This commit is contained in:
Harald Hoyer 2018-12-18 16:21:45 +01:00
parent 6066a41f97
commit 8017b6cdfd

View file

@ -1,25 +1,52 @@
pub trait ChainError: ::std::error::Error + Sized {
fn root_cause(&self) -> Option<&(dyn::std::error::Error + 'static)>;
fn new(
line: u32,
filename: &'static str,
description: Option<String>,
error_cause: Option<Box<dyn std::error::Error + 'static>>,
) -> Self;
fn root_cause(&self) -> Option<&(dyn std::error::Error + 'static)>;
fn find_cause<T: ::std::error::Error + 'static>(
&self,
) -> Option<&(dyn::std::error::Error + 'static)>;
) -> Option<&(dyn std::error::Error + 'static)>;
}
pub trait ChainErrorFrom<T>: ChainError {
fn chain_error_from(_: T, _: u32, _: &'static str, _: Option<String>) -> Self;
}
pub trait IntoChainError<T: ChainError>: Sized {
fn into_chain_error(self, line: u32, filename: &'static str, description: Option<String>) -> T;
}
impl<T, U> IntoChainError<U> for T
where
U: ChainErrorFrom<T> + ChainError,
{
fn into_chain_error(self, line: u32, filename: &'static str, description: Option<String>) -> U {
U::chain_error_from(self, line, filename, description)
}
}
#[macro_export]
macro_rules! chain_error {
macro_rules! chain_error_fn {
( $t:ident, $v:expr $(, $more:expr)* ) => {
|e| <$t> :: new(line!(), file!(), format!($v, $( $more , )* ), Some(e.into()))
|e| <$t> :: new(line!(), file!(), Some(format!($v, $( $more , )* )), Some(e.into()))
};
( $t:path, $v:expr $(, $more:expr)* ) => {
|e| <$t> :: new(line!(), file!(), format!($v, $( $more , )* ), Some(e.into()))
|e| <$t> :: new(line!(), file!(), Some(format!($v, $( $more , )* )), Some(e.into()))
};
( $t:ident) => {
|e| <$t> :: new(line!(), file!(), None, Some(e.into()))
};
( $t:path) => {
|e| <$t> :: new(line!(), file!(), None, Some(e.into()))
};
}
#[macro_export]
macro_rules! into_chain_error {
( $v:expr $(, $more:expr)* ) => {
|e| e.into_chain_error(line!(), file!(), Some(format!($v, $( $more , )* )))
};
macro_rules! into_chain_error_fn {
( $v:expr $(, $more:expr)* ) => {
|e| e.into_chain_error(line!(), file!(), Some(format!($v, $( $more , )* )))
};
@ -29,31 +56,52 @@ macro_rules! into_chain_error {
}
#[macro_export]
macro_rules! throw_error {
( $t:ident, $v:expr $(, $more:expr)* ) => {
Err(<$t> :: new(line!(), file!(), format!($v, $( $more , )*), None))
macro_rules! chain_error_from_fn {
( $t:expr, $v:expr $(, $more:expr)* ) => {
|e| ($t).into().chain_error_from(e, line!(), file!(), Some(format!($v, $( $more , )* )))
};
( $t:path, $v:expr $(, $more:expr)* ) => {
Err(<$t> :: new(line!(), file!(), format!($v, $( $more , )*), None))
( $t:expr ) => {
|e| ($t).into().chain_error_from(e, line!(), file!(), None)
};
}
#[macro_export]
macro_rules! new_chain_error {
macro_rules! chain_error {
( $t:ident, $v:expr $(, $more:expr)* ) => {
<$t> :: new(line!(), file!(), Some(format!($v, $( $more , )*)), None)
};
( $t:path, $v:expr $(, $more:expr)* ) => {
<$t> :: new(line!(), file!(), Some(format!($v, $( $more , )*)), None)
};
}
#[macro_export]
macro_rules! into_chain_error {
( $t:expr, $v:expr $(, $more:expr)* ) => {
$t . into_chain_error(line!(), file!(), Some(format!($v, $( $more , )*)))
};
( $t:expr ) => {
$t . into_chain_error(line!(), file!(), None)
};
}
#[macro_export]
macro_rules! derive_chain_error {
($e:ident) => {
pub struct $e {
line: u32,
filename: &'static str,
description: String,
error_cause: Option<Box<dyn::std::error::Error + 'static>>,
description: Option<String>,
error_cause: Option<Box<dyn std::error::Error + 'static>>,
}
impl $e {
pub fn new(
impl ChainError for $e {
fn new(
line: u32,
filename: &'static str,
description: String,
