# lazyrand for Rust

This is a library for generating random numbers easily. The random seed is automatically initialized. This crate supports WASM.

This library can be used for various purposes such as games and dice. However, this library is not cryptographically secure.

It uses xoshiro256++ for random number generation.

- [crates.io](https://crates.io/crates/lazyrand)
- [docs.rs](https://docs.rs/lazyrand)

## Install

Run the following command in your terminal:

```sh
cargo add lazyrand
```

## Examples

Generate random number

```rust
let num = lazyrand::randint(1, 6);
println!("random number = {}", num);
```

Generate random number with seed.
It can be used to generate the same random number sequence.

```rust
lazyrand::set_seed(123456);
let n1 = lazyrand::rand() % 6 + 1;
let n2 = lazyrand::rand() % 6 + 1;
let n3 = lazyrand::rand() % 6 + 1;
println!("nums = [{}, {}, {}]", n1, n2, n3);
```

## Examples - Slice

Shuffle slice

```rust
let mut a = vec![1, 2, 3, 4, 5];
lazyrand::shuffle(&mut a);
println!("shuffled = {:?}", a); // (ex) shuffled = [2, 4, 1, 5, 3]
```

choice one number from slice

```rust
let a = vec![1, 2, 3];
let n = lazyrand::choice(&a);
println!("choice = {:?}", n); // (ex) choice = Some(5)
```

choice one &str from slice

```rust
let mut a = vec!["apple", "banana", "orange"];
let s = lazyrand::choice(&a).unwrap();
println!("choice = {}", s); // (ex) choice = orange
```

## Examples with Random struct

Generate random number with Random struct

```rust
use lazyrand::Random;
fn main() {
    // Create Random generator
    let mut random = Random::new();
    println!("random number = {}", random.randint(1, 6));

    let msg: &str = random.choice(&["hello", "hi", "bye"]).unwrap();
    println!("random message = {}", msg);
}
```

## How to Use Lazyrand with WASM

Please see [test_wasm](test_wasm/README.md).

## methods

- set_seed(seed) / srand(seed) / generate_seed()
- randint(min, max)
- shuffle(&mut slice)
- choice(&slice)
- rand() / rand_bool() / rand_usize() / rand_isize() / rand_f64()