Show currency in different locales

main.go

package main

import (
	"fmt"

	"golang.org/x/text/currency"
	"golang.org/x/text/language"
	"golang.org/x/text/message"
	"golang.org/x/text/number"
)

// CurrencyFormat defines all options to format currency name.
type CurrencyFormat struct {
	Unit    currency.Unit
	Display string
}

// CF makes a CurrencyFormat.
func CF(unit string, display string) *CurrencyFormat {
	return &CurrencyFormat{
		Unit:    currency.MustParseISO(unit),
		Display: display,
	}
}

var (
	cnZH = language.Make("cn-ZH")
	enUS = language.Make("en-US")
	esMX = language.Make("es-MX")
	enAU = language.Make("en-AU")
	jaJP = language.Make("ja-JP")
	esPE = language.Make("es-PE")

	currencies = map[language.Tag][]*CurrencyFormat{
		cnZH: {
			CF("CNY", "%m元"),
			CF("USD", "$%m"),
			CF("MXN", "$%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "%m円"),
		},

		enUS: {
			CF("CNY", "￥%m"),
			CF("USD", "$%m"),
			CF("MXN", "MXN $%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "¥%m"),
		},

		esMX: {
			CF("CNY", "￥%m"),
			CF("USD", "$%m"),
			CF("MXN", "MXN $%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "¥%m"),
		},

		enAU: {
			CF("CNY", "￥%m"),
			CF("USD", "$%m"),
			CF("MXN", "MXN $%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "¥%m"),
		},

		jaJP: {
			CF("CNY", "￥%m"),
			CF("USD", "$%m"),
			CF("MXN", "MXN $%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "%m円"),
		},

		esPE: {
			CF("CNY", "￥%m"),
			CF("USD", "$%m"),
			CF("MXN", "MXN $%m"),
			CF("AUD", "$%m"),
			CF("PEN", "S/ $%m"),
			CF("JPY", "¥%m"),
		},
	}

	// PEN is Peruvian sol.
	PEN              = currency.MustParseISO("PEN")
	currencyFraction = map[currency.Unit]int{
		currency.CNY: 2,
		currency.USD: 2,
		currency.MXN: 2,
		currency.AUD: 2,
		PEN:          2,
		currency.JPY: 0,
	}
)

func init() {
	for locale, formats := range currencies {
		for _, f := range formats {
			message.SetString(locale, f.Unit.String()+" %m", f.Display)
		}
	}
}

func formatCurrency(locale string, unit string, value interface{}) string {
	tag := language.Make(locale)
	printer := message.NewPrinter(tag)
	cu := currency.MustParseISO(unit)
	frac := currencyFraction[cu]
	format := unit + " %m"
	opts := []number.Option{
		number.IncrementString(fmt.Sprintf("0.%0[1]*d", frac+1, 5)),
		number.MaxFractionDigits(frac),
		number.MinFractionDigits(frac),
	}
	num := printer.Sprint(number.Decimal(value, opts...))
	return printer.Sprintf(format, num)
}

func main() {
	for _, unit := range []string{"CNY", "USD", "MXN", "AUD", "PEN", "JPY"} {
		for _, locale := range []string{"cn-ZH", "en-US", "es-MX", "en-AU", "ja-JP", "es-PE"} {
			fmt.Println(unit, locale, formatCurrency(locale, unit, 123456.789))
		}
	}
}

OUTPUT.txt

$ go run main.go
CNY cn-ZH 123,456.79元
CNY en-US ￥123,456.79
CNY es-MX ￥123,456.79
CNY en-AU ￥123,456.79
CNY ja-JP ￥123,456.79
CNY es-PE ￥123,456.79
USD cn-ZH $123,456.79
USD en-US $123,456.79
USD es-MX $123,456.79
USD en-AU $123,456.79
USD ja-JP $123,456.79
USD es-PE $123,456.79
MXN cn-ZH $123,456.79
MXN en-US MXN $123,456.79
MXN es-MX MXN $123,456.79
MXN en-AU MXN $123,456.79
MXN ja-JP MXN $123,456.79
MXN es-PE MXN $123,456.79
AUD cn-ZH $123,456.79
AUD en-US $123,456.79
AUD es-MX $123,456.79
AUD en-AU $123,456.79
AUD ja-JP $123,456.79
AUD es-PE $123,456.79
PEN cn-ZH S/ $123,456.79
PEN en-US S/ $123,456.79
PEN es-MX S/ $123,456.79
PEN en-AU S/ $123,456.79
PEN ja-JP S/ $123,456.79
PEN es-PE S/ $123,456.79
JPY cn-ZH 123,457円
JPY en-US ¥123,457
JPY es-MX ¥123,457
JPY en-AU ¥123,457
JPY ja-JP 123,457円
JPY es-PE ¥123,457