range_checker

range_checker is a derive-macro crate aimed to provide declarative bounds checking and filtering for structure.

Examples

use range_checker::Check;

#[derive(Debug, Default, Check)]
struct TestStruct {
    #[range(..=5)]
    #[range(20..)]
    #[filter(|x| x % 2 != 0)]
    #[fallback(255)]
    pub v0: u8,
    #[range(-1.0..=5.0)]
    #[fallback(3.1)]
    v1: f32,
    #[filter(|&x| x > 8.0)]
    #[fallback(9.9)]
    v2: f64,
    #[range(..-1)]
    #[fallback(|x| {println!("test fallback closure."); x - 5})]
    v3: isize,
    #[filter(|x:&str| !x.is_empty())]
    v4: String,
}

fn main() {
    let a = TestStruct::default();

    if let Ok(_) = a.check() {
        todo!{}
    }
}

Features

range

Use #[range(...)] to detemine the range for named struct's field.

Multiple #[range(...)] will combined by ||, which allowed to config any range you need.

filter

Use #[filter(#closure)] to filter for named struct's field, #closure: |#type_of_field| -> bool.

Multiple #[filter(#closure)] will combined by &&.

#[filter(#closure)] will combined with #[range(...)] by &&.

fallback

Active with the fn check_with_callback()

Use #[fallback(#closure|#lit)] to set fallback behavior for named struct's field, #closure: |#type_of_field| -> #type_of_field.

One field brokes it's range or filter with fallback attribute setted, fn check_with_fallback() will return Ok(_).

Check or CheckVerbose

range_checker::Check will return Err(()) immediately any field broke it's range or filter.

range_checker::CheckVerbose will check all fields and return detail information like Err(Vec<Error>) or Ok(Vec<Error>) when all of broken fields has a fallback attribute.

Expand Example

Here(https://github.com/TYPEmber/range_checker/tree/master/examples/expand_code.md) is an Expand Example for

use range_checker::Check;
use range_checker::CheckVerbose;

#[derive(Debug, Default, CheckVerbose)]
struct TestStruct {
    #[range(..=5)]
    #[range(20..)]
    #[filter(|x| x % 2 != 0)]
    #[fallback(255)]
    pub v0: u8,
    #[range(-1.0..=5.0)]
    #[fallback(3.1)]
    v1: f32,
    #[filter(|&x| x > 8.0)]
    #[fallback(9.9)]
    v2: f64,
    #[range(..-1)]
    #[fallback(|x| {println!("test fallback closure."); x - 5})]
    v3: isize,
}