Fraction

Lossless fractions and decimals; drop-in float replacement

Features

• Drop in replacement for floats with the exception for NaN == NaN so that it's hashable
• It's hashable, so may be used as values in Sets and keys in dictionaries and hash maps
• Fraction type, representing floats as fractions
• Decimal type, based on Fraction type, represents floats as decimals
• DynaInt implements dynamically growing integer type that performs checked math and avoids stack overflows
• PostgreSQL integration for Numeric/Decimal type (with no extra memory allocations)
• Juniper integration for both fractions and decimals
• Generic integer conversions, such as i8 -> u8, usize -> u8 and so on
• Lossless division with no allocations and infinite precision

Documentation

Here:

Examples

Formatting

```rust use fraction::Fraction;

let fraction = Fraction::new(7, 4);

asserteq!("7/4", format!("{}", fraction)); asserteq!("1.75", format!("{:.2}", fraction)); assert_eq!("1.750", format!("{:#.3}", fraction)); ```

Simple arithmetic

```rust use fraction::Fraction;

fn main () { let mut fr = Fraction::zero ();

fr = fr + Fraction::from (2); // 0 + 2 = 2 fr = fr / Fraction::from (0.5); // 2 / 0.5 = 4

asserteq! (fr, Fraction::from (4)); asserteq! (4.0f64, fr.to_f64 ()); } ```

Decimal

```rust type D = fraction::Decimal;

let result = D::from(0.5) / D::from(0.3); assert_eq!(format!("{:.4}", result), "1.6666"); ```

Using as keys for a HashMap

```rust use std::collections::HashMap; use fraction::Fraction;

fn main () { let f = Fraction::from (0.75);

let mut map: HashMap

map.insert (f, ());

assert! (map.containskey (&Fraction::new (3u64, 4u64))); // 0.75 == 3/4 assert! (map.containskey (&Fraction::new (6u64, 8u64))); // 0.75 == 6/8 assert! (map.containskey (&Fraction::new (12u64, 16u64))); // 0.75 == 12/16 assert! (! map.containskey (&Fraction::from (0.5))); // 0.75 != 1/2 } ```

Generic integer conversion

```rust use fraction::{Sign, GenericFraction};

type F = GenericFraction;

let fra = F::newgeneric(Sign::Plus, 1i8, 42usize).unwrap(); asserteq!(fra, F::new(1u32, 42u32)); ```

Comparison

```rust use fraction::Fraction;

fn main () { let f14 = Fraction::new (1u64, 4u64); // 1/4 == 0.25 let f12 = Fraction::new (1u64, 2u64); // 1/2 == 0.50 let f24 = Fraction::new (2u64, 4u64); // 2/4 == 0.50 let f34 = Fraction::new (3u64, 4u64); // 3/4 == 0.75

asserteq! (f12, f24); // 1/2 == 2/4 asserteq! (f34, f12 + f14); // 3/4 == 1/2 + 1/4 assert_eq! (f14, Fraction::from (0.25)); // 1/4 == 0.25 } ```

Change Log

Look into the CHANGELOG.md file for details