one.cry

b64map : [64][8]
b64map = ['A' .. 'Z'] # ['a' .. 'z'] # ['0' .. '9'] # ['/', '+']

toB64Char : [6] -> [8]
toB64Char x = b64map @ x

base64 xs = [ toB64Char x | x <- hexBytes ]
  where hexBytes = groupBy`{6} xs

passes = actual == expected
  where
    input = 0x49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d
    actual = base64 input
    expected = "SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t"