You might as well make a datatype for "HashLiterals":

    data HashLiteral a = HashLiteral { _character :: Char, _trailingChars :: [Char], _representation :: [Char] -> a}

(Underscores for lenses) And then ``hashLiteralInfo :: [HashLiteral a]`` rather than an ad-hoc thing.

Then you could do something like

    binHashLiteral = HashLiteral { _char = 'b', _parser = Just . many . oneOf "01", _representation = Number . toInteger . fromBase 2 }

which has a nicer type (HashLiteral Number) than some weird nested tuple.