prepare for 1.0
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Harald Hoyer 2023-07-28 17:08:42 +02:00 committed by GitHub
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31 changed files with 230 additions and 153 deletions

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@ -46,7 +46,7 @@ and you have no idea where it comes from.
With `chainerror`, you can supply a context and get a nice error backtrace:
```rust
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::path::PathBuf;
type BoxedError = Box<dyn std::error::Error + Send + Sync>;
@ -90,6 +90,81 @@ Along with the `Error<T>` struct, `chainerror` comes with some useful helper mac
Debug information is worth it!
## Multiple Output Formats
`chainerror` supports multiple output formats, which can be selected with the different format specifiers:
* `{}`: Display
```text
func1 error calling func2
```
* `{:#}`: Alternative Display
```text
func1 error calling func2
Caused by:
func2 error: calling func3
Caused by:
(passed error)
Caused by:
Error reading 'foo.txt'
Caused by:
entity not found
```
* `{:?}`: Debug
```text
examples/example.rs:50:13: func1 error calling func2
Caused by:
examples/example.rs:25:13: Func2Error(func2 error: calling func3)
Caused by:
examples/example.rs:18:13: (passed error)
Caused by:
examples/example.rs:13:18: Error reading 'foo.txt'
Caused by:
Kind(NotFound)
```
* `{:#?}`: Alternative Debug
```text
Error<example::Func1Error> {
occurrence: Some(
"examples/example.rs:50:13",
),
kind: func1 error calling func2,
source: Some(
Error<example::Func2Error> {
occurrence: Some(
"examples/example.rs:25:13",
),
kind: Func2Error(func2 error: calling func3),
source: Some(
Error<chainerror::AnnotatedError> {
occurrence: Some(
"examples/example.rs:18:13",
),
kind: (passed error),
source: Some(
Error<alloc::string::String> {
occurrence: Some(
"examples/example.rs:13:18",
),
kind: "Error reading 'foo.txt'",
source: Some(
Kind(
NotFound,
),
),
},
),
},
),
},
),
}
```
## Tutorial
Read the [Tutorial](https://haraldh.github.io/chainerror/tutorial1.html)

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@ -1,24 +0,0 @@
[![Crate](https://img.shields.io/crates/v/chainerror.svg)](https://crates.io/crates/chainerror)
[![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/chainerror/)
[![Coverage Status](https://coveralls.io/repos/github/haraldh/chainerror/badge.svg?branch=master)](https://coveralls.io/github/haraldh/chainerror?branch=master)
{{badges}}
# {{crate}}
{{readme}}
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or https://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or https://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.

1
booksrc/LICENSE-APACHE Symbolic link
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@ -0,0 +1 @@
../LICENSE-APACHE

1
booksrc/LICENSE-MIT Symbolic link
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@ -0,0 +1 @@
../LICENSE-MIT

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@ -1,6 +1,6 @@
# ErrorKind to the rescue
To cope with different kind of errors, we introduce the kind of an error `Func1ErrorKind` with an enum.
To cope with different kind of errors, we introduce the `kind` of an error `Func1ErrorKind` with an enum.
Because we derive `Debug` and implement `Display` our `Func1ErrorKind` enum, this enum can be used as
a `std::error::Error`.
@ -8,10 +8,9 @@ a `std::error::Error`.
Only returning `Func1ErrorKind` in `func1()` now let us get rid of `Result<(), Box<Error + Send + Sync>>` and we can
use `ChainResult<(), Func1ErrorKind>`.
In `main` we can now directly use the methods of `ChainError<T>` without downcasting the error first.
In `main` we can now directly use the methods of `chainerror::Error<T>` without downcasting the error first.
Also a nice `match` on `ChainError<T>.kind()` is now possible, which returns `&T`, meaning
`&Func1ErrorKind` here.
Also, a nice `match` on `chainerror::Error<T>.kind()` is now possible, which returns `&T`, meaning `&Func1ErrorKind` here.
