grokify/mogo

package currencyutil

import (
    "fmt"
    "strings"
)

type ExchangeRateSimple struct {
    BaseCurrency  string
    CurrencyRates map[string]float64
}

func (xr *ExchangeRateSimple) ConvertToBase(in float64, cur string) (float64, error) {
    cur = strings.ToUpper(strings.TrimSpace(cur))
    if multiplier, ok := xr.CurrencyRates[cur]; ok {
        return in * multiplier, nil
    }
    return in, fmt.Errorf("E_EXCHANGE_RATE_CANNOT_FIND [%s]", cur)
}

func ExampleExchangeRates() ExchangeRateSimple {
    return ExchangeRateSimple{
        BaseCurrency: "USD",
        CurrencyRates: map[string]float64{
            "AUD": 0.637368,
            "CAD": 0.709545,
            "EUR": 1.08641,
            "GBP": 1.24626,
            "USD": 1.0}}
}