duration-extender

A lightweight, zero-dependency Rust crate that extends primitive integer types with intuitive methods for creating std::time::Duration objects.

Write expressive, human-readable code for timeouts, delays, and schedules without the verbosity of Duration::from_secs().

Why duration-extender?

⚠️ Breaking Changes in v0.2.0

Negative values now panic instead of using absolute value.

Previously in v0.1.0:

(-5).minutes() == 5.minutes() // ❌ Surprising - used abs()

Now in v0.2.0:

5.minutes()    // ✅ Works fine
(-5).minutes() // ❌ Panics: "duration cannot be negative: got -5 minutes"

This change prevents silent bugs. See CHANGELOG.md for details.

Before:

let timeout = Duration::from_secs(30);
let delay = Duration::from_secs(5 * 60);
let cache_ttl = Duration::from_secs(24 * 60 * 60);

After:

let timeout = 30.seconds();
let delay = 5.minutes();
let cache_ttl = 1.days();

Features

Fluent API — Natural, readable syntax for duration creation
Type-safe — Works with u64, u32, i64, and i32
Explicit errors — Uses saturating arithmetic for overflow; panics on negative values with clear messages
Zero dependencies — Just the standard library
Minimal overhead — Compiles down to the same code as manual duration creation

Installation

Add this to your Cargo.toml:

[dependencies]
duration-extender = "0.2"  # ← Change from 0.1

Usage

Import the DurationExt trait to unlock duration methods on integers:

use duration_extender::DurationExt;
use std::time::Duration;

fn main() {
    // Create durations with clear, readable syntax
    let timeout = 10.seconds();
    let delay = 5.minutes();
    let long_wait = 2.days();
    
    // Combine durations naturally
    let total_time = 2.hours() + 30.minutes() + 15.seconds();
    
    // Works with variables
    let retry_count = 3;
    let backoff = retry_count.seconds();
    
    // Signed integers must be non-negative (panics on negative)
    let elapsed = 100.seconds(); // ✅ Works
    // let bad = (-100).seconds(); // ❌ Panics!
}

Real-World Examples

HTTP client timeout:

let client = reqwest::Client::builder()
    .timeout(30.seconds())
    .build()?;

Tokio sleep:

tokio::time::sleep(2.seconds()).await;

Cache expiration:

cache.insert_with_ttl("key", value, 24.hours());

Rate limiting:

let rate_limit = RateLimit::new(100, 1.minutes());

Available Methods

The DurationExt trait provides these methods:

Method	Equivalent
`.seconds()`	`Duration::from_secs(n)`
`.minutes()`	`Duration::from_secs(n * 60)`
`.hours()`	`Duration::from_secs(n * 3600)`
`.days()`	`Duration::from_secs(n * 86400)`
`.weeks()`	`Duration::from_secs(n * 604800)`

Supported Types

The DurationExt trait is implemented for:

u64 and u32 — Direct conversion
i64 and i32 — Panics on negative values to prevent bugs

All operations use saturating arithmetic to prevent overflow panics.

Safety Guarantees

Overflow safe — Saturating arithmetic prevents overflow panics
Negative handling — Signed integers panic on negative values with clear error messages
Type safety — Leverages Rust's type system for compile-time correctness

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is dual-licensed under:

You may choose either license for your purposes.

Acknowledgments

Inspired by duration extension patterns from other languages and the Rust community's focus on ergonomic APIs.

duration-extender 0.2.0