Struct Rational 

pub struct Rational { /* private fields */ }

A rational number represented as a fraction (numerator / denominator).

This type is commonly used to represent:

• Time bases (e.g., 1/90000 for MPEG-TS, 1/1000 for milliseconds)
• Frame rates (e.g., 30000/1001 for 29.97 fps)
• Aspect ratios (e.g., 16/9)

Invariants

• Denominator is always positive (sign is in numerator)
• Zero denominator is handled gracefully (returns infinity/NaN for conversions)

Examples

use ff_format::Rational;

// Common time base for MPEG-TS
let time_base = Rational::new(1, 90000);

// 29.97 fps (NTSC)
let fps = Rational::new(30000, 1001);
assert!((fps.as_f64() - 29.97).abs() < 0.01);

// Invert to get frame duration
let frame_duration = fps.invert();
assert_eq!(frame_duration.num(), 1001);
assert_eq!(frame_duration.den(), 30000);

Implementations

impl Rational

pub const fn new(num: i32, den: i32) -> Rational

Creates a new rational number.

The denominator is normalized to always be positive (the sign is moved to the numerator).

Panics

Does not panic. A zero denominator is allowed but will result in infinity or NaN when converted to floating-point.

Examples

use ff_format::Rational;

let r = Rational::new(1, 2);
assert_eq!(r.num(), 1);
assert_eq!(r.den(), 2);

// Negative denominator is normalized
let r = Rational::new(1, -2);
assert_eq!(r.num(), -1);
assert_eq!(r.den(), 2);

pub const fn zero() -> Rational

Creates a rational number representing zero (0/1).

Examples

use ff_format::Rational;

let zero = Rational::zero();
assert_eq!(zero.as_f64(), 0.0);
assert!(zero.is_zero());

pub const fn one() -> Rational

Creates a rational number representing one (1/1).

Examples

use ff_format::Rational;

let one = Rational::one();
assert_eq!(one.as_f64(), 1.0);

pub const fn num(&self) -> i32

Returns the numerator.

Examples

use ff_format::Rational;

let r = Rational::new(3, 4);
assert_eq!(r.num(), 3);

pub const fn den(&self) -> i32

Returns the denominator.

The denominator is always non-negative.

Examples

use ff_format::Rational;

let r = Rational::new(3, 4);
assert_eq!(r.den(), 4);

pub fn as_f64(self) -> f64

Converts the rational number to a floating-point value.

Returns f64::INFINITY, f64::NEG_INFINITY, or f64::NAN for edge cases (division by zero).

Examples

use ff_format::Rational;

let r = Rational::new(1, 4);
assert_eq!(r.as_f64(), 0.25);

let r = Rational::new(1, 3);
assert!((r.as_f64() - 0.333333).abs() < 0.001);

pub fn as_f32(self) -> f32

Converts the rational number to a single-precision floating-point value.

Examples

use ff_format::Rational;

let r = Rational::new(1, 2);
assert_eq!(r.as_f32(), 0.5);

pub const fn invert(self) -> Rational

Returns the inverse (reciprocal) of this rational number.

Examples

use ff_format::Rational;

let r = Rational::new(3, 4);
let inv = r.invert();
assert_eq!(inv.num(), 4);
assert_eq!(inv.den(), 3);

// Negative values
let r = Rational::new(-3, 4);
let inv = r.invert();
assert_eq!(inv.num(), -4);
assert_eq!(inv.den(), 3);

pub const fn is_zero(self) -> bool

Returns true if this rational number is zero.

Examples

use ff_format::Rational;

assert!(Rational::new(0, 1).is_zero());
assert!(Rational::new(0, 100).is_zero());
assert!(!Rational::new(1, 100).is_zero());

pub const fn is_positive(self) -> bool

Returns true if this rational number is positive.

Examples

use ff_format::Rational;

assert!(Rational::new(1, 2).is_positive());
assert!(!Rational::new(-1, 2).is_positive());
assert!(!Rational::new(0, 1).is_positive());

pub const fn is_negative(self) -> bool

Returns true if this rational number is negative.

Examples

use ff_format::Rational;

assert!(Rational::new(-1, 2).is_negative());
assert!(!Rational::new(1, 2).is_negative());
assert!(!Rational::new(0, 1).is_negative());

pub const fn abs(self) -> Rational

Returns the absolute value of this rational number.

Examples

use ff_format::Rational;

assert_eq!(Rational::new(-3, 4).abs(), Rational::new(3, 4));
assert_eq!(Rational::new(3, 4).abs(), Rational::new(3, 4));

pub fn reduce(self) -> Rational

Reduces the rational to its lowest terms using GCD.

Examples

use ff_format::Rational;

let r = Rational::new(4, 8);
let reduced = r.reduce();
assert_eq!(reduced.num(), 1);
assert_eq!(reduced.den(), 2);

Trait Implementations

impl Add for Rational

type Output = Rational

The resulting type after applying the + operator.

fn add(self, rhs: Rational) -> <Rational as Add>::Output

Performs the + operation.

impl Clone for Rational

fn clone(&self) -> Rational

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Rational

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Rational

fn default() -> Rational

Returns the default rational number (1/1).

impl Display for Rational

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Div<i32> for Rational

type Output = Rational

The resulting type after applying the / operator.

fn div(self, rhs: i32) -> <Rational as Div<i32>>::Output

Performs the / operation.

impl Div for Rational

type Output = Rational

The resulting type after applying the / operator.

fn div(self, rhs: Rational) -> <Rational as Div>::Output

Performs the / operation.

impl From<(i32, i32)> for Rational

fn from(_: (i32, i32)) -> Rational

Converts to this type from the input type.

impl From<i32> for Rational

fn from(n: i32) -> Rational

Converts to this type from the input type.

impl Hash for Rational

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Mul<i32> for Rational

type Output = Rational

The resulting type after applying the * operator.

fn mul(self, rhs: i32) -> <Rational as Mul<i32>>::Output

Performs the * operation.

impl Mul for Rational

type Output = Rational

The resulting type after applying the * operator.

fn mul(self, rhs: Rational) -> <Rational as Mul>::Output

Performs the * operation.

impl Neg for Rational

type Output = Rational

The resulting type after applying the - operator.

fn neg(self) -> <Rational as Neg>::Output

Performs the unary - operation.

impl Ord for Rational

fn cmp(&self, other: &Rational) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Rational

fn eq(&self, other: &Rational) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Rational

fn partial_cmp(&self, other: &Rational) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub for Rational

type Output = Rational

The resulting type after applying the - operator.

fn sub(self, rhs: Rational) -> <Rational as Sub>::Output

Performs the - operation.

impl Copy for Rational

impl Eq for Rational