~~~rust
{{#include ../examples/tutorial10.rs}}

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@ -21,7 +21,7 @@ which gives us a lot more detail.
To create your own Errors, you might find [crates](https://crates.io) which create enum `Display+Debug` via derive macros.
Also noteworthy is [custom_error](https://crates.io/crates/custom_error) to define your custom errors,
Also, noteworthy is [custom_error](https://crates.io/crates/custom_error) to define your custom errors,
which can then be used with `chainerror`.
~~~rust

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@ -1,6 +1,6 @@
# Deref for the ErrorKind
Because ChainError<T> implements Deref to &T, we can also match on `*e` instead of `e.kind()`
Because chainerror::Error<T> implements Deref to &T, we can also match on `*e` instead of `e.kind()`
or call a function with `&e`
~~~rust
{{#include ../examples/tutorial12.rs}}

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@ -1,6 +1,6 @@
# Writing a library
I would advise to only expose an `mycrate::ErrorKind` and type alias `mycrate::Error` to `ChainError<mycrate::ErrorKind>`
I would advise to only expose an `mycrate::ErrorKind` and type alias `mycrate::Error` to `chainerror::Error<mycrate::ErrorKind>`
so you can tell your library users to use the `.kind()` method as `std::io::Error` does.
If you later decide to make your own `Error` implementation, your library users don't

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@ -25,7 +25,7 @@ along with the `Location` of the `context()` call and returns `Err(newerror)`.
`?` then returns the inner error applying `.into()`, so that we
again have a `Err(Box<Error + Send + Sync>)` as a result.
The `Debug` implementation of `ChainError<T>` (which is returned by `context()`)
The `Debug` implementation of `chainerror::Error<T>` (which is returned by `context()`)
prints the `Debug` of `T` prefixed with the stored filename and line number.
`ChainError<T>` in our case is `ChainError<&str>`.
`chainerror::Error<T>` in our case is `chainerror::Error<&str>`.

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@ -14,13 +14,13 @@ If you compare the output to the previous example, you will see,
that:
~~~
Error: src/main.rs:19: "func1 error"
Error: examples/tutorial2.rs:20:16: func1 error
~~~
changed to just:
~~~
src/main.rs:16: "func1 error"
examples/tutorial3.rs:17:13: func1 error
~~~
This is, because we caught the error of `func1()` in `main()` and print it out ourselves.

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@ -14,5 +14,4 @@ Sometimes you want to inspect the `source()` of an `Error`.
Note, that because we changed the output of the error in `main()` from
`Debug` to `Display`, we don't see the error backtrace with filename and line number.
To enable the `Display` backtrace, you have to enable the feature `display-cause` for `chainerror`.
To use the `Display` backtrace, you have to use the alternative display format output `{:#}`.

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@ -4,15 +4,15 @@
~~~rust,ignore
fn is_chain<T: 'static + Display + Debug>(&self) -> bool
fn downcast_chain_ref<T: 'static + Display + Debug>(&self) -> Option<&ChainError<T>>
fn downcast_chain_mut<T: 'static + Display + Debug>(&mut self) -> Option<&mut ChainError<T>>
fn downcast_chain_ref<T: 'static + Display + Debug>(&self) -> Option<&chainerror::Error<T>>
fn downcast_chain_mut<T: 'static + Display + Debug>(&mut self) -> Option<&mut chainerror::Error<T>>
fn root_cause(&self) -> Option<&(dyn Error + 'static)>
fn find_cause<U: Error + 'static>(&self) -> Option<&U>
fn find_chain_cause<U: Error + 'static>(&self) -> Option<&ChainError<U>>
fn find_chain_cause<U: Error + 'static>(&self) -> Option<&chainerror::Error<U>>
fn kind<'a>(&'a self) -> &'a T
~~~
Using `downcast_chain_ref::<String>()` gives a `ChainError<String>`, which can be used
Using `downcast_chain_ref::<String>()` gives a `chainerror::Error<String>`, which can be used
to call `.find_cause::<io::Error>()`.
