nix-dotfiles/extra/hex/default.nix

46 lines
898 B
Nix

{ pkgs, lib ? pkgs.lib, ... }:
let
inherit (lib.trivial) toHexString;
inherit (lib.strings) match toUpper stringToCharacters;
inherit (lib.lists) foldl;
# Parse a single hexadecimal digit to an integer
_parseDigit = c:
let
v = toUpper c;
in
assert(match "[0-9A-F]" v != null);
{
"0" = 0;
"1" = 1;
"2" = 2;
"3" = 3;
"4" = 4;
"5" = 5;
"6" = 6;
"7" = 7;
"8" = 8;
"9" = 9;
"A" = 10;
"B" = 11;
"C" = 12;
"D" = 13;
"E" = 14;
"F" = 15;
}."${v}";
in
rec {
# Convert an hexadecimal string to an integer
toDec = s:
let
characters = stringToCharacters s;
values = map _parseDigit characters;
in
foldl (acc: n: acc * 16 + n) 0 values;
# Convert an integer to a decimal string
fromDec = toHexString;
}