How to control if a list isn't void?

[salvomic]

(07-02-2015 02:20 PM)Helge Gabert Wrote:  When I tried it, I realized you need to convert into a string as well, i.e.

string(type(7°30'))==string(DOM_SPECIALFLOAT) returns 1.

I want save into →HMS() format...
I'm using this in my astronomy program: the initial input asks to save coordinates, if the user chooses yes it saves into an exported var, otherwise it set a default couple of coordinates, then if the var exists, the program load the var into two fields and set two vars (lat, long)...

Maybe to control only for type it's enough (why someone should change a var exported by the program?), but...