~~~rust,ignore

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@ -1,14 +1,14 @@
# Finding an Error cause
To distinguish the errors occuring in various places, we can define named string errors with the
To distinguish the errors occurring in various places, we can define named string errors with the
"new type" pattern.
~~~rust,ignore
derive_str_context!(Func2Error);
derive_str_context!(Func1Error);
chainerror::str_context!(Func2Error);
chainerror::str_context!(Func1Error);
~~~
Instead of `ChainError<String>` we now have `struct Func1Error(String)` and `ChainError<Func1Error>`.
Instead of `chainerror::Error<String>` we now have `struct Func1Error(String)` and `chainerror::Error<Func1Error>`.
In the `main` function you can see, how we can match the different errors.
@ -18,9 +18,9 @@ Also see:
~~~
as a shortcut to
~~~rust,ignore
if let Some(f2err) = f1err.find_cause::<ChainError<Func2Error>>() {
if let Some(f2err) = f1err.find_cause::<chainerror::Error<Func2Error>>() {
~~~
hiding the `ChainError<T>` implementation detail.
hiding the `chainerror::Error<T>` implementation detail.
~~~rust
{{#include ../examples/tutorial8.rs}}

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@ -1,24 +1,28 @@
use chainerror::Context as _;
use std::error::Error;
use std::fmt;
use std::io;
use std::result::Result;
use chainerror::prelude::v1::*;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
fn func3() -> Result<(), Box<dyn Error + Send + Sync>> {
fn func4() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
do_some_io().context(format!("Error reading '{}'", filename))?;
Ok(())
}
derive_str_context!(Func2Error);
fn func3() -> Result<(), Box<dyn Error + Send + Sync>> {
func4().annotate()?;
Ok(())
}
fn func2() -> ChainResult<(), Func2Error> {
func3().context(Func2Error("func2 error: calling func3".to_string()))?;
chainerror::str_context!(Func2Error);
fn func2() -> chainerror::Result<(), Func2Error> {
func3().context(Func2Error::new("func2 error: calling func3"))?;
Ok(())
}
@ -27,8 +31,8 @@ enum Func1Error {
IO(String),
}
impl ::std::fmt::Display for Func1Error {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
impl fmt::Display for Func1Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Func1Error::Func2 => write!(f, "func1 error calling func2"),
Func1Error::IO(filename) => write!(f, "Error reading '{}'", filename),
@ -36,13 +40,13 @@ impl ::std::fmt::Display for Func1Error {
}
}
impl ::std::fmt::Debug for Func1Error {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
impl fmt::Debug for Func1Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self)
}
}
fn func1() -> ChainResult<(), Func1Error> {
fn func1() -> chainerror::Result<(), Func1Error> {
func2().context(Func1Error::Func2)?;
let filename = String::from("bar.txt");
do_some_io().context(Func1Error::IO(filename))?;

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@ -3,7 +3,6 @@
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,14 +1,14 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
@ -32,7 +32,7 @@ impl ::std::fmt::Display for Func1ErrorKind {
}
impl ::std::error::Error for Func1ErrorKind {}
fn func1() -> ChainResult<(), Func1ErrorKind> {
fn func1() -> chainerror::Result<(), Func1ErrorKind> {
func2().context(Func1ErrorKind::Func2)?;
let filename = String::from("bar.txt");
do_some_io().context(Func1ErrorKind::IO(filename))?;

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@ -1,14 +1,14 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
@ -38,7 +38,7 @@ impl ::std::fmt::Debug for Func1ErrorKind {
impl ::std::error::Error for Func1ErrorKind {}
fn func1() -> ChainResult<(), Func1ErrorKind> {
fn func1() -> chainerror::Result<(), Func1ErrorKind> {
