infra/users/lib.nix
2021-01-03 00:07:49 +01:00

17 lines
529 B
Nix

{ lib }:
let
chrs = lib.listToAttrs (lib.imap (i: v: { name = v; value = i + 96; }) lib.lowerChars);
ord = c: builtins.getAttr c chrs;
in
{
# Make a unique UID from a 4-char identifier
mkUid = id:
let
chars = lib.stringToCharacters (builtins.substring 0 4 id);
n = builtins.map (c: lib.mod (ord c) 10) chars;
s = builtins.concatStringsSep "" (builtins.map (i: builtins.toString i) n);
in
assert builtins.stringLength id >= 4;
assert builtins.length chars == 4;
1000 + lib.toInt s;
}