//! Learning how to document and publish my own crate.
//!
//! This is just a library with the basic math operations.

/// Defines math errors you can get when dividing
#[derive(Debug)]
pub enum MathError {
    DivisionByZero,
    ZeroDividedByZero,
}

/// Adds two numbers
/// 
/// # Examples
///
/// ```
/// let result = daniels_basic_math::add(2, 2);
/// assert_eq!(result, 4);
/// ```
pub fn add(left: usize, right: usize) -> usize {
    left + right
}

/// Multiplies two numbers
/// 
/// # Examples
///
/// ```
/// let result = daniels_basic_math::multiply(2, 3);
/// assert_eq!(result, 6);
/// ```
pub fn multiply(left: usize, right: usize) -> usize {
    left * right
}

/// Subtracts two numbers
/// 
/// # Examples
///
/// ```
/// let result = daniels_basic_math::subtract(2, 2);
/// assert_eq!(result, 0);
/// ```
pub fn subtract(left: usize, right: usize) -> usize {
    left - right
}

/// Divides the first argument over the second
///
/// # Errors
///
/// - Passing a zero as the right argument leds to a MathError::DivisionByZero error.
/// - Passing zero as both arguments results in a MathError::ZeroDividedByZero error.
/// 
/// # Examples
///
/// ```
/// let result = daniels_basic_math::divide(2, 2);
/// assert!(matches!(result, Ok(1)));
///
/// let result = daniels_basic_math::divide(2, 0);
/// assert!(matches!(result, Err(daniels_basic_math::MathError::DivisionByZero)));
///
/// let result = daniels_basic_math::divide(0, 0);
/// assert!(matches!(result, Err(daniels_basic_math::MathError::ZeroDividedByZero)));
/// ```
pub fn divide(left: usize, right: usize) -> Result<usize, MathError> {
    if left!=0 && right==0 {
        return Err(MathError::DivisionByZero);
    }
    if left==0 && right==0 {
        return Err(MathError::ZeroDividedByZero);
    }
    Ok(left/right)
}