#decimal #financial #fixed #precision

rust_decimal

A Decimal Implementation written in pure Rust suitable for financial calculations

40 releases (5 stable)

✓ Uses Rust 2018 edition

1.1.0 Dec 27, 2019
1.0.3 Aug 23, 2019
1.0.1 Apr 28, 2019
0.11.3 Mar 31, 2019
0.1.0 Nov 16, 2016

#1 in Science

Download history 3979/week @ 2019-10-04 4829/week @ 2019-10-11 5472/week @ 2019-10-18 4986/week @ 2019-10-25 5214/week @ 2019-11-01 5451/week @ 2019-11-08 4616/week @ 2019-11-15 4983/week @ 2019-11-22 5198/week @ 2019-11-29 6871/week @ 2019-12-06 5481/week @ 2019-12-13 3619/week @ 2019-12-20 2907/week @ 2019-12-27 4818/week @ 2020-01-03 5725/week @ 2020-01-10

21,233 downloads per month
Used in 60 crates (24 directly)

MIT license

130KB
2.5K SLoC

Decimal   Build Status Latest Version

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.

Documentation

Usage

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::Decimal;

// 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);

Features

postgres

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.

tokio-pg

Enables the tokio postgres module allowing for async communication with PostgreSQL.

serde-float

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
}

Dependencies

~0.7–2MB
~39K SLoC