Crate koruma 

koruma

koruma is a per-field validation framework focused on:

1. Type Safety: Strongly typed validation error structs generated at compile time.
2. Ergonomics: Derive macros and validator attributes that minimize boilerplate.
3. Developer Experience: Optional constructors, nested/newtype validation, and fluent/i18n.

koruma-collection

A curated set of validators built on top of koruma, organized by domain: string, format, numeric, collection, and general-purpose validators.

Quick Start

use koruma::{Koruma, Validate, validator};

#[validator]
#[derive(Clone, Debug)]
pub struct RangeValidation<T> {
    pub min: T,
    pub max: T,
    #[koruma(value)]
    pub actual: T,
}

impl<T: PartialOrd + Clone> Validate<T> for RangeValidation<T> {
    fn validate(&self, value: &T) -> bool {
        *value >= self.min && *value <= self.max
    }
}

#[derive(Koruma)]
pub struct User {
    #[koruma(RangeValidation::<_>(min = 0, max = 150))]
    pub age: i32,
}

let user = User { age: 200 };
let err = user.validate().unwrap_err();
if let Some(range_err) = err.age().range_validation() {
    println!("age out of range: {}", range_err.actual);
}

Fluent/i18n

Enable the fluent feature and derive EsFluent on validators for localized messages. Use KorumaAllFluent to format all() results, and koruma-collection with full-fluent to get built-in validators plus translations.

Examples

• collection validators
• user-defined validators

Traits

BuilderWithValue

Trait for validator builders that can receive the value being validated.

NewtypeValidation

Marker trait for newtype structs (single-field wrappers) that derive Koruma.

Validate

Trait for types that can validate a value of type T.

ValidateExt

Trait for structs that derive Koruma and have a validate() method.

ValidationError

Trait for validation error structs that have no errors.

Attribute Macros

validator

Attribute macro for validator structs.

Derive Macros

Koruma

Derive macro for generating validation error structs and validate methods.

KorumaAllDisplay

Derive macro for implementing Display on the all() validator enums.

KorumaAllFluent

Derive macro for implementing ToFluentString on the all() validator enums.