Debug Helper
====================
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This crate provides declarative macros to help you implement the `Debug` trait manually.
Instead of this crate, in most cases, you can use the [`educe`](https://crates.io/crates/educe) crate to implement the `Debug` trait.
## Examples
For structs,
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A {
pub f1: u8,
pub f2: i16,
pub f3: f64,
}
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_struct!(A, f, self, .f1, (.f3, "{:.3}", self.f3));
}
}
let a = A {
f1: 1,
f2: 2,
f3: std::f64::consts::PI,
};
println!("{:#?}", a);
/*
A {
f1: 1,
f3: 3.142,
}
*/
```
For tuple structs,
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A(pub u8, pub i16, pub f64);
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_tuple_struct!(A, f, self, .0, (.2, "{:.3}", self.2));
}
}
let a = A(1, 2, std::f64::consts::PI);
println!("{:#?}", a);
/*
A(
1,
3.142,
)
*/
```
For enums (without the enum name),
```rust
use std::fmt::{self, Formatter, Debug};
pub enum A {
V1,
V2(u8, i16, f64),
V3 {
f1: u8,
f2: i16,
f3: f64,
},
}
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_enum!(A::{V1, (V2(f1, _, f3): (.f1, (.f3, "{:.3}", f3))), {V3{f1, f2: _, f3}: (.f1, (.f3, "{:.3}", f3))}}, f, self);
}
}
let a = A::V1;
let b = A::V2(1, 2, std::f64::consts::PI);
let c = A::V3{
f1: 1,
f2: 2,
f3: std::f64::consts::PI,
};
println!("{:#?}", a);
println!("{:#?}", b);
println!("{:#?}", c);
/*
V1
V2(
1,
3.142,
)
V3 {
f1: 1,
f3: 3.142,
}
*/
```
For enums (with the enum name),
```rust
use std::fmt::{self, Formatter, Debug};
pub enum A {
V1,
V2(u8, i16, f64),
V3 {
f1: u8,
f2: i16,
f3: f64,
},
}
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_enum!({A::V1, (V2(f1, _, f3): (.f1, (.f3, "{:.3}", f3))), {V3{f1, f2: _, f3}: (.f1, (.f3, "{:.3}", f3))}}, f, self);
}
}
let a = A::V1;
let b = A::V2(1, 2, std::f64::consts::PI);
let c = A::V3{
f1: 1,
f2: 2,
f3: std::f64::consts::PI,
};
println!("{:#?}", a);
println!("{:#?}", b);
println!("{:#?}", c);
/*
A::V1
A::V2(
1,
3.142,
)
A::V3 {
f1: 1,
f3: 3.142,
}
*/
```
Ghost fields,
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A {
pub f1: u8,
pub f2: i16,
pub f3: f64,
}
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_struct!(A, f, self, .f1, (.f3, "{:.3}", self.f3), (.sum, "{:.3}", self.f1 as f64 + self.f2 as f64 + self.f3));
}
}
let a = A {
f1: 1,
f2: 2,
f3: std::f64::consts::PI,
};
println!("{:#?}", a);
/*
A {
f1: 1,
f3: 3.142,
sum: 6.142,
}
*/
```
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A(pub u8, pub i16, pub f64);
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_tuple_struct!(A, f, self, .0, (.2, "{:.3}", self.2), (.3, "{:.3}", self.0 as f64 + self.1 as f64 + self.2));
}
}
let a = A(1, 2, std::f64::consts::PI);
println!("{:#?}", a);
/*
A(
1,
3.142,
6.142,
)
*/
```
Fake structs,
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A(pub u8, pub i16, pub f64);
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_struct!(A, f, self, let .f1 = self.0, let .f2 = self.1, let .f3 = self.2);
}
}
let a = A(1, 2, std::f64::consts::PI);
println!("{:#?}", a);
/*
A {
f1: 1,
f2: 2,
f3: 3.141592653589793,
}
*/
```
Fake tuple structs,
```rust
use std::fmt::{self, Formatter, Debug};
pub struct A {
pub f1: u8,
pub f2: i16,
pub f3: f64,
}
impl Debug for A {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
debug_helper::impl_debug_for_tuple_struct!(A, f, self, let .0 = self.f1, let .1 = self.f2, let .2 = self.f3);
}
}
let a = A {
f1: 1,
f2: 2,
f3: std::f64::consts::PI,
};
println!("{:#?}", a);
/*
A(
1,
2,
3.141592653589793,
)
*/
```
## TODO
1. Fake enum struct variants and tuple variants.
1. Enum variants can be renamed.
## Crates.io
https://crates.io/crates/debug-helper
## Documentation
https://docs.rs/debug-helper
## License
[MIT](LICENSE)