error_cause: Option<Box<dyn::std::error::Error + 'static>>,
description: Option<String>,
error_cause: Option<Box<dyn std::error::Error + 'static>>,
) -> Self {
$e {
line,
@ -62,11 +110,9 @@ macro_rules! new_chain_error {
error_cause,
}
}
}
impl ChainError for $e {
fn root_cause(&self) -> Option<&(dyn::std::error::Error + 'static)> {
let mut cause = self as &(dyn::std::error::Error + 'static);
fn root_cause(&self) -> Option<&(dyn std::error::Error + 'static)> {
let mut cause = self as &(dyn std::error::Error + 'static);
while let Some(c) = cause.source() {
cause = c;
}
@ -75,8 +121,8 @@ macro_rules! new_chain_error {
fn find_cause<T: ::std::error::Error + 'static>(
&self,
) -> Option<&(dyn::std::error::Error + 'static)> {
let mut cause = self as &(dyn::std::error::Error + 'static);
) -> Option<&(dyn std::error::Error + 'static)> {
let mut cause = self as &(dyn std::error::Error + 'static);
loop {
if cause.is::<T>() {
return Some(cause);
@ -92,10 +138,14 @@ macro_rules! new_chain_error {
impl ::std::error::Error for $e {
fn description(&self) -> &str {
&self.description
if let Some(ref d) = self.description {
d.as_ref()
} else {
""
}
}
fn source(&self) -> Option<&(dyn::std::error::Error + 'static)> {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
if let Some(ref e) = self.error_cause {
Some(e.as_ref())
} else {
@ -106,7 +156,7 @@ macro_rules! new_chain_error {
impl ::std::fmt::Display for $e {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
writeln!(f, "{}", self.description)?;
writeln!(f, "{}", self.description())?;
if let Some(e) = self.source() {
writeln!(f, "\nCaused by:")?;
::std::fmt::Display::fmt(&e, f)?;
@ -117,7 +167,13 @@ macro_rules! new_chain_error {
impl ::std::fmt::Debug for $e {
fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
writeln!(f, "\n{}:{}: {}", self.filename, self.line, self.description)?;
writeln!(
f,
"\n{}:{}: {}",
self.filename,
self.line,
self.description()
)?;
if let Some(e) = self.source() {
writeln!(f, "\nCaused by:")?;
::std::fmt::Debug::fmt(&e, f)?;
@ -128,36 +184,25 @@ macro_rules! new_chain_error {
};
}
pub trait FromChainError<T>: Sized {
fn from_chain_error(_: T, _: u32, _: &'static str, _: Option<String>) -> Self;
}
pub trait IntoChainError<T>: Sized {
fn into_chain_error(self, line: u32, filename: &'static str, description: Option<String>) -> T;
}
impl<T, U> IntoChainError<U> for T where U: FromChainError<T>
{
fn into_chain_error(self, line: u32, filename: &'static str, description: Option<String>) -> U {
U::from_chain_error(self, line, filename, description)
}
}
pub mod prelude {
pub use super::{chain_error, new_chain_error, throw_error, ChainError};
pub use super::{
chain_error, chain_error_fn, chain_error_from_fn, derive_chain_error, into_chain_error,
into_chain_error_fn, ChainError, ChainErrorFrom, IntoChainError,
};
}
#[cfg(test)]
mod tests {
use crate::prelude::*;
use std::error::Error;
new_chain_error!(MyError);
new_chain_error!(MyMainError);
use crate::prelude::*;
derive_chain_error!(MyError);
derive_chain_error!(MyMainError);
fn throw_error() -> Result<(), MyError> {
let directory = String::from("ldfhgdfkgjdf");
::std::fs::remove_dir(&directory).map_err(chain_error!(
::std::fs::remove_dir(&directory).map_err(chain_error_fn!(
MyError,
"Could not remove directory '{}'{}",
&directory,
@ -168,7 +213,7 @@ mod tests {
#[test]
fn it_works() -> Result<(), MyMainError> {
let res = throw_error().map_err(chain_error!(MyMainError, "I has an error."));
let res = throw_error().map_err(chain_error_fn!(MyMainError, "I has an error."));
if let Err(my_err) = res {
if let Some(source) = my_err.source() {