func2().context(Func1ErrorKind::Func2)?;
let filename = String::from("bar.txt");
do_some_io().context(Func1ErrorKind::IO(filename))?;

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@ -1,14 +1,14 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
@ -38,7 +38,7 @@ impl ::std::fmt::Debug for Func1ErrorKind {
impl ::std::error::Error for Func1ErrorKind {}
fn func1() -> ChainResult<(), Func1ErrorKind> {
fn func1() -> chainerror::Result<(), Func1ErrorKind> {
func2().context(Func1ErrorKind::Func2)?;
let filename = String::from("bar.txt");
do_some_io().context(Func1ErrorKind::IO(filename))?;

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@ -2,7 +2,8 @@
#![allow(clippy::redundant_pattern_matching)]
pub mod mycrate {
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::io;
fn do_some_io() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
@ -10,7 +11,7 @@ pub mod mycrate {
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
let filename = "foo.txt";
@ -24,7 +25,7 @@ pub mod mycrate {
IO(String),
}
derive_err_kind!(Error, ErrorKind);
chainerror::err_kind!(Error, ErrorKind);
pub type Result<T> = std::result::Result<T, Error>;

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@ -2,7 +2,8 @@
#![allow(clippy::redundant_pattern_matching)]
pub mod mycrate {
use chainerror::prelude::v1::*;
use chainerror::{Context as _, ErrorDown as _};
use std::io;
fn do_some_io(_f: &str) -> std::result::Result<(), io::Error> {
@ -10,7 +11,7 @@ pub mod mycrate {
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
let filename = "foo.txt";
@ -26,7 +27,7 @@ pub mod mycrate {
Unknown,
}
derive_err_kind!(Error, ErrorKind);
chainerror::err_kind!(Error, ErrorKind);
pub type Result<T> = std::result::Result<T, Error>;
impl std::fmt::Display for ErrorKind {

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@ -1,8 +1,7 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,8 +1,7 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,7 +1,7 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,7 +1,7 @@
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,10 +1,10 @@
#![allow(clippy::single_match)]
#![allow(clippy::redundant_pattern_matching)]
use chainerror::prelude::v1::*;
use chainerror::Context as _;
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,10 +1,10 @@
#![allow(clippy::single_match)]
#![allow(clippy::redundant_pattern_matching)]
use chainerror::prelude::v1::*;
use chainerror::{Context as _, ErrorDown as _};
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;

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@ -1,14 +1,14 @@
use chainerror::prelude::v1::*;
use chainerror::{Context as _, ErrorDown as _};
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
@ -16,10 +16,10 @@ fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
Ok(())
}
derive_str_context!(Func1Error);
chainerror::str_context!(Func1Error);
fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
func2().context(Func1Error("func1 error".to_string()))?;
func2().context(Func1Error::new("func1 error"))?;
Ok(())
}
@ -28,7 +28,7 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
if let Some(f1err) = e.downcast_chain_ref::<Func1Error>() {
eprintln!("Func1Error: {}", f1err);
if let Some(f2err) = f1err.find_cause::<ChainError<Func2Error>>() {
if let Some(f2err) = f1err.find_cause::<chainerror::Error<Func2Error>>() {
eprintln!("Func2Error: {}", f2err);
}

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@ -1,14 +1,14 @@
use chainerror::prelude::v1::*;
use chainerror::{Context as _, ErrorDown};
use std::error::Error;
use std::io;
use std::result::Result;
fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
