Module ppm 

Ppm - parts per million newtype for proportional fee rates. A “parts per million” (ppm) newtype for proportional fee rates.

PPM values represent a proportion where 1_000_000 ppm = 100%. Valid range: 0 to 1_000_000 inclusive.

Calculating fees

Multiply an Amount by a Ppm to get the fee:

let amount = Amount::from_sats_u32(100_000);
let fee_rate = Ppm::new(3000); // 0.3%
let fee = amount * fee_rate;
assert_eq!(fee, Amount::from_sats_u32(300));

Defining constants

Use the ppm! macro for convenient compile-time validated constants:

const A_FEE_RATE_PPM: Ppm = ppm!(3000); // 0.3%
const B_FEE_RATE_PPM: Ppm = ppm!(0.3%); // 0.3%
const C_FEE_RATE_DEC: Decimal = ppm!(3000).to_decimal(); // 0.3%

Converting to a decimal rate or percentage

Ppm::to_decimal returns a Decimal rate, while Ppm::to_percent returns a percentage:

let ppm = ppm!(5000);
assert_eq!(ppm.to_decimal(), dec!(0.005));
assert_eq!(ppm.to_percent(), dec!(0.5));

Structs

Ppm

A “parts per million” value for proportional fee rates.

Enums

Error

Errors that can occur when constructing a Ppm.