A Decimal implementation written in pure Rust suitable for financial calculations that require significant integral and fractional digits with no round-off errors.
The binary representation consists of a 96 bit integer number, a scaling factor used to specify the decimal fraction and a 1 bit sign. Because of this representation, trailing zeros are preserved and may be exposed when in string form. These can be truncated using the normalize or round_dp functions.
Decimal numbers can be created in a few distinct ways. The easiest and most optimal method of creating a Decimal is to use the procedural macro within the rust_decimal_macros crate:
// Procedural macros need importing directly
use rust_decimal_macros::*;
let number = dec!(-1.23);Alternatively you can also use one of the Decimal number convenience functions:
use rust_decimal::prelude::*;
// Using an integer followed by the decimal points
let scaled = Decimal::new(202, 2); // 2.02
// From a string representation
let from_string = Decimal::from_str("2.02").unwrap(); // 2.02
// Using the `Into` trait
let my_int : Decimal = 3i32.into();
// Using the raw decimal representation
// 3.1415926535897932384626433832
let pi = Decimal::from_parts(1102470952, 185874565, 1703060790, false, 28);This feature enables a PostgreSQL communication module. It allows for reading and writing the Decimal
type by transparently serializing/deserializing into the NUMERIC data type within PostgreSQL.
Enables the tokio postgres module allowing for async communication with PostgreSQL.
Enable this so that JSON serialization of Decimal types are sent as a float instead of a string (default).
e.g. with this turned on, JSON serialization would output:
{
"value": 1.234
}