Err(io::Error::from(io::ErrorKind::NotFound))?;
Ok(())
}
derive_str_context!(Func2Error);
chainerror::str_context!(Func2Error);
fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
let filename = "foo.txt";
@ -16,11 +16,11 @@ fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
Ok(())
}
derive_str_context!(Func1ErrorFunc2);
derive_str_context!(Func1ErrorIO);
chainerror::str_context!(Func1ErrorFunc2);
chainerror::str_context!(Func1ErrorIO);
fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
func2().context(Func1ErrorFunc2("func1 error calling func2".to_string()))?;
func2().context(Func1ErrorFunc2::new("func1 error calling func2"))?;
let filename = "bar.txt";
do_some_io().context(Func1ErrorIO(format!("Error reading '{}'", filename)))?;
Ok(())
@ -28,7 +28,7 @@ fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
if let Err(e) = func1() {
if let Some(s) = e.downcast_ref::<ChainError<Func1ErrorIO>>() {
if let Some(s) = e.downcast_ref::<chainerror::Error<Func1ErrorIO>>() {
eprintln!("Func1ErrorIO:\n{:?}", s);
}

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@ -8,18 +8,6 @@ use std::error::Error as StdError;
use std::fmt::{Debug, Display, Formatter};
use std::panic::Location;
pub mod prelude {
//! convenience prelude
pub mod v1 {
//! convenience prelude
pub use super::super::ChainErrorDown as _;
pub use super::super::Error as ChainError;
pub use super::super::Result as ChainResult;
pub use super::super::ResultTrait as _;
pub use crate::{derive_err_kind, derive_str_context};
}
}
/// chains an inner error kind `T` with a causing error
pub struct Error<T> {
occurrence: Option<String>,
@ -55,7 +43,8 @@ impl<T: 'static + Display + Debug> Error<T> {
/// # Examples
///
/// ```rust
/// use chainerror::prelude::v1::*;
/// use chainerror::Context as _;
/// use chainerror::ErrorDown as _;
/// use std::error::Error;
/// use std::io;
///
@ -64,7 +53,7 @@ impl<T: 'static + Display + Debug> Error<T> {
/// Ok(())
/// }
///
/// derive_str_context!(Func2Error);
/// chainerror::str_context!(Func2Error);
///
/// fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
/// let filename = "foo.txt";
@ -72,10 +61,10 @@ impl<T: 'static + Display + Debug> Error<T> {
/// Ok(())
/// }
///
/// derive_str_context!(Func1Error);
/// chainerror::str_context!(Func1Error);
///
/// fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
/// func2().context(Func1Error("func1 error".into()))?;
/// func2().context(Func1Error::new("func1 error"))?;
/// Ok(())
/// }
///
@ -107,13 +96,12 @@ impl<T: 'static + Display + Debug> Error<T> {
/// # Examples
///
/// ```rust
/// # use chainerror::prelude::v1::*;
/// # derive_str_context!(FooError);
/// # let err = ChainError::new(String::new(), None, None);
/// # chainerror::str_context!(FooError);
/// # let err = chainerror::Error::new(String::new(), None, None);
/// // Instead of writing
/// err.find_cause::<ChainError<FooError>>();
/// err.find_cause::<chainerror::Error<FooError>>();
///
/// // leave out the ChainError<FooError> implementation detail
/// // leave out the chainerror::Error<FooError> implementation detail
/// err.find_chain_cause::<FooError>();
/// ```
#[inline]
@ -130,17 +118,16 @@ impl<T: 'static + Display + Debug> Error<T> {
/// # Examples
///
/// ```rust
/// # use chainerror::prelude::v1::*;
/// # derive_str_context!(FooErrorKind);
/// # let err = ChainError::new(String::new(), None, None);
/// # chainerror::str_context!(FooErrorKind);
/// # let err = chainerror::Error::new(String::new(), None, None);
/// // Instead of writing
/// err.find_cause::<ChainError<FooErrorKind>>();
/// err.find_cause::<chainerror::Error<FooErrorKind>>();
/// // and/or
