geom: rewrite macros
geom: rewrite macros

make sure macros won't return the empty string (as error - quite
useless), at the same time, improve their error message.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb