1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
# display-error-chain
<!-- cargo-rdme start -->
A lightweight library for displaying errors and their sources.
A sample output:
```rust
macro_rules! impl_error {
// ...
}
// `TopLevel` is caused by a `MidLevel`.
#[derive(Debug)]
struct TopLevel;
impl_error!(TopLevel, "top level", Some(&MidLevel));
// `MidLevel` is caused by a `LowLevel`.
#[derive(Debug)]
struct MidLevel;
impl_error!(MidLevel, "mid level", Some(&LowLevel));
// `LowLevel` is the cause itself.
#[derive(Debug)]
struct LowLevel;
impl_error!(LowLevel, "low level", None);
// Now let's see how it works:
let formatted = display_error_chain::DisplayErrorChain::new(&TopLevel).to_string();
assert_eq!(
formatted,
"\
top level
Caused by:
-> mid level
-> low level"
);
// Or with `.chain()` helper:
use display_error_chain::ErrorChainExt as _;
let formatted = TopLevel.chain().to_string();
assert_eq!(
formatted,
"\
top level
Caused by:
-> mid level
-> low level"
);
// Or even with `.into_chain()` helper to consume the error.
use display_error_chain::ErrorChainExt as _;
let formatted = TopLevel.into_chain().to_string();
assert_eq!(
formatted,
"\
top level
Caused by:
-> mid level
-> low level"
);
```
<!-- cargo-rdme end -->
License: Apache-2.0/MIT
|