/// err.find_chain_cause::<FooErrorKind>();
/// // and/or
/// err.find_cause::<FooErrorKind>();
///
/// // leave out the ChainError<FooErrorKind> implementation detail
/// // leave out the chainerror::Error<FooErrorKind> implementation detail
/// err.find_kind_or_cause::<FooErrorKind>();
/// ```
#[inline]
@ -159,7 +146,7 @@ impl<T: 'static + Display + Debug> Error<T> {
/// # Examples
///
/// ```rust
/// use chainerror::prelude::v1::*;
/// use chainerror::Context as _;
/// use std::error::Error;
/// use std::io;
///
@ -168,7 +155,7 @@ impl<T: 'static + Display + Debug> Error<T> {
/// Ok(())
/// }
///
/// derive_str_context!(Func2Error);
/// chainerror::str_context!(Func2Error);
///
/// fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
/// let filename = "foo.txt";
@ -192,7 +179,7 @@ impl<T: 'static + Display + Debug> Error<T> {
/// # }
/// # }
///
/// fn func1() -> ChainResult<(), Func1ErrorKind> {
/// fn func1() -> chainerror::Result<(), Func1ErrorKind> {
/// func2().context(Func1ErrorKind::Func2)?;
/// do_some_io().context(Func1ErrorKind::IO("bar.txt".into()))?;
/// Ok(())
@ -225,10 +212,13 @@ impl<T: 'static + Display + Debug> Error<T> {
}
/// Convenience methods for `Result<>` to turn the error into a decorated [`Error`](Error)
pub trait ResultTrait<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> {
pub trait Context<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> {
/// Decorate the error with a `kind` of type `T` and the source `Location`
fn context<T: 'static + Display + Debug>(self, kind: T) -> std::result::Result<O, Error<T>>;
/// Decorate the error just with the source `Location`
fn annotate(self) -> std::result::Result<O, Error<AnnotatedError>>;
/// Decorate the `error` with a `kind` of type `T` produced with a `FnOnce(&error)` and the source `Location`
fn map_context<T: 'static + Display + Debug, F: FnOnce(&E) -> T>(
self,
@ -236,7 +226,22 @@ pub trait ResultTrait<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> {
) -> std::result::Result<O, Error<T>>;
}
impl<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> ResultTrait<O, E>
/// Convenience type to just decorate the error with the source `Location`
pub struct AnnotatedError(());
impl Display for AnnotatedError {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "(passed error)")
}
}
impl Debug for AnnotatedError {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "(passed error)")
}
}
impl<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> Context<O, E>
for std::result::Result<O, E>
{
#[track_caller]
@ -252,6 +257,19 @@ impl<O, E: Into<Box<dyn StdError + 'static + Send + Sync>>> ResultTrait<O, E>
}
}
#[track_caller]
#[inline]
fn annotate(self) -> std::result::Result<O, Error<AnnotatedError>> {
match self {
Ok(t) => Ok(t),
Err(error_cause) => Err(Error::new(
AnnotatedError(()),
Some(error_cause.into()),
Some(Location::caller().to_string()),
)),
}
}
#[track_caller]
#[inline]
fn map_context<T: 'static + Display + Debug, F: FnOnce(&E) -> T>(
@ -298,7 +316,7 @@ impl<T: 'static + Display + Debug> std::ops::Deref for Error<T> {
}
/// Convenience trait to hide the [`Error<T>`](Error) implementation internals
pub trait ChainErrorDown {
pub trait ErrorDown {
/// Test if of type `Error<T>`
fn is_chain<T: 'static + Display + Debug>(&self) -> bool;
/// Downcast to a reference of `Error<T>`
@ -311,7 +329,7 @@ pub trait ChainErrorDown {
fn downcast_inner_mut<T: 'static + StdError>(&mut self) -> Option<&mut T>;
}
impl<U: 'static + Display + Debug> ChainErrorDown for Error<U> {
impl<U: 'static + Display + Debug> ErrorDown for Error<U> {
#[inline]
fn is_chain<T: 'static + Display + Debug>(&self) -> bool {
TypeId::of::<T>() == TypeId::of::<U>()
