10));

  /// Return [None] if the function throws an error
  final tryCatch = Option.tryCatch(() => int.parse('invalid'));
}

void either() {
  /// Create an instance of [Right]
  final right = Either<String, int>.of(10);

  /// Create an instance of [Left]
  final left = Either<String, int>.left('none');

  /// Map the right value to a [String]
  final mapRight = right.map((a) => '$a');

  /// Map the left value to a [int]
  final mapLeft = right.mapLeft((a) => a.length);

  /// Return [Left] if the function throws an error.
  /// Otherwise return [Right].
  final tryCatch = Either.tryCatch(
    () => int.parse('invalid'),
    (e, s) => 'Error: $e',
  );

  /// Extract the value from [Either]
  final value = right.getOrElse((l) => -1);

  /// Chain computations
  final flatMap = right.flatMap((a) => Either.of(a + 10));

  /// Pattern matching
  final match = right.match(
    (l) => print('Left($l)'),
    (r) => print('Right($r)'),
  );

  /// Convert to [Option]
  final option = right.toOption();
}