core/result library

Re-exports the Result<T> / Failure types from resilify.

token_keeper 1.1.0 unified its result type with the resilify package so that callers can share a single Result / Failure model across token management and the rest of their networking stack.

Heads up — dart:core.Error collision. The Error variant from resilify shadows dart:core.Error. If you need both in the same file, hide one at the import site:
import 'package:token_keeper/token_keeper.dart';
import 'dart:core' hide Error;

Classes

CircuitBreaker: Wraps an unreliable operation with the circuit-breaker resilience pattern: after failureThreshold consecutive failures the breaker "opens" and fast-fails calls for resetTimeout; one probe call is then admitted, and its outcome decides whether the breaker closes or reopens.
Error<T>: The failed variant of a Result.
Failure: An immutable, structured description of why an operation failed.
Result<T>: A type-safe representation of an operation that either produced a value of type T (Success) or failed with a Failure (Error).
ResultCache<K, V>: An in-memory cache for Result values with optional TTL expiry.
ResultDeduplicator<K, V>: Ensures only one Future<Result<V>> is in flight per key at any time.
RetryHelper: Static helpers for retrying Result-returning async operations.
Success<T>: The successful variant of a Result.

Enums

CircuitBreakerState: State of a CircuitBreaker.
FailureKind: Categorical tag describing what kind of thing went wrong, independent of any HTTP status code or human-readable message.
FailureType: Structural category of a Failure.

Extensions

FlattenResultX on Result<Result<T>>: Collapses a nested Result into a single layer. If the outer is an Error, it is returned unchanged; otherwise the inner Result is returned.
FutureResultX on Future<Result<T>>: Async helpers on Future<Result<T>>.
FutureToResultX on Future<T>: Bridges a regular Future<T> (which signals failure by throwing) into a Future<Result<T>> without writing Result.tryRunAsync(() => future) at every call site.
ResultAsyncX on Result<T>: Async transformations applied directly to a Result (not a future).
ResultListX on Result<List<T>>: Extensions that operate on the elements inside a successful list result.
ResultX on Result<T>: Synchronous helpers on Result.
StreamResultX on Stream<Result<T>>: Extensions for working with streams of Result values without unwrapping each event manually.

Typedefs

LogCallback = void Function(String line): Sink for log lines emitted by resilify interceptors and handlers.

Exceptions / Errors

ResultUnwrapException: Thrown by ResultX.getOrThrow when called on an Error.