@bbense: Your is_map returns true for any atom before nil, such as :nik or :a or :my_awesome_long_name.
The problem with those comparisons is that the domains of (most of?) the built-in types is unbound, e.g. there is no smallest number, longest string, biggest tuple, etc. so it becomes (near?) impossible to match for instance any number that is not an atom this way.
