# Pastebin xJDEEfRk
untilM p m = loop where
    loop = do
        a <- m
        if p a then pure [a] else (a :) <$> loop

getVarint = foldl' maskAndShift 0 <$> untilM endOfVarint getWord8 where
    maskAndShift acc byte = acc `shiftL` 7 .|. fromIntegral (clearBit byte 7)
    endOfVarint byte = not $ testBit byte 7