Module prelude_async 

Async prelude - all async utilities in one import (requires async feature) Async prelude - all async utilities in one import.

This module provides all the async-related items needed for async error handling. It re-exports everything from the sync prelude plus async-specific items.

Usage

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)
}

What’s Included

From Sync Prelude

• Macros: context!, group!, rail!, rail_unboxed!
• Types: ComposableError, ErrorContext, ErrorPipeline
• Traits: ResultExt, BoxedResultExt, IntoErrorContext
• Type Alias: BoxedResult

Async-Specific

• Traits: FutureResultExt - .ctx() and .with_ctx() for futures
• Types: AsyncErrorPipeline, ContextFuture
• Macros: rail_async!, ctx_async!

Async Retry (requires async feature)

• Traits: RetryPolicy
• Types: ExponentialBackoff, FixedDelay
• Functions: retry_with_policy

Async Validation (requires async feature)

• Functions: validate_all_async, validate_seq_async

Tokio Integration (requires ecosystem feature)

• Functions: retry_transient, retry_transient_n, try_with_timeout
• Types: TimeoutResult, TimeoutError

Tracing Integration (requires tracing feature)

• Traits: FutureSpanExt, ResultSpanExt
• Functions: instrument_error

Re-exports

pub use crate::async_ext::AsyncErrorPipeline;

pub use crate::async_ext::ContextFuture;

pub use crate::async_ext::FutureResultExt;

pub use crate::async_ext::retry_with_metadata;

pub use crate::async_ext::retry_with_policy;

pub use crate::async_ext::ExponentialBackoff;

pub use crate::async_ext::FixedDelay;

pub use crate::async_ext::RetryPolicy;

pub use crate::async_ext::RetryResult;

pub use crate::async_ext::validate_all_async;

pub use crate::async_ext::validate_seq_async;

pub use crate::async_ext::retry_transient;

pub use crate::async_ext::retry_transient_n;

pub use crate::async_ext::retry_transient_unboxed;

pub use crate::async_ext::try_with_timeout;

pub use crate::async_ext::TimeoutError;

pub use crate::async_ext::TimeoutResult;

pub use crate::async_ext::instrument_error;

pub use crate::async_ext::FutureSpanExt;

pub use crate::async_ext::ResultSpanExt;

pub use crate::async_ext::SpanContextFuture;

pub use crate::prelude::*;

Macros

ctx_async

Attaches context to a future’s error with format string support.

rail_async

Wraps a future in an AsyncErrorPipeline.