inputs:

text: let
  inherit (inputs.nixpkgs.lib) sublist mod stringToCharacters concatMapStrings;
  inherit (inputs.nixpkgs.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);
  intToChar = elemAt lookup;
  convertTripletInt = sliceInt: concatMapStrings intToChar (intSextets sliceInt);
  sliceToInt = foldl' (acc: val: acc * 256 + val) 0;
  convertTriplet = compose convertTripletInt sliceToInt;
  join = concatStringsSep "";
  convertLastSlice = slice: let
    len = length slice;
  in
    if len == 1
    then (substring 0 2 (convertTripletInt ((sliceToInt slice) * 256 * 256))) + "=="
    else if len == 2
    then (substring 0 3 (convertTripletInt ((sliceToInt slice) * 256))) + "="
    else "";
  len = stringLength text;
  nFullSlices = len / 3;
  bytes = map charToInt (stringToCharacters text);
  tripletAt = sliceN 3 bytes;
  head = genList (compose convertTriplet tripletAt) nFullSlices;
  tail = convertLastSlice (tripletAt nFullSlices);

in
  join (head ++ [tail])