Currency amounts

Use xrpl/currency for exact XRP/drop conversions and calculations. 1 XRP is 1,000,000 drops. Use decimal strings rather than floating-point values when converting user input.

Convert XRP and drops

This example runs offline:

package main

import (
	"fmt"
	"log"

	"github.com/Peersyst/xrpl-go/xrpl/currency"
)

func main() {
	drops, err := currency.XrpToDrops("1.25")
	if err != nil {
		log.Fatal(err)
	}
	xrp, err := currency.DropsToXrp(drops)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println("Drops:", drops)
	fmt.Println("XRP:", xrp)
}

It prints 1250000 drops and 1.25 XRP. Both conversion functions validate the native XRP supply limit. XRP inputs must convert to a whole number of drops.

Calculate fees without losing precision

The immutable Drops type supports exact arithmetic. Its zero value is zero drops. Intermediate calculations can contain a fractional drop, but WholeString and XRPString require a whole number of drops.

For example, in a function returning an error:

base, err := currency.DropsFromXRP("0.000012")
if err != nil {
	return err
}
adjusted, err := base.MulDecimal("1.2")
if err != nil {
	return err
}
feeDrops, err := adjusted.Ceil().WholeString()
if err != nil {
	return err
}
fmt.Println(feeDrops) // 15

Choose rounding deliberately. Ceil rounds upward, while RoundHalfUp rounds to the nearest whole drop with halves rounded up. Drops also supports addition, integer/decimal/rational multiplication, comparison, and minimum selection.

Drops constructors do not enforce the protocol supply limit. Check final values against currency.MaxNativeDrops before protocol use. Do not confuse an intermediate calculation with an amount accepted by a transaction field.

Other currencies

ConvertStringToHex and ConvertHexToString handle non-standard currency-code strings. They do not convert balances or exchange rates. See XRPL currency formats for XRP, issued-currency, and MPT representations.

For transaction amount structs, use transaction/types. For the complete arithmetic API, use currency.