accounting - money and currency formatting for golang

accounting is a library for money and currency formatting. (inspired by accounting.js)

Quick Start

go get github.com/leekchan/accounting

example.go

package main

import (
    "fmt"
    "math/big"

    "github.com/leekchan/accounting"
)

func main() {
    ac := accounting.Accounting{Symbol: "$", Precision: 2}
    fmt.Println(ac.FormatMoney(123456789.213123))                       // "$123,456,789.21"
    fmt.Println(ac.FormatMoney(12345678))                               // "$12,345,678.00"
    fmt.Println(ac.FormatMoney(big.NewRat(77777777, 3)))                // "$25,925,925.67"
    fmt.Println(ac.FormatMoney(big.NewRat(-77777777, 3)))               // "-$25,925,925.67"
    fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(123456789.213123))) // "$123,456,789.21"

    ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
    fmt.Println(ac.FormatMoney(4999.99))  // "€4.999,99"

    ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
    fmt.Println(ac.FormatMoney(500000)) // "£ 500,000"

    ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
        Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
    fmt.Println(ac.FormatMoney(1000000)) // "GBP 1,000,000"
    fmt.Println(ac.FormatMoney(-5000))   // "GBP (5,000)"
    fmt.Println(ac.FormatMoney(0))       // "GBP --"
}

Caution

Please do not use float64 to count money. Floats can have errors when you perform operations on them. Using big.Rat (< Go 1.5) or big.Float (>= Go 1.5) is highly recommended. (accounting supports float64, but it is just for convenience.)

• FormatMoneyBigFloat(value *big.Float) string
• FormatMoneyBigRat(value *big.Rat) string

Initialization

Accounting struct

type Accounting struct {
    Symbol         string // currency symbol (required)
    Precision      int    // currency precision (decimal places) (optional / default: 0)
    Thousand       string // thousand separator (optional / default: ,)
    Decimal        string // decimal separator (optional / default: .)
    Format         string // simple format string allows control of symbol position (%v = value, %s = symbol) (default: %s%v)
    FormatNegative string // format string for negative values (optional / default: strings.Replace(strings.Replace(accounting.Format, "-", "", -1), "%v", "-%v", -1))
    FormatZero     string // format string for zero values (optional / default: Format)
}

Field	Type	Description	Default	Example
Symbol	string	currency symbol	no default value	$
Precision	int	currency precision (decimal places)	0	2
Thousand	string	thousand separator	,	.
Decimal	string	decimal separator	.	,
Format	string	simple format string allows control of symbol position (%v = value, %s = symbol)	%s%v	%s %v
FormatNegative	string	format string for negative values	strings.Replace(strings.Replace(accounting.Format, "-", "", -1), "%v", "-%v", -1))	%s (%v)
FormatZero	string	format string for zero values	Format	%s --

Examples:

ac := accounting.Accounting{Symbol: "$", Precision: 2}

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
        Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}

FormatMoney(value interface{}) string

FormatMoney is a function for formatting numbers as money values, with customisable currency symbol, precision (decimal places), and thousand/decimal separators.

FormatMoney supports various types of value by runtime reflection. If you don't need runtime type evaluation, please refer to FormatMoneyInt, FormatMoneyBigRat, FormatMoneyBigRat, or FormatMoneyFloat64.

• supported value types : int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64, *big.Rat

Examples:

ac := accounting.Accounting{Symbol: "$", Precision: 2}
fmt.Println(ac.FormatMoney(123456789.213123))         // "$123,456,789.21"
fmt.Println(ac.FormatMoney(12345678))                 // "$12,345,678.00"
fmt.Println(ac.FormatMoney(big.NewRat(77777777, 3)))  // "$25,925,925.67"
fmt.Println(ac.FormatMoney(big.NewRat(-77777777, 3))) // "-$25,925,925.67"

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
fmt.Println(ac.FormatMoney(4999.99))  // "€4.999,99"

ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
fmt.Println(ac.FormatMoney(500000)) // "£ 500,000"

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
    Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
fmt.Println(ac.FormatMoney(1000000)) // "GBP 1,000,000"
fmt.Println(ac.FormatMoney(-5000))   // "GBP (5,000)"
fmt.Println(ac.FormatMoney(0))       // "GBP --"

FormatMoneyBigFloat(value *big.Float) string

(>= Go 1.5)

FormatMoneyBigFloat only supports *big.Float value. It is faster than FormatMoney, because it does not do any runtime type evaluation.

Examples:

ac = accounting.Accounting{Symbol: "$", Precision: 2}
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(123456789.213123))) // "$123,456,789.21"
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(12345678)))         // "$12,345,678.00"

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(4999.99)))  // "€4.999,99"

ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(500000))) // "£ 500,000"

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
    Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(1000000))) // "GBP 1,000,000"
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(-5000)))   // "GBP (5,000)"
fmt.Println(ac.FormatMoneyBigFloat(big.NewFloat(0)))       // "GBP --"

FormatMoneyInt(value int) string

FormatMoneyInt only supports int value. It is faster than FormatMoney, because it does not do any runtime type evaluation.

Examples:

ac = accounting.Accounting{Symbol: "$", Precision: 2}
fmt.Println(ac.FormatMoneyInt(12345678)) // "$12,345,678.00"

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
fmt.Println(ac.FormatMoneyInt(4999))  // "€4.999,00"

ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
fmt.Println(ac.FormatMoneyInt(500000)) // "£ 500,000"

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
    Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
fmt.Println(ac.FormatMoneyInt(1000000)) // "GBP 1,000,000"
fmt.Println(ac.FormatMoneyInt(-5000))   // "GBP (5,000)"
fmt.Println(ac.FormatMoneyInt(0))       // "GBP --"

FormatMoneyBigRat(value *big.Rat) string

FormatMoneyBigRat only supports *big.Rat value. It is faster than FormatMoney, because it does not do any runtime type evaluation.

Examples:

ac = accounting.Accounting{Symbol: "$", Precision: 2}
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(77777777, 3)))  // "$25,925,925.67"
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(-77777777, 3))) // "-$25,925,925.67"

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(77777777, 3)))  // "€25.925.925,67"

ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(77777777, 3)))  // "£ 25,925,926"

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
    Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(77777777, 3)))  // "GBP 25,925,926"
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(-77777777, 3))) // "GBP (25,925,926)"
fmt.Println(ac.FormatMoneyBigRat(big.NewRat(0, 3)))         // "GBP --"

FormatMoneyFloat64(value float64) string

FormatMoneyFloat64 only supports float64 value. It is faster than FormatMoney, because it does not do any runtime type evaluation.

Examples:

ac = accounting.Accounting{Symbol: "$", Precision: 2}
fmt.Println(ac.FormatMoneyFloat64(123456789.213123)) // "$123,456,789.21"
fmt.Println(ac.FormatMoneyFloat64(12345678))         // "$12,345,678.00"

ac = accounting.Accounting{Symbol: "€", Precision: 2, Thousand: ".", Decimal: ","}
fmt.Println(ac.FormatMoneyFloat64(4999.99))  // "€4.999,99"

ac = accounting.Accounting{Symbol: "£ ", Precision: 0}
fmt.Println(ac.FormatMoneyFloat64(500000)) // "£ 500,000"

ac = accounting.Accounting{Symbol: "GBP", Precision: 0,
    Format: "%s %v", FormatNegative: "%s (%v)", FormatZero: "%s --"}
fmt.Println(ac.FormatMoneyFloat64(1000000)) // "GBP 1,000,000"
fmt.Println(ac.FormatMoneyFloat64(-5000))   // "GBP (5,000)"
fmt.Println(ac.FormatMoneyFloat64(0))       // "GBP --"

FormatNumber(value interface{}, precision int, thousand string, decimal string) string

FormatNumber is a base function of the library which formats a number with custom precision and separators.

FormatNumber supports various types of value by runtime reflection. If you don't need runtime type evaluation, please refer to FormatNumberInt, FormatNumberBigRat, or FormatNumberFloat64.

• supported value types : int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64, *big.Rat

Examples:

fmt.Println(accounting.FormatNumber(123456789.213123, 3, ",", ".")) // "123,456,789.213"
fmt.Println(accounting.FormatNumber(1000000, 3, " ", ","))          // "1 000 000,000"

FormatNumberBigFloat(value *big.Float, precision int, thousand string, decimal string) string

(>= Go 1.5)

FormatNumberBigFloat only supports *big.Float value. It is faster than FormatNumber, because it does not do any runtime type evaluation.

Examples:

fmt.Println(accounting.FormatNumberBigFloat(big.NewFloat(123456789.213123), 3, ",", ".")) // "123,456,789.213"

FormatNumberInt(value int, precision int, thousand string, decimal string) string

FormatNumberInt only supports int value. It is faster than FormatNumber, because it does not do any runtime type evaluation.

Examples:

fmt.Println(accounting.FormatNumberInt(123456789, 3, ",", ".")) // "123,456,789.000"

FormatNumberBigRat(value *big.Rat, precision int, thousand string, decimal string) string

FormatNumberBigRat only supports *big.Rat value. It is faster than FormatNumber, because it does not do any runtime type evaluation.

Examples:

fmt.Println(accounting.FormatNumberBigRat(big.NewRat(77777777, 3), 3, ",", ".")) // "25,925,925.667"

FormatNumberFloat64(value float64, precision int, thousand string, decimal string) string

FormatNumberFloat64 only supports float64 value. It is faster than FormatNumber, because it does not do any runtime type evaluation.

Examples:

fmt.Println(accounting.FormatNumberFloat64(123456789.213123, 3, ",", ".")) // "123,456,789.213"