Bailing is an error-handling pattern that takes the middle path between unwrap
and ?
:
- Compared to
unwrap
: Bail willreturn
,continue
, orbreak
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 ?
.
This crate provides six macro variants:
Along with their tiny aliases:
r!
,
rq!
,
c!
,
cq!
,
b!
, and
bq!
.
The macros support Result
, Option
, and bool
types out of the box. You can implement
IntoResult
to extend this to other types.
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 {
tracing::warn!("Bailed at src/example.rs:34:18: `arr.last_mut()` is `None`");
return;
}
}
This crate is available under either of MIT or Apache-2.0 at your choice.