anchor.diff:  to_binstr(F) when is_float(F) -> list_to_binary(float_to_list(F));
   to_binstr(A) when is_atom(A) -> list_to_binary(atom_to_list(A));
   to_binstr(X) -> list_to_binary(io_lib:format("~p", [X])).
  +
  +list_to_binstr(X) -> 
  +    try list_to_binary(io_lib:format("~s", [X]))
  +    catch _:_ -> ?nav
  +    end.
   
   to_binary(B) when is_binary(B) ->   B;
   to_binary(I) when is_integer(I) -> <<I/integer>>;
  
positive.code: unary_fun_bind_type("map_size") ->              #bind{type=map,default= #{}};
  unary_fun_bind_type("from_binterm") ->          #bind{type=binterm,default= ?nav};
  unary_fun_bind_type("prefix_ul") ->             #bind{type=list,default= ?nav};
  unary_fun_bind_type("json_to_list") ->          #bind{type=json,default= []};
  unary_fun_bind_type("phash2") ->                #bind{type=term,default= []};
  unary_fun_bind_type("md5") ->                   #bind{type=binstr,default= <<>>};
  
negative.code: unary_fun_result_type("to_atom") ->             #bind{type=atom,default=?nav};
  unary_fun_result_type("to_binary") ->           #bind{type=binary,default=?nav};
  unary_fun_result_type("to_binstr") ->           #bind{type=binstr,default=?nav};
  unary_fun_result_type("list_to_binstr") ->      #bind{type=binstr,default=?nav};
  unary_fun_result_type("to_binterm") ->          #bind{type=binterm,default=?nav};
  unary_fun_result_type("to_boolean") ->          #bind{type=boolean,default=?nav};
  unary_fun_result_type("to_datetime") ->         #bind{type=datetime,default=?nav};
  