decimal

Arbitrary-precision fixed-point decimal numbers in go.

NOTE: can "only" represent numbers with a maximum of 2^31 digits after the decmial point.

Features

the zero-value is 0, and is safe to use without initialization
addition, subtraction, multiplication with no loss of precision
division with specified precision
database/sql serialization/deserialization
json and xml serialization/deserialization

Install

Run go get github.com/jellolabs/decimal

Usage

package main

import (
    "fmt"
    "github.com/jellolabs/decimal"
)

func main() {
	price, err := decimal.NewFromString("136.02")
    if err != nil {
        panic(err)
    }

	quantity := decimal.NewFromFloat(3)

	fee, _ := decimal.NewFromString(".035")
	taxRate, _ := decimal.NewFromString(".08875")

    subtotal := price.Mul(quantity)

    preTax := subtotal.Mul(fee.Add(decimal.NewFromFloat(1)))

    total := preTax.Mul(taxRate.Add(decimal.NewFromFloat(1)))

	fmt.Println("Subtotal:", subtotal)
	fmt.Println("Pre-tax:", preTax)
    fmt.Println("Taxes:", total.Sub(preTax))
	fmt.Println("Total:", total)
	fmt.Println("Tax rate:", total.Sub(preTax).Div(preTax))
}

Documentation

http://godoc.org/github.com/jellolabs/decimal

Production Usage

Spring, since August 14, 2014.
If you are using this in production, please let us know!

License

The MIT License (MIT)

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