path: root/lib/hex.go

// Copyright © 2020 rsiddharth <s@ricketyspace.net>
// SPDX-License-Identifier: ISC

package lib

// Adapted from
// https://go.googlesource.com/go/+/refs/tags/go1.15/src/encoding/hex/hex.go#83
func HexCharToDec(c byte) uint16 {
	switch {
	case '0' <= c && c <= '9':
		return uint16(c - '0')
	case 'a' <= c && c <= 'f':
		return uint16(c - 'a' + 10)
	}
	return 0
}

func DecToHexChar(i uint16) byte {
	switch {
	case 0 <= i && i <= 9:
		return byte(48 + i)
	case 10 <= i && i <= 15:
		return byte(97 + (i - 10))
	}
	return 0
}