Natural Cron ⏰ (Rust)

Natural Cron is an easy-to-use Rust library for building and validating cron expressions with a clean, human-readable API.

✨ Features

• ✅ Chainable builder methods for constructing cron expressions.
• ✅ Validation for all cron components (minute, hour, day of month, month, day of week).
• ✅ Helpful error messages for invalid inputs.
• ✅ Strong typing using Rust enums and strict validation.
• ✅ No dependencies — lightweight and efficient.

📦 Installation

Add natural-cron to your Cargo.toml:

[dependencies]
natural-cron = "0.1"

Then in your code:

use natural_cron::CronExpressionBuilder;
use natural_cron::CronTimeUnit;

🚀 Usage

Use CronExpressionBuilder to create cron expressions easily:

use natural_cron::CronExpressionBuilder;

fn main() {
    let cron = CronExpressionBuilder::new()
        .at_time("08:00")
        .and_then(|s| s.on_week_days(vec![1, 2, 3, 4, 5]))
        .and_then(|s| Ok(s.compile()));

    match cron {
        Ok(cron_string) => println!("Generated cron: {}", cron_string),
        Err(e) => eprintln!("Failed to generate cron: {}", e),
    }
}

or simle chaining

use natural_cron::CronExpressionBuilder;

fn build_cron() -> Result<String, String> {
    let builder = CronExpressionBuilder::new()
        .at_time("08:00")?
        .on_week_days(vec![1, 2, 3, 4, 5])?;
    Ok(builder.compile())
}

fn main() {
    match build_cron() {
        Ok(cron_string) => println!("Generated cron: {}", cron_string),
        Err(e) => eprintln!("Failed to generate cron: {}", e),
    }
}

📋 Examples Table

📚 API Reference

CronExpressionBuilder Methods

CronTimeUnit Enum

pub enum CronTimeUnit {
    Minute,
    Hour,
    DayOfMonth,
    Month,
    DayOfWeek,
}

🛠 Validators

Behind the scenes, CronValidators ensures your fields are valid:

• validate_minute(i32)
• validate_hour(i32)
• validate_day_of_month(i32)
• validate_month(i32)
• validate_day_of_week(i32)
• validate_time(&str)

🤝 Contributing

Contributions are very welcome! Feel free to open issues or pull requests to improve this library.

📜 License

This project is licensed under the MIT License.

🚀 Quick Start Example

use natural_cron::CronExpressionBuilder;

fn main() {
    let cron = CronExpressionBuilder::new()
        .at_time("08:00")
        .and_then(|s| s.on_week_days(vec![1, 2, 3, 4, 5]))
        .and_then(|s| Ok(s.compile()));

    match cron {
        Ok(cron_string) => println!("Generated cron: {}", cron_string),
        Err(e) => eprintln!("Failed to generate cron: {}", e),
    }
}