Debug Helper

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 crate to implement the Debug trait.

Examples

For structs,

```rust

[macrouse] extern crate debughelper;

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> { impldebugforstruct!(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

[macrouse] extern crate debughelper;

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> { impldebugfortuple_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

[macrouse] extern crate debughelper;

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> { impldebugforenum!(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

[macrouse] extern crate debughelper;

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> { impldebugforenum!({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

[macrouse] extern crate debughelper;

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> { impldebugforstruct!(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

[macrouse] extern crate debughelper;

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> { impldebugfortuple_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

[macrouse] extern crate debughelper;

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> { impldebugforstruct!(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

[macrouse] extern crate debughelper;

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> { impldebugfortuple_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.
2. Enum variants can be renamed.

Crates.io

https://crates.io/crates/debug-helper

Documentation

https://docs.rs/debug-helper

License

MIT