manveru

{lib, ...}: {
  toBase64 = text: let
    inherit (lib) sublist mod stringToCharacters concatMapStrings;
    inherit (lib.strings) charToInt;
    inherit (builtins) substring foldl' genList elemAt length concatStringsSep stringLength;
    lookup = stringToCharacters "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    sliceN = size: list: n: sublist (n * size) size list;
    pows = [(64 * 64 * 64) (64 * 64) 64 1];
    intSextets = i: map (j: mod (i / j) 64) pows;
    compose = f: g: x: f (g x);