tiny_bail

Bailing is an error-handling pattern that takes the middle path between unwrap and ?:

• Compared to unwrap: Bail will return, continue, or break instead of panicking.
• Compared to ?: Bail will log or ignore the error instead of propagating it.

The middle path avoids unwanted panics without the ergonomic challenges of propagating errors with ?.

Getting started

This crate provides six macro variants:

• or_return!
• or_return_quiet!
• or_continue!
• or_continue_quiet!
• or_break!
• or_break_quiet!

Along with their tiny aliases: r!, rq!, c!, cq!, b!, and bq!.

The macros support bool, Option, and Result types out of the box. Implement Success to extend this to other types.

You can specify a return value as an optional first argument to the macro, or omit it to default to Default::default()—which even works in functions with no return value.

Example

use tiny_bail::prelude::*;

// With `tiny_bail`:
fn increment_last(arr: &mut [i32]) {
    *r!(arr.last_mut()) += 1;
}

// Without `tiny_bail`:
fn increment_last_manually(arr: &mut [i32]) {
    if let Some(x) = arr.last_mut() {
        *x += 1;
    } else {
        println!("Bailed at src/example.rs:34:18: `arr.last_mut()`");
        return;
    }
}

License

This crate is available under either of MIT or Apache-2.0 at your choice.