9 releases
0.3.1 | Feb 8, 2023 |
---|---|
0.3.0 | Feb 1, 2023 |
0.2.4 | Nov 4, 2022 |
0.2.3 | Oct 12, 2022 |
0.1.1 | Jun 10, 2022 |
#34 in Rust patterns
30,521 downloads per month
Used in 33 crates
(31 directly)
205KB
3K
SLoC
error-stack
error-stack
is a context-aware error-handling library that supports arbitrary attached user data.
Read our announcement post for the story behind its origins.
The library enables building a Report
around an error as it propagates:
use std::fmt;
use error_stack::{Context, IntoReport, Report, Result, ResultExt};
#[derive(Debug)]
struct ParseExperimentError;
impl fmt::Display for ParseExperimentError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.write_str("invalid experiment description")
}
}
impl Context for ParseExperimentError {}
fn parse_experiment(description: &str) -> Result<(u64, u64), ParseExperimentError> {
let value = description
.parse()
.into_report()
.attach_printable_lazy(|| format!("{description:?} could not be parsed as experiment"))
.change_context(ParseExperimentError)?;
Ok((value, 2 * value))
}
#[derive(Debug)]
struct ExperimentError;
impl fmt::Display for ExperimentError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.write_str("experiment error: could not run experiment")
}
}
impl Context for ExperimentError {}
fn start_experiments(
experiment_ids: &[usize],
experiment_descriptions: &[&str],
) -> Result<Vec<u64>, ExperimentError> {
let experiments = experiment_ids
.iter()
.map(|exp_id| {
let description = experiment_descriptions.get(*exp_id).ok_or_else(|| {
Report::new(ExperimentError)
.attach_printable(format!("experiment {exp_id} has no valid description"))
})?;
let experiment = parse_experiment(description)
.attach_printable(format!("experiment {exp_id} could not be parsed"))
.change_context(ExperimentError)?;
Ok(move || experiment.0 * experiment.1)
})
.collect::<Result<Vec<_>, ExperimentError>>()
.attach_printable("unable to set up experiments")?;
Ok(experiments.iter().map(|experiment| experiment()).collect())
}
fn main() -> Result<(), ExperimentError> {
let experiment_ids = &[0, 2];
let experiment_descriptions = &["10", "20", "3o"];
start_experiments(experiment_ids, experiment_descriptions)?;
Ok(())
}
This will most likely result in an error and print
Error: experiment error: could not run experiment ├╴at examples/demo.rs:51:18 ├╴unable to set up experiments │ ├─▶ invalid experiment description │ ├╴at examples/demo.rs:21:10 │ ╰╴experiment 2 could not be parsed │ ╰─▶ invalid digit found in string ├╴at examples/demo.rs:19:10 ├╴backtrace with 31 frames (1) ╰╴"3o" could not be parsed as experiment ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ backtrace no. 1 0: std::backtrace_rs::backtrace::libunwind::trace at /rustc/e972bc8083d5228536dfd42913c8778b6bb04c8e/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5 1: std::backtrace_rs::backtrace::trace_unsynchronized at /rustc/e972bc8083d5228536dfd42913c8778b6bb04c8e/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5 2: std::backtrace::Backtrace::create at /rustc/e972bc8083d5228536dfd42913c8778b6bb04c8e/library/std/src/backtrace.rs:332:13 3: core::ops::function::FnOnce::call_once at /rustc/e972bc8083d5228536dfd42913c8778b6bb04c8e/library/core/src/ops/function.rs:250:5 4: core::bool::<impl bool>::then at /rustc/e972bc8083d5228536dfd42913c8778b6bb04c8e/library/core/src/bool.rs:71:24 5: error_stack::report::Report<C>::from_frame at ./src/report.rs:288:25 6: error_stack::report::Report<C>::new at ./src/report.rs:274:9 7: error_stack::context::<impl core::convert::From<C> for error_stack::report::Report<C>>::from at ./src/context.rs:83:9 8: <core::result::Result<T,E> as error_stack::result::IntoReport>::into_report at ./src/result.rs:203:31 (For this example: additional frames have been removed)
Usage
Please see the documentation.
For more examples of error-stack
in use, please check out the examples folder.
Contributors
error-stack
was created and is maintained by HASH. As an open-source project, we gratefully accept external contributions and have published a contributing guide that outlines the process. If you have questions, please reach out to us on our Discord server.
License
error-stack
is available under a number of different open-source licenses. Please see the LICENSE file to review your options.
Dependencies
~0–500KB