Learning Functional Programming in Go

The ChargeCard helper function

The ChargeCard function is a helper function used by the Charge filter to charge the credit card number found in the order. This implementation simply prints that the credit card was charged. It's a good placeholder for a real charge credit card logic:

func ChargeCard(ccardNo string, amount gc.USD) {
       fmt.Printf("Credit card %v%v charged %v\n", gu.Dashes(len(ccardNo)-4, "X"), ccardNo[len(ccardNo)-4:], amount)
}