Module async_ext 

Async extensions for error handling (requires async feature) Async extensions for error-rail.

This module provides async-aware error handling utilities that maintain the same lazy attachment philosophy as the sync counterparts.

Note: lazy string formatting is provided by context! / .with_ctx(...). Passing an already-formatted String (e.g. format!(...)) is eager.

Feature Flag

Requires the async feature to be enabled:

[dependencies]
error-rail = { version = "0.8", features = ["async"] }

Examples

use error_rail::prelude_async::*;

#[derive(Debug)]
struct User;

#[derive(Debug)]
struct ApiError;

async fn fetch_from_db(_id: u64) -> Result<User, ApiError> {
    Err(ApiError)
}

async fn fetch_user(id: u64) -> BoxedResult<User, ApiError> {
    fetch_from_db(id)
        .ctx("fetching user from database")
        .await
        .map_err(Box::new)
}

Structs

AsyncErrorPipeline

Async error pipeline for chainable error handling.

ContextFuture

A Future wrapper that attaches error context lazily.

ExponentialBackoff

Exponential backoff retry policy.

FixedDelay

Fixed delay retry policy.

RetryResult

Result of a retry operation with metadata about attempts.

SpanContextFuture

Future wrapper that captures span context on error.

TimeoutError

Error type representing a timeout.

Enums

TimeoutResult

Result type for timeout operations that can fail with either the inner error or a timeout.

Traits

FutureResultExt

Extension trait for attaching error context to async Result-returning futures.

FutureSpanExt

Extension trait for futures that adds tracing span context to errors.

ResultSpanExt

Extension trait for Result types to add span context to errors.

RetryPolicy

Defines a retry policy for async operations.

Functions

instrument_error

Instruments an error with the current span and all its parents.

retry_transient

Retries an async operation using Tokio’s sleep, returning a boxed error.

retry_transient_n

Retries an async operation with a simple count limit using Tokio’s sleep.

retry_transient_unboxed

Retries an async operation using Tokio’s sleep, returning an unboxed error.

retry_with_metadata

Retries an operation with detailed result metadata.

retry_with_policy

Retries an async operation according to a policy when transient errors occur.

try_with_timeout

Executes an async operation with a timeout, returning a TimeoutResult.

validate_all_async

Runs multiple async validations sequentially and collects all errors.

validate_seq_async

Runs async validations sequentially, where each validation depends on the previous result.