Module macros 

Error handling macros for context creation Ergonomic macros for creating lazy or structured ErrorContext.

These macros provide convenient shortcuts for attaching rich metadata to errors:

• crate::rail - Wraps a Result-producing block and converts it into a BoxedComposableResult via ErrorPipeline::finish.
• crate::context - Defers formatting until the context is consumed, avoiding unnecessary allocations on the success path.
• crate::location - Automatically captures the current file path and line number using file!() and line!().
• crate::tag - Attaches a short categorical label for filtering and searching.
• crate::group - Creates a lazily-evaluated grouped context that combines multiple fields (message, tags, location, metadata) into one cohesive unit while deferring all formatting until the error occurs.

Examples

use error_rail::{context, rail, group, ErrorPipeline};

let result: Result<(), &str> = Err("failed");
let pipeline = ErrorPipeline::new(result)
    .with_context(context!("user_id: {}", 123))
    .with_context(group!(
        tag("auth"),
        location(file!(), line!()),
        metadata("retry_count", "3")
    ))
    .finish_boxed();

// Equivalent rail! shorthand that also returns a boxed composable result
let _ = rail!({
    Err::<(), &str>("failed")
        .map_err(|err| err)
});