@ -369,7 +387,7 @@ impl<U: 'static + Display + Debug> ChainErrorDown for Error<U> {
}
}
impl ChainErrorDown for dyn StdError + 'static {
impl ErrorDown for dyn StdError + 'static {
#[inline]
fn is_chain<T: 'static + Display + Debug>(&self) -> bool {
self.is::<Error<T>>()
@ -402,7 +420,7 @@ impl ChainErrorDown for dyn StdError + 'static {
}
}
impl ChainErrorDown for dyn StdError + 'static + Send {
impl ErrorDown for dyn StdError + 'static + Send {
#[inline]
fn is_chain<T: 'static + Display + Debug>(&self) -> bool {
self.is::<Error<T>>()
@ -435,7 +453,7 @@ impl ChainErrorDown for dyn StdError + 'static + Send {
}
}
impl ChainErrorDown for dyn StdError + 'static + Send + Sync {
impl ErrorDown for dyn StdError + 'static + Send + Sync {
#[inline]
fn is_chain<T: 'static + Display + Debug>(&self) -> bool {
self.is::<Error<T>>()
@ -549,7 +567,8 @@ where
/// # Examples
///
/// ```rust
/// # use chainerror::prelude::v1::*;
/// # use chainerror::Context as _;
/// # use chainerror::ErrorDown as _;
/// # use std::error::Error;
/// # use std::io;
/// # use std::result::Result;
@ -557,23 +576,23 @@ where
/// # Err(io::Error::from(io::ErrorKind::NotFound))?;
/// # Ok(())
/// # }
/// derive_str_context!(Func2Error);
/// chainerror::str_context!(Func2Error);
///
/// fn func2() -> ChainResult<(), Func2Error> {
/// fn func2() -> chainerror::Result<(), Func2Error> {
/// let filename = "foo.txt";
/// do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
/// Ok(())
/// }
///
/// derive_str_context!(Func1Error);
/// chainerror::str_context!(Func1Error);
///
/// fn func1() -> Result<(), Box<dyn Error>> {
/// func2().context(Func1Error("func1 error".into()))?;
/// func2().context(Func1Error::new("func1 error"))?;
/// Ok(())
/// }
/// # if let Err(e) = func1() {
/// # if let Some(f1err) = e.downcast_chain_ref::<Func1Error>() {
/// # assert!(f1err.find_cause::<ChainError<Func2Error>>().is_some());
/// # assert!(f1err.find_cause::<chainerror::Error<Func2Error>>().is_some());
/// # assert!(f1err.find_chain_cause::<Func2Error>().is_some());
/// # } else {
/// # panic!();
@ -583,10 +602,15 @@ where
/// # }
/// ```
#[macro_export]
macro_rules! derive_str_context {
macro_rules! str_context {
($e:ident) => {
#[derive(Clone)]
pub struct $e(pub String);
impl $e {
pub fn new<S: Into<String>>(s: S) -> Self {
$e(s.into())
}
}
impl ::std::fmt::Display for $e {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
write!(f, "{}", self.0)
@ -612,7 +636,7 @@ macro_rules! derive_str_context {
/// # Examples
///
/// ```rust
/// use chainerror::prelude::v1::*;
/// use chainerror::Context as _;
/// use std::io;
///
/// fn do_some_io(_f: &str) -> std::result::Result<(), io::Error> {
@ -626,7 +650,7 @@ macro_rules! derive_str_context {
/// Unknown,
/// }
///
/// derive_err_kind!(Error, ErrorKind);
/// chainerror::err_kind!(Error, ErrorKind);
///
/// impl std::fmt::Display for ErrorKind {
/// fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
@ -666,7 +690,7 @@ macro_rules! derive_str_context {
/// }
/// ```
#[macro_export]
macro_rules! derive_err_kind {
macro_rules! err_kind {
($e:ident, $k:ident) => {
pub struct $e($crate::Error<$k>);

View file

@ -1,4 +1,4 @@
use chainerror::prelude::v1::*;
use chainerror::Context;
#[test]
fn test_basic() {
@ -19,7 +19,6 @@ fn test_basic() {
if let Err(e) = process_config_file() {
let os_notfound_error = std::io::Error::from_raw_os_error(2);
eprintln!("Error:\n{:?}", e);
let s = format!("{:?}", e);
let lines = s.lines().collect::<Vec<_>>();
assert_eq!(lines.len(), 5);

View file

@ -1,4 +1,4 @@
use chainerror::prelude::v1::*;
use chainerror::Context;
use std::error::Error;
use std::io;