umath

Documentation

Overview

Package umath provides some useful unsigned math functions to prevent underflows. It also provides some type conversion functions to convert between different integer types to prevent underflows and overflows or overflows.

Index

• Variables
• func Len[T any](slice []T) uint64
• func MustToUint32[N constraints.Integer](i N) uint32
• func Subtract(a, b uint64) (uint64, bool)
• func SubtractOrZero(a, b uint64) uint64
• func ToInt32[N constraints.Integer](i N) (int32, error)
• func ToInt64[N constraints.Integer](n N) (int64, error)
• func ToUint32[N constraints.Integer](i N) (uint32, error)
• func ToUint64[N constraints.Integer](i N) (uint64, error)

Variables

var MaxUint128 = func() *big.Int {
	const twoPow128Sub1 = "340282366920938463463374607431768211455"
	maxUint128, ok := new(big.Int).SetString(twoPow128Sub1, 10)
	if !ok {
		panic("invalid max uint128")
	}

	return maxUint128
}()

var MaxUint256 = func() *big.Int {
	// Copied from uint256 package.
	const twoPow256Sub1 = "115792089237316195423570985008687907853269984665640564039457584007913129639935"
	maxUint256, ok := new(big.Int).SetString(twoPow256Sub1, 10)
	if !ok {
		panic("invalid max uint256")
	}

	return maxUint256
}()

MaxUint256 is the maximum value that can be represented by a uint256.

var MaxUint96 = func() *big.Int {
	const twoPow96Sub1 = "79228162514264337593543950335"
	maxUint96, ok := new(big.Int).SetString(twoPow96Sub1, 10)
	if !ok {
		panic("invalid max uint96")
	}

	return maxUint96
}()

Functions

func Len

func Len[T any](slice []T) uint64

Len returns the length of the slice as a uint64. This convenience function to avoid gosec complaining about uint64(len(slice)).

func MustToUint32

func MustToUint32[N constraints.Integer](i N) uint32

func Subtract

func Subtract(a, b uint64) (uint64, bool)

Subtract returns a - b and true if a >= b, otherwise 0 and false.

func SubtractOrZero

func SubtractOrZero(a, b uint64) uint64

SubtractOrZero returns a - b if a >= b, otherwise 0. This is a convenience function for inline usage.

func ToInt32

func ToInt32[N constraints.Integer](i N) (int32, error)

ToInt32 returns i as an int32 or an error if it cannot be represented as such.

func ToInt64

func ToInt64[N constraints.Integer](n N) (int64, error)

ToInt64 returns i as an int64 or an error if it cannot be represented as such.

func ToUint32

func ToUint32[N constraints.Integer](i N) (uint32, error)

ToUint32 returns i as an uint32 or an error if it cannot be represented as such.

func ToUint64

func ToUint64[N constraints.Integer](i N) (uint64, error)

ToUint64 returns i as an uint64 or an error if it cannot